Research

21 pages, 5049 KiB

Open AccessArticle

New Insights into the Enhancement of Adventitious Root Formation Using N,N′-Bis(2,3-methylenedioxyphenyl)urea

by Ada Ricci, Eugenia Polverini, Stefano Bruno, Lucia Dramis, Daniela Ceresini, Antonio Scarano and Carmen Diaz-Sala

Plants 2023, 12(20), 3610; https://doi.org/10.3390/plants12203610 - 18 Oct 2023

Viewed by 908

Abstract

Adventitious rooting is a process of postembryonic organogenesis strongly affected by endogenous and exogenous factors. Although adventitious rooting has been exploited in vegetative propagation programs for many plant species, it is a bottleneck for vegetative multiplication of difficult-to-root species, such as many woody [...] Read more.

Adventitious rooting is a process of postembryonic organogenesis strongly affected by endogenous and exogenous factors. Although adventitious rooting has been exploited in vegetative propagation programs for many plant species, it is a bottleneck for vegetative multiplication of difficult-to-root species, such as many woody species. The purpose of this research was to understand how N,N′-bis-(2,3-methylenedioxyphenyl)urea could exert its already reported adventitious rooting adjuvant activity, starting from the widely accepted knowledge that adventitious rooting is a hormonally tuned progressive process. Here, by using specific in vitro bioassays, histological analyses, molecular docking simulations and in vitro enzymatic bioassays, we have demonstrated that this urea derivative does not interfere with polar auxin transport; it inhibits cytokinin oxidase/dehydrogenase (CKX); and, possibly, it interacts with the apoplastic portion of the auxin receptor ABP1. As a consequence of this dual binding capacity, the lifespan of endogenous cytokinins could be locally increased and, at the same time, auxin signaling could be favored. This combination of effects could lead to a cell fate transition, which, in turn, could result in increased adventitious rooting. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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16 pages, 18440 KiB

Open AccessArticle

The Effect of Topophysis on the In Vitro Development of Handroanthus guayacan and on Its Metabolism of Meta-Topolin Riboside

by Maroua Grira, Els Prinsen and Stefaan P. O. Werbrouck

Plants 2023, 12(20), 3577; https://doi.org/10.3390/plants12203577 - 15 Oct 2023

Viewed by 940

Abstract

An important factor affecting the uniformity of in vitro cultures is the topophysical position of the original explant. We investigated this phenomenon in Handroanthus guayacan, a tropical woody tree species. Shoots from a stock culture were separated into upper, middle and basal [...] Read more.

An important factor affecting the uniformity of in vitro cultures is the topophysical position of the original explant. We investigated this phenomenon in Handroanthus guayacan, a tropical woody tree species. Shoots from a stock culture were separated into upper, middle and basal sections and transferred to a modified MS medium containing meta-topolin-riboside and indole-butyric acid. After 8 weeks, the middle section produced the most shoots, the longest shoots and the highest number of nodes per plant. Shoots derived from the upper section were elongated, but had the shortest internodes, while those from the basal section formed the largest callus. None of the three types of explants rooted during the proliferation phase. The topophysically dependent spatial distribution of endogenous cytokinins and auxins was determined. The topophysical effect observed could not be explained solely by analyzing the endogenous isoprenoid and auxin. However, the metabolism and distribution of the aromatic cytokinin could provide an explanation. The concentration of the meta hydroxy-substituted topolins was highest in shoots derived from the middle section. Aromatic N- and O-glucosides were much more concentrated in the leaves than in the stems. In conclusion, it is recommended to consider the explant’s topophysis when developing a multiplication protocol to avoid heterogeneity in an in vitro culture. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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17 pages, 1533 KiB

Open AccessArticle

Tolerant Epitypes of Elicited Holm Oak Somatic Embryos Could Be Revealed by Challenges in Dual Culture with Phytophthora cinnamomi Rands

by Mar Ruiz-Galea, Carolina Kremer, Eva Friero and Inmaculada Hernández

Plants 2023, 12(17), 3056; https://doi.org/10.3390/plants12173056 - 25 Aug 2023

Viewed by 761

Abstract

Holm oaks (Quercus ilex L.) can suffer severe infection by the oomycete Phytophthora cinnamomi Rands; the production of more tolerant plants is, therefore, required. Embryo formation is a key period in the establishment of epigenetic memory. Somatic embryos from three holm oak [...] Read more.

Holm oaks (Quercus ilex L.) can suffer severe infection by the oomycete Phytophthora cinnamomi Rands; the production of more tolerant plants is, therefore, required. Embryo formation is a key period in the establishment of epigenetic memory. Somatic embryos from three holm oak genotypes were elicited, either over 3 days or 60 days, with methyl-jasmonate, salicylic acid (SA), β-aminobutyric acid (BABA), or benzothiadiazole (all at 50 μM and 100 μM), or 10% and 30% of a filtered oomycete extract (FILT10 and FILT30) to activate plant immune responses. The number of embryos produced and conversion rate under all conditions were recorded. Some elicited embryos were then exposed to P. cinnamomi in dual culture, and differential mycelial growth and the progression of necrosis were measured. The same was performed with the roots of germinated embryos. Within genotypes, significant differences were seen among the elicitation treatments in terms of both variables. Embryos and roots of 60-day BABA, SA, or FILT10 treatments inhibited mycelium growth. The 3-day BABA (either concentration) and 60-day FILT10 induced the greatest inhibition of necrosis. Mycelium and necrosis inhibition were compared with those of tolerant trees. Both inhibitions might be a defense response maintained after primed embryo germination, thus increasing the likelihood of tolerance to infection. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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13 pages, 1910 KiB

Open AccessArticle

In Vitro Propagation of the Blueberry ‘Blue Suede™’ (Vaccinium hybrid) in Semi-Solid Medium and Temporary Immersion Bioreactors

by Kim-Cuong Le, Shannon Johnson, Cyrus K. Aidun and Ulrika Egertsdotter

Plants 2023, 12(15), 2752; https://doi.org/10.3390/plants12152752 - 25 Jul 2023

Cited by 2 | Viewed by 1673

Abstract

The production of blueberries for fresh and processed consumption is increasing globally and has more than doubled in the last decade. Blueberry is grown commercially across a variety of climates in over 30 countries. The major classes of plants utilized for the planting [...] Read more.

The production of blueberries for fresh and processed consumption is increasing globally and has more than doubled in the last decade. Blueberry is grown commercially across a variety of climates in over 30 countries. The major classes of plants utilized for the planting and breeding of new cultivars are highbush, lowbush, half-high, Rabbiteye, and Southern highbush. Plants can be propagated by cuttings or in vitro micropropagation techniques. In vitro propagation offers advantages for faster generation of a large number of disease-free plants independent of season. Labor costs for in vitro propagation can be reduced using new cultivation technology and automation. Here, we test and demonstrate successful culture conditions and medium compositions for in vitro initiation, multiplication, and rooting of the Southern highbush cultivar ‘Blue Suede™’ (Vaccinium hybrid). Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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18 pages, 15743 KiB

Open AccessArticle

Expression of CsSCL1 and Rooting Response in Chestnut Leaves Are Dependent on the Auxin Polar Transport and the Ontogenetic Origin of the Tissues

by Elena Varas, Silvia Valladares, Jesús Vielba, Nieves Vidal and Conchi Sánchez

Plants 2023, 12(14), 2657; https://doi.org/10.3390/plants12142657 - 16 Jul 2023

Viewed by 780

Abstract

The mechanisms underlying the de novo regeneration of adventitious roots are still poorly understood, particularly in trees. We developed a system for studying adventitious rooting (AR) at physiological and molecular levels using leaves excised from chestnut microshoots of the same genotype but with [...] Read more.

The mechanisms underlying the de novo regeneration of adventitious roots are still poorly understood, particularly in trees. We developed a system for studying adventitious rooting (AR) at physiological and molecular levels using leaves excised from chestnut microshoots of the same genotype but with two distinct ontogenetic origins that differ in rooting competence. Leaves were treated with auxin and N-1-naphthyl-phthalamic acid (NPA), an inhibitor of auxin polar transport (PAT). The physiological effects were investigated by recording rooting rates and the number and quality of the roots. Molecular responses were examined by localizing and monitoring the changes in the expression of CsSCL1, an auxin-inducible gene in juvenile and mature shoots during AR. The rooting response of leaves was ontogenetic-stage dependent and similar to that of the donor microshoots. Initiation of root primordia and root development were inhibited by application of NPA, although its effect depended on the timing of application. CsSCL1 was upregulated by auxin only in rooting-competent leaves during the novo root organogenesis, and the expression was reduced by NPA. The inhibitory effect on gene expression was detected during the reprograming of rooting competent cells towards root initials in response to auxin, indicating that PAT-mediated upregulation of CsSCL1 is required in the initial steps of AR in chestnut leaves. The localized expression of CsSCL1 in the quiescent center (QC) also suggests a role for this gene in the maintenance of meristematic competence and root radial patterning. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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15 pages, 3720 KiB

Open AccessArticle

Successful In Vitro Shoot Multiplication of Quercus robur L. Trees Aged up to 800 Years

by Paweł Chmielarz, Szymon Kotlarski, Ewa Marzena Kalemba, João Paulo Rodrigues Martins and Marcin Michalak

Plants 2023, 12(12), 2230; https://doi.org/10.3390/plants12122230 - 06 Jun 2023

Cited by 5 | Viewed by 1864

Abstract

The conservation of the genetic resources of old trees is crucial to their ecological role but is extremely difficult, especially for oak species (Quercus spp.) displaying recalcitrance in seed and vegetative propagation methods. Our study aimed to assess the regenerative potential of [...] Read more.

The conservation of the genetic resources of old trees is crucial to their ecological role but is extremely difficult, especially for oak species (Quercus spp.) displaying recalcitrance in seed and vegetative propagation methods. Our study aimed to assess the regenerative potential of Quercus robur trees of different ages (up to 800 years) during micropropagation. We also aimed to determine how in vitro conditions can influence in vitro regeneration responses. Lignified branches collected from 67 selected trees were cultivated ex vitro in culture pots at 25 °C to obtain epicormic shoots (explant sources). The explants were cultivated on an agar medium supplemented with 0.8 mg L⁻¹ 6-benzylaminopurine (BAP) for at least 21 months. In a second experiment, two different shoot multiplication conditions (temporary immersion—RITA^® bioreactor and agar medium) and two culture medium formulations (Woody Plant Medium and modified Quoirin and Lepoivre medium) were tested. The results showed that the mean length of the epicormic shoots obtained in a pot culture was a function of donor age and was similar among the group of younger trees (ca. 20–200 years), and varied between older trees (ca. 300–800 years). The efficiency of in vitro shoot multiplication strictly depended on the genotype. A sustainable in vitro culture (defined as survival after 6 months) was only possible for half of the tested old donor trees, even when they survived the first month of in vitro growth. A continuous monthly increase in the number of in vitro cultured shoots was reported in younger oaks and in some old oaks. We found a significant effect of the culture system and the macro- and micronutrient composition on in vitro shoot growth. This is the first report demonstrating that the in vitro culture can be successfully applied to the propagation of even 800-year-old pedunculate oak trees. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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25 pages, 7122 KiB

Open AccessArticle

Application of Cold Storage and Short In Vitro Germination for Somatic Embryos of Pinus radiata and P. sylvestris

by Cathie Reeves, Mikko Tikkinen, Tuija Aronen and Jana Krajnakova

Plants 2023, 12(11), 2095; https://doi.org/10.3390/plants12112095 - 24 May 2023

Cited by 3 | Viewed by 1434

Abstract

Somatic embryogenesis (SE) is an advanced vegetative propagation technology that, when used in combination with breeding and cryopreservation, offers the forest industry a powerful tool for the deployment of elite genotypes. Germination and acclimatization are critical and cost-intensive phases in the production of [...] Read more.

Somatic embryogenesis (SE) is an advanced vegetative propagation technology that, when used in combination with breeding and cryopreservation, offers the forest industry a powerful tool for the deployment of elite genotypes. Germination and acclimatization are critical and cost-intensive phases in the production of somatic plants. The efficient conversion of somatic embryos into robust plants is a necessity if a propagation protocol is to be successfully adopted by the industry. In this work, these late phases of the SE protocol of two pine species were investigated. A shortened germination protocol and more controlled acclimatization were investigated for Pinus radiata, testing embryos from 18 embryogenic cell lines. A more simplified protocol, including a cold storage phase, was also compared among 10 of these cell lines. A shortened germination period and more controlled protocols significantly improved the acclimatization of somatic embryos directly from the lab to the glasshouse. When results for all cell lines were pooled, there were significant improvements in all growth characteristics (shoot height, root length, root collar diameter, and root quadrant score). When the more simplified protocol involving cold storage was tested, improvements were seen in the root architecture. For Pinus sylvestris, the late phases of somatic embryogenesis were investigated on seven cell lines in a set of two trials (four to seven cell lines per trial). During the germination phase, a shortened and simplified in vitro period, a cold storage option and basal media were explored. Viable plants were obtained from all treatments. However, there is still the need to improve germination and related protocols together with growing regimes for Pinus sylvestris. The improvements to protocols presented here, particularly for Pinus radiata, result in greater survival and quality of somatic emblings, leading to reduced costs and increased confidence in the technology. Simplified protocols using a cold storage option show great promise and, with some further research, could lead to reductions in the cost of the technology. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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18 pages, 6214 KiB

Open AccessArticle

Morpho-Physiological Evaluation of Solanum betaceum Cav. In Vitro Cloned Plants: A Comparison of Different Micropropagation Methods

by Mariana Correia, Tércia Lopes, Ana Patrícia Puga, Glória Pinto, Jorge Canhoto and Sandra Correia

Plants 2023, 12(9), 1884; https://doi.org/10.3390/plants12091884 - 05 May 2023

Cited by 1 | Viewed by 1616

Abstract

Tamarillo (Solanum betaceum Cav.) is a subtropical solanaceous tree with increasing agronomic interest due to its nutritious edible fruits. Growing demand for tamarillo plants and fruits requires optimization of existing propagation methods and scaled-up systems for large-scale cloning of selected germplasm. Three [...] Read more.

Tamarillo (Solanum betaceum Cav.) is a subtropical solanaceous tree with increasing agronomic interest due to its nutritious edible fruits. Growing demand for tamarillo plants and fruits requires optimization of existing propagation methods and scaled-up systems for large-scale cloning of selected germplasm. Three in vitro protocols have been used to micropropagate tamarillo: (1) axillary shoot proliferation in a semisolid medium, (2) organogenesis, and (3) somatic embryogenesis procedures. Variables such as the age of the established shoot cultures and rooting treatments were also analyzed. The morphological and physiological quality of acclimatized plants derived from all the methodologies were compared, with seed-derived plants used as a control group. Overall, the results show that in vitro-derived plants have a similar development to seed-derived plants. Micropropagation by axillary shoot proliferation was highly efficient, with rooting rates above 80% in most treatments. Organogenesis induction was more effective from lamina explants using MS media with 2.0 mg·L⁻¹ 6-benzylaminopurine. Both organogenesis and somatic embryogenesis-derived plants were also morphologically and physiologically equivalent to seed and axillary shoot-derived plants. The specificities of each micropropagation method are discussed. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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16 pages, 5156 KiB

Open AccessArticle

Ethylene Inhibition Reduces De Novo Shoot Organogenesis and Subsequent Plant Development from Leaf Explants of Solanum betaceum Cav.

by Mariana Neves, Sandra Correia and Jorge Canhoto

Plants 2023, 12(9), 1854; https://doi.org/10.3390/plants12091854 - 30 Apr 2023

Cited by 2 | Viewed by 1744

Abstract

In de novo shoot organogenesis (DNSO) plant cells develop into new shoots, without the need of an existing meristem. Generally, this process is triggered by wounding and specific growth regulators, such as auxins and cytokinins. Despite the potential significance of the plant hormone [...] Read more.

In de novo shoot organogenesis (DNSO) plant cells develop into new shoots, without the need of an existing meristem. Generally, this process is triggered by wounding and specific growth regulators, such as auxins and cytokinins. Despite the potential significance of the plant hormone ethylene in DNSO, its effect in regeneration processes of woody species has not been thoroughly investigated. To address this gap, Solanum betaceum Cav. was used as an experimental model to explore the role of this hormone on DNSO and potentially extend the findings to other woody species. In this work it was shown that ethylene positively regulates DNSO from tamarillo leaf explants. Ethylene precursors ACC and ethephon stimulated shoot regeneration by increasing the number of buds and shoots regenerated. In contrast, the inhibition of ethylene biosynthesis or perception by AVG and AgNO₃ decreased shoot regeneration. Organogenic callus induced in the presence of ethylene precursors showed an upregulated expression of the auxin efflux carrier gene PIN1, suggesting that ethylene may enhance shoot regeneration by affecting auxin distribution prior to shoot development. Additionally, it was found that the de novo shoot meristems induced in explants in which ethylene biosynthesis and perception was suppressed were unable to further develop into elongated shoots. Overall, these results imply that altering ethylene levels and perception could enhance shoot regeneration efficiency in tamarillo. Moreover, we offer insights into the possible molecular mechanisms involved in ethylene-induced shoot regeneration. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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17 pages, 2315 KiB

Open AccessArticle

The Effect of Silver Nanoparticle Addition on Micropropagation of Apricot Cultivars (Prunus armeniaca L.) in Semisolid and Liquid Media

by Cristian Pérez-Caselles, Lorenzo Burgos, Inmaculada Sánchez-Balibrea, Jose A. Egea, Lydia Faize, Marina Martín-Valmaseda, Nina Bogdanchikova, Alexey Pestryakov and Nuria Alburquerque

Plants 2023, 12(7), 1547; https://doi.org/10.3390/plants12071547 - 03 Apr 2023

Cited by 3 | Viewed by 1775

Abstract

Silver nanoparticles (AgNPs) are novel compounds used as antimicrobial and antiviral agents. In addition, AgNPs have been used to improve the growth of different plants, as well as the in vitro multiplication of plant material. In this work the effect of AgNPs on [...] Read more.

Silver nanoparticles (AgNPs) are novel compounds used as antimicrobial and antiviral agents. In addition, AgNPs have been used to improve the growth of different plants, as well as the in vitro multiplication of plant material. In this work the effect of AgNPs on in vitro growth of ‘Canino’ and ‘Mirlo Rojo’ cultivars, as well as the leaf ion composition, are studied. Different concentrations of AgNPs (0, 25, 50, 75 and 100 mg L⁻¹) were added to two culture systems: semisolid medium with agar (SSM) in jars and liquid medium in temporary immersion system (TIS). Proliferation (number of shoots), shoot length, productivity (number of shoot × average length), leaf surface, fresh and dry weight were measured. Additionally, the silver and other ion accumulation in the leaves were evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. The productivity of ‘Canino’ and ‘Mirlo Rojo’ decreased when increasing the concentration of AgNPs in the semisolid medium. However, the use of AgNPs in the TIS improved the proliferation and productivity of ‘Canino’ and Mirlo Rojo’, increasing biomass production, and the concentration of nutrients in the plants, although these effects are genotype-dependent. TISs are the best system for introducing silver into shoots, the optimum concentration being 50 mg L⁻¹ for ‘Canino’ and 75 mg L⁻¹ for ‘Mirlo Rojo’. Principal component analysis, considering all the analyzed ions along the treatments, separates samples in two clear groups related to the culture system used. The use of bioreactors with a liquid medium has improved the productivity of ‘Canino’ and ‘Mirlo Rojo’ in the proliferation stage, avoiding hyperhydration and other disorders. The amount of metallic silver that penetrates apricot plant tissues depends on the culture system, cultivar and concentration of AgNPs added to the culture medium. Silver ion accumulation measured in the shoots grown in the TIS was higher than in shoots micropropagated in a semisolid medium, where it is barely detectable. Furthermore, AgNPs had a beneficial effect on plants grown in TIS. However, AgNPs had a detrimental effect when added to a semisolid medium. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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11 pages, 1494 KiB

Open AccessArticle

Effects of Monochromatic Light on Growth and Quality of Pistacia vera L.

by Dhekra Abdouli, Sihem Soufi, Taoufik Bettaieb and Stefaan P. O. Werbrouck

Plants 2023, 12(7), 1546; https://doi.org/10.3390/plants12071546 - 03 Apr 2023

Cited by 1 | Viewed by 1250

Abstract

Light-emitting diodes (LEDs) are popular as a light source for in vitro plants because they save energy and allow the morphology of the plant to be altered. The purpose of this study was to show that switching from classical fluorescent light (FL) to [...] Read more.

Light-emitting diodes (LEDs) are popular as a light source for in vitro plants because they save energy and allow the morphology of the plant to be altered. The purpose of this study was to show that switching from classical fluorescent light (FL) to LED light can have both beneficial and adverse effects. Pistacia vera plantlets were exposed to FL, monochromatic Blue LED light (B), monochromatic Red LED light (R), and a 1:1 mixture of both B and R (BR). R increased the total weight, shoot length, number of shoots ≥ 1 cm, and proliferation. It also reduced hyperhydricity (HH), but also dramatically increased shoot tip necrosis (STN) and leaf necrosis (LN). B cured plants of HH and STN, but hardly enabled proliferation. It did not solve the problem of LN, but the plants were high in total chlorophyll and carotenoids. BR reduced HH but enabled limited proliferation, high STN, and LN. All three LED treatments reduced HH compared to FL. B induced both high total phenolic and flavonoid content and high DPPH-scavenging activity. These results show that switching from FL to LED can have a significant positive or negative effect on proliferation and quality. This suggests that finding an optimal lighting regimen will take a lot of trial and error. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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16 pages, 7392 KiB

Open AccessArticle

Dynamics of Endogenous Auxin and Its Role in Somatic Embryogenesis Induction and Progression in Cork Oak

by Elena Carneros, Jorge Sánchez-Muñoz, Yolanda Pérez-Pérez, Beatriz Pintos, Aránzazu Gómez-Garay and Pilar S. Testillano

Plants 2023, 12(7), 1542; https://doi.org/10.3390/plants12071542 - 03 Apr 2023

Cited by 3 | Viewed by 1689

Abstract

Somatic embryogenesis (SE) is a feasible in vitro regeneration system with biotechnological applications in breeding programs, although, in many forest species, SE is highly inefficient, mainly due to their recalcitrance. On the other hand, SE represents a valuable model system for studies on [...] Read more.

Somatic embryogenesis (SE) is a feasible in vitro regeneration system with biotechnological applications in breeding programs, although, in many forest species, SE is highly inefficient, mainly due to their recalcitrance. On the other hand, SE represents a valuable model system for studies on cell reprogramming, totipotency acquisition, and embryogenic development. The molecular mechanisms that govern the transition of plant somatic cells to embryogenic cells are largely unknown. There is increasing evidence that auxins mediate this transition and play a key role in somatic embryo development, although data on woody species are very limited. In this study, we analyzed the dynamics and possible role of endogenous auxin during SE in cork oak (Quercus suber L.). The auxin content was low in somatic cells before cell reprogramming, while it increased after induction of embryogenesis, as revealed by immunofluorescence assays. Cellular accumulation of endogenous auxin was also detected at the later stages of somatic embryo development. These changes in auxin levels correlated with the expression patterns of the auxin biosynthesis (QsTAR2) and signaling (QsARF5) genes, which were upregulated after SE induction. Treatments with the inhibitor of auxin biosynthesis, kynurenine, reduced the proliferation of proembryogenic masses and impaired further embryo development. QsTAR2 and QsARF5 were downregulated after kynurenine treatment. Our findings indicate a key role of endogenous auxin biosynthesis and signaling in SE induction and multiplication, as well as somatic embryo development of cork oak. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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18 pages, 2899 KiB

Open AccessArticle

Testing Explant Sources, Culture Media, and Light Conditions for the Improvement of Organogenesis in Pinus ponderosa (P. Lawson and C. Lawson)

by Alejandra Rojas-Vargas, Ander Castander-Olarieta, Antonia Maiara Marques do Nascimento, María Laura Vélez, Cátia Pereira, João Martins, Mónica Zuzarte, Jorge Canhoto, Itziar A. Montalbán and Paloma Moncaleán

Plants 2023, 12(4), 850; https://doi.org/10.3390/plants12040850 - 14 Feb 2023

Cited by 1 | Viewed by 1718

Abstract

Pinus. ponderosa (P. Lawson and C. Lawson) is a commercial tree and one of the most important forest species in North America. Ponderosa pine suffers hardship when going through vegetative propagation and, in some cases, 15–30 years are needed to achieve full reproductive [...] Read more.

Pinus. ponderosa (P. Lawson and C. Lawson) is a commercial tree and one of the most important forest species in North America. Ponderosa pine suffers hardship when going through vegetative propagation and, in some cases, 15–30 years are needed to achieve full reproductive capacity. Based on previous works on P. ponderosa regeneration through in vitro organogenesis and trying to improve the published protocols, our objective was to analyze the influence of different types of explants, basal culture media, cytokinins, auxins, and light treatments on the success of shoot multiplication and rooting phases. Whole zygotic embryos and 44 µΜ 6-benzyladenine showed the best results in terms of explants survival. For shoot organogenesis, whole zygotic embryos and half LP (LP medium, Quoirin and Lepoivre, 1977, modified by Aitken-Christie et al., 1988) macronutrients were selected. A significant positive interaction between whole zygotic embryos and half LP macronutrients was found for the percentage of explants forming shoots. Regarding the light treatments applied, a significantly higher percentage of shoots elongated enough to be rooted was detected in shoots growing under blue LED at a light intensity of 61.09 µmol m⁻² s⁻¹. However, the acclimatization percentage was higher in shoots previously cultivated under fluorescent light at a light intensity of 61.71 µmol m⁻² s⁻¹. Anatomical studies using light microscopy and scanning electron microscopy showed the light treatments promoted differences in anatomical aspects in in vitro shoots; needles of plantlets exposed to red and blue LEDs revealed less stomata compared with needles from plantlets exposed to fluorescent light. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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15 pages, 3791 KiB

Open AccessArticle

Assessing Effect of Rootstock Micropropagation on Field Performance of Grafted Peach Varieties by Fitting Mixed-Effects Models: A Longitudinal Study

by Juan A. Marín, Elena García, Pilar Lorente, Pilar Andreu and Arancha Arbeloa

Plants 2023, 12(3), 674; https://doi.org/10.3390/plants12030674 - 03 Feb 2023

Viewed by 1194

Abstract

Rootstock micropropagation has been extensively used as an alternative to propagation by cuttings. Although studies have recently been conducted on other species, no conclusive reports have been published on the effect of rootstock micropropagation on the field performance of fruit trees. Here, we [...] Read more.

Rootstock micropropagation has been extensively used as an alternative to propagation by cuttings. Although studies have recently been conducted on other species, no conclusive reports have been published on the effect of rootstock micropropagation on the field performance of fruit trees. Here, we present the results of a five-year study of peach varieties grafted on two rootstocks (Adesoto 101 and Adafuel), either micropropagated or propagated by cuttings, to ascertain the effect of the rootstock propagation method on field performance. Fruit trees are woody plants with a long life cycle; so, to reduce the influence of environmental or cultural factors on the agronomical results, studies need to last for several years, in which data are obtained from the same individuals over time (longitudinal data). This hinders the analysis because these data lack independence. In contrast with a more traditional approach with data aggregation and repeated-measures ANOVA analysis, in this study, we used linear mixed-effects models to control the variance associated with random factors without data aggregation. The growth of the fruit trees did not appreciably differ between the rootstock propagation methods, neither in the flowering period nor in the yield. The models constructed for different parameters of the field performance (trunk cross-sectional area (TCSA), cumulative yield, cumulative yield efficiency, and cumulative crop load) showed a very good fit (R² > 0.97), allowing the conclusion that the rootstock propagation method did not affect the field performance of fruit trees in this study. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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20 pages, 4669 KiB

Open AccessArticle

Micropropagation as a Tool for the Conservation of Autochthonous Sorbus Species of Czechia

by Jana Šedivá, Jiří Velebil and Daniel Zahradník

Plants 2023, 12(3), 488; https://doi.org/10.3390/plants12030488 - 20 Jan 2023

Cited by 4 | Viewed by 1380

Abstract

Members of the genus Sorbus are the only endemic tree species that occur in Czechia. They are important components of endangered plant communities. Their natural regeneration is usually problematic because of their mode of reproduction and because they can survive in rare populations [...] Read more.

Members of the genus Sorbus are the only endemic tree species that occur in Czechia. They are important components of endangered plant communities. Their natural regeneration is usually problematic because of their mode of reproduction and because they can survive in rare populations with small numbers of individuals. The aim of this study was to develop a successful micropropagation protocol for selected Sorbus species, of which two are endemic (S. gemella and S. omissa) and two are hybrid (S. × abscondita and S. × kitaibeliana). We found significant differences in shoot induction and rooting ability between the Sorbus species under study. With the exception of S. × abscondita, N⁶-benzyladenine had a significantly greater effect on shoot regeneration, both in terms of shoot number and total shoot length, than meta-topolin. Root induction was key to the successful micropropagation of the Sorbus species studied. Our results show that four Sorbus species can be successfully rooted under ex vitro conditions, without a rooting powder treatment in a steamed peat-perlite substrate. Auxin-untreated microcuttings of S. gemella, S. × kitaibeliana and S. omissa, but not S. × abscondita, rooted better than ones treated with indole-3-butyric acid. This is the first time a micropropagation protocol for S. omissa, S. × abscondita and S. × kitaibeliana has been published. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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17 pages, 4275 KiB

Open AccessFeature PaperArticle

Effect of Soil Type and In Vitro Proliferation Conditions on Acclimation and Growth of Willow Shoots Micropropagated in Continuous Immersion Bioreactors

by Carmen Trasar-Cepeda, Conchi Sánchez, Mar Casalderrey, Diana Bello, Jesús María Vielba, Saleta Rico, Anxela Aldrey and Nieves Vidal

Plants 2023, 12(1), 132; https://doi.org/10.3390/plants12010132 - 27 Dec 2022

Viewed by 1758

Abstract

Salix viminalis L. is a species with high capacity for micropropagation and acclimation and could therefore be used to evaluate emergent techniques in the field of plant propagation. The aims of this study were to propagate willow in liquid medium with a continuous [...] Read more.

Salix viminalis L. is a species with high capacity for micropropagation and acclimation and could therefore be used to evaluate emergent techniques in the field of plant propagation. The aims of this study were to propagate willow in liquid medium with a continuous immersion system, to explore the application of photoautotrophic conditions and to investigate the adaptation of willow plantlets to different soils that could be used as alternatives to commercial peat. For proliferation, we used 3% sucrose or sugar-free medium, and as substrates, we used commercial peat, a soil from an oak forest with high organic matter content and a crop soil with low organic matter content. The effect of sugar supplementation during proliferation and the soil characteristics during acclimation and growth were evaluated on the basis of aerial and root growth and the hydrolytic and dehydrogenase enzymatic activities of the soils. The results indicate that under photoautotrophic conditions, the supplementation of sucrose during micropropagation did not affect the subsequent growth of the plantlets. All plants acclimated without loss, but the type of soil influenced the height and vigor. Plants produced the highest shoots in peat, whereas the most root development occurred in crop soil. Soil enzyme activities were more influenced by the type of soil than by the presence of plants. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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11 pages, 1532 KiB

Open AccessArticle

Micropropagation of Citronella mucronata D. Don, a Vulnerable Chilean Endemic Tree Species

by Francesca Guerra, Loreto Badilla, Ricardo Cautin and Mónica Castro

Plants 2022, 11(18), 2425; https://doi.org/10.3390/plants11182425 - 16 Sep 2022

Cited by 4 | Viewed by 1871

Abstract

Citronella mucronata (C. mucronata), a tree species endemic to Chile, has become threatened in its natural habitat and is currently listed as vulnerable. Tree population parameters have deteriorated due to indiscriminate logging and other anthropogenic activities, warranting research on mass propagation [...] Read more.

Citronella mucronata (C. mucronata), a tree species endemic to Chile, has become threatened in its natural habitat and is currently listed as vulnerable. Tree population parameters have deteriorated due to indiscriminate logging and other anthropogenic activities, warranting research on mass propagation as a means of recovery. This study, unprecedented for this native species, has developed a successful method for its micropropagation. The objective was to establish a protocol for in vitro propagation of C. mucronata to produce large quantities of high-quality seedlings in an accelerated plant acquisition process. The best results were achieved by growing explants on Murashige and Skoog (MS) basal culture medium supplemented with 4.44 μM 6-benzylaminopurine (BAP) and 14.76 μM indole-3-butyric acid (IBA). Explant survival rate was 78 %, the average shoot length reached 3.2 cm, the number of lateral shoots was 3.9, and rooting rate was 60%. Furthermore, stimulation with red and blue light in a 1:2 ratio, supplemented with 14.76 μM IBA, improved the rooting rate to 93%. The survival rate of rooted explants reached 100% in the acclimatization stage when using peat and perlite substrate (1:1 v/v). Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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13 pages, 2735 KiB

Open AccessArticle

Identification of Early Salt-Stress-Responsive Proteins in In Vitro Prunus Cultured Excised Roots

by Emma Sevilla, Pilar Andreu, María F. Fillat, M. Luisa Peleato, Juan A. Marín and Arancha Arbeloa

Plants 2022, 11(16), 2101; https://doi.org/10.3390/plants11162101 - 12 Aug 2022

Cited by 2 | Viewed by 1205

Abstract

Fruit-tree rootstock selection is a challenge under a scenario of growing environmental stresses in which the soil and climate are greatly affected. Salinization is an increasing global process that severely affects soil fertility. The selection of rootstocks with the ability to tolerate salt [...] Read more.

Fruit-tree rootstock selection is a challenge under a scenario of growing environmental stresses in which the soil and climate are greatly affected. Salinization is an increasing global process that severely affects soil fertility. The selection of rootstocks with the ability to tolerate salt stress is essential. Excised root cultures may be an excellent experimental approach to study stress physiology and a predictive tool to assess possible tolerance. In this study, we show how protein changes in response to salt stress evaluated in excised root cultures of Prunus cerasus (moderate salt-sensitive cultivar) could be representative of these changes in the roots of whole plants. The 2D electrophoresis of root extracts and subsequent spot identification by MALDI-TOF/TOF-MS show 16 relevant proteins differentially expressed in roots as a response to 60 mM NaCl. Cytoplasmic isozyme fructose 1,6-bisphosphate aldolase shows relevant changes in its relative presence of isoforms as a response to saline stress, while the total level of enzymes remains similar. Ferredoxin-NADP⁺ reductase increases as a response to salinity, even though the measured activity is not significantly different. The observed changes are congruent with previous proteomic studies on the roots of whole plants that are involved in protection mechanisms against salt stress. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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22 pages, 3060 KiB

Open AccessEditor’s ChoiceArticle

Artificial Neural Networks Elucidated the Essential Role of Mineral Nutrients versus Vitamins and Plant Growth Regulators in Achieving Healthy Micropropagated Plants

by Tomás A. Arteta, Radhia Hameg, Mariana Landin, Pedro P. Gallego and M. Esther Barreal

Plants 2022, 11(10), 1284; https://doi.org/10.3390/plants11101284 - 11 May 2022

Cited by 7 | Viewed by 2149

Abstract

The design of an adequate culture medium is an essential step in the micropropagation process of plant species. Adjustment and balance of medium components involve the interaction of several factors, such as mineral nutrients, vitamins, and plant growth regulators (PGRs). This work aimed [...] Read more.

The design of an adequate culture medium is an essential step in the micropropagation process of plant species. Adjustment and balance of medium components involve the interaction of several factors, such as mineral nutrients, vitamins, and plant growth regulators (PGRs). This work aimed to shed light on the role of these three components on the plant growth and quality of micropropagated woody plants, using Actinidia arguta as a plant model. Two experiments using a five-dimensional experimental design space were defined using the Design of Experiments (DoE) method, to study the effect of five mineral factors (NH₄NO₃, KNO₃, Mesos, Micros, and Iron) and five vitamins (Myo-inositol, thiamine, nicotinic acid, pyridoxine, and vitamin E). A third experiment, using 20 combinations of two PGRs: BAP (6-benzylaminopurine) and GA₃ (gibberellic acid) was performed. Artificial Neural Networks (ANNs) algorithms were used to build models with the whole database to determine the effect of those components on several growth and quality parameters. Neurofuzzy logic allowed us to decipher and generate new knowledge on the hierarchy of some minerals as essential components of the culture media over vitamins and PRGs, suggesting rules about how MS basal media formulation could be modified to assess the quality of micropropagated woody plants. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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15 pages, 53581 KiB

Open AccessEditor’s ChoiceArticle

Effect of Sucrose on Growth and Stress Status of Castanea sativa x C. crenata Shoots Cultured in Liquid Medium

by Diego Gago, María Ángeles Bernal, Conchi Sánchez, Anxela Aldrey, Beatriz Cuenca, Colin Bruce Christie and Nieves Vidal

Plants 2022, 11(7), 965; https://doi.org/10.3390/plants11070965 - 01 Apr 2022

Cited by 13 | Viewed by 2540

Abstract

Current breeding programs aim to increase the number of ink-tolerant chestnut trees using vegetative propagation of selected genotypes. However, the commercial vegetative propagation of chestnut species is still a bottleneck for the forest industry, mainly due to problems in the rooting and acclimation [...] Read more.

Current breeding programs aim to increase the number of ink-tolerant chestnut trees using vegetative propagation of selected genotypes. However, the commercial vegetative propagation of chestnut species is still a bottleneck for the forest industry, mainly due to problems in the rooting and acclimation of propagules. This study aimed to explore the potential benefits of decreasing sucrose supplementation during chestnut micropropagation. Explants were cultured with high light intensity and CO₂-enriched air in temporary or continuous immersion bioreactors and with different sucrose supplementation to evaluate the impact of these treatments on growth, rooting and physiological status (monosaccharide content, soluble phenolics and antioxidant activity). The proliferation and rooting performance of shoots cultured by continuous immersion decreased sharply with sucrose concentrations lower than 1%, whereas shoots cultured by temporary immersion grew and rooted successfully with 0.5% sucrose. These results suggest this system is appropriate to culture chestnut with low sucrose concentration and to explore photoautotrophic propagation of this species. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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Review

Jump to: Research, Other

18 pages, 379 KiB

Open AccessReview

Somatic Embryogenesis in Conifers: One Clade to Rule Them All?

by Hugo Pacheco de Freitas Fraga, Paula Eduarda Cardoso Moraes, Leila do Nascimento Vieira and Miguel Pedro Guerra

Plants 2023, 12(14), 2648; https://doi.org/10.3390/plants12142648 - 14 Jul 2023

Viewed by 1637

Abstract

Somatic embryogenesis (SE) in conifers is usually characterized as a multi-step process starting with the development of proembryogenic cell masses and followed by histodifferentiation, somatic embryo development, maturation, desiccation, and plant regeneration. Our current understanding of conifers’ SE is mainly derived from studies [...] Read more.

Somatic embryogenesis (SE) in conifers is usually characterized as a multi-step process starting with the development of proembryogenic cell masses and followed by histodifferentiation, somatic embryo development, maturation, desiccation, and plant regeneration. Our current understanding of conifers’ SE is mainly derived from studies using Pinaceae species as a model. However, the evolutionary relationships between conifers are not clear. Some hypotheses consider conifers as a paraphyletic group and Gnetales as a closely related clade. In this review, we used an integrated approach in order to cover the advances in knowledge on SE in conifers and Gnetales, discussing the state-of-the-art and shedding light on similarities and current bottlenecks. With this approach, we expect to be able to better understand the integration of these clades within current studies on SE. Finally, the points discussed raise an intriguing question: are non-Pinaceae conifers less prone to expressing embryogenic competence and generating somatic embryos as compared to Pinaceae species? The development of fundamental studies focused on this morphogenetic route in the coming years could be the key to finding a higher number of points in common between these species, allowing the success of the SE of one species to positively affect the success of another. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

27 pages, 984 KiB

Open AccessReview

History, Phylogeny, Biodiversity, and New Computer-Based Tools for Efficient Micropropagation and Conservation of Pistachio (Pistacia spp.) Germplasm

by Esmaeil Nezami and Pedro P. Gallego

Plants 2023, 12(2), 323; https://doi.org/10.3390/plants12020323 - 10 Jan 2023

Cited by 2 | Viewed by 2615

Abstract

The word “pstk” [pistag], used in the ancient Persian language, is the linguistic root from which the current name “pistachio”, used worldwide, derives. The word pistachio is generally used to designate the plants and fruits of a single species: Pistacia vera L. Both [...] Read more.

The word “pstk” [pistag], used in the ancient Persian language, is the linguistic root from which the current name “pistachio”, used worldwide, derives. The word pistachio is generally used to designate the plants and fruits of a single species: Pistacia vera L. Both the plant and its fruits have been used by mankind for thousands of years, specifically the consumption of its fruits by Neanderthals has been dated to about 300,000 years ago. Native to southern Central Asia (including northern Afghanistan and northeastern Iran), its domestication and cultivation occurred about 3000 years ago in this region, spreading to the rest of the Mediterranean basin during the Middle Ages and finally being exported to America and Australia at the end of the 19th century. The edible pistachio is an excellent source of unsaturated fatty acids, carbohydrates, proteins, dietary fiber, vitamins, minerals and bioactive phenolic compounds that help promote human health through their antioxidant capacity and biological activities. The distribution and genetic diversity of wild and domesticated pistachios have been declining due to increasing population pressure and climatic changes, which have destroyed natural pistachio habitats, and the monoculture of selected cultivars. As a result, the current world pistachio industry relies mainly on a very small number of commercial cultivars and rootstocks. In this review we discuss and summarize the current status of: etymology, origin, domestication, taxonomy and phylogeny by molecular analysis (RAPID, RFLP, AFLP, SSR, ISSR, IRAP, eSSR), main characteristics and world production, germplasm biodiversity, main cultivars and rootstocks, current conservation strategies of both conventional propagation (seeds, cutting, and grafting), and non-conventional propagation methods (cryopreservation, slow growth storage, synthetic seed techniques and micropropagation) and the application of computational tools (Design of Experiments (DoE) and Machine Learning: Artificial Neural Networks, Fuzzy logic and Genetic Algorithms) to design efficient micropropagation protocols for the genus Pistacia. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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20 pages, 965 KiB

Open AccessReview

Choosing the Right Path for the Successful Storage of Seeds

by Magdalena Trusiak, Beata Patrycja Plitta-Michalak and Marcin Michalak

Plants 2023, 12(1), 72; https://doi.org/10.3390/plants12010072 - 23 Dec 2022

Cited by 4 | Viewed by 2017

Abstract

Seeds are the most commonly used source of storage material to preserve the genetic diversity of plants. However, prior to the deposition of seeds in gene banks, several questions need to be addressed. Here, we illustrate the scheme that can be used to [...] Read more.

Seeds are the most commonly used source of storage material to preserve the genetic diversity of plants. However, prior to the deposition of seeds in gene banks, several questions need to be addressed. Here, we illustrate the scheme that can be used to ensure that the most optimal conditions are identified to enable the long-term storage of seeds. The main questions that need to be answered pertain to the production of viable seeds by plants, the availability of proper protocols for dormancy alleviation and germination, seed tolerance to desiccation and cold storage at −20 °C. Finally, it is very important to fully understand the capability or lack thereof for seeds or their explants to tolerate cryogenic conditions. The proper storage regimes for orthodox, intermediate and recalcitrant seeds are discussed. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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10 pages, 429 KiB

Open AccessReview

The Role of γ-Aminobutyric Acid (GABA) in the Occurrence of Adventitious Roots and Somatic Embryos in Woody Plants

by Lu Pei, Yue Zhao, Xinru Shi, Rongrong Chen, Jiawei Yan, Xu Li, Zeping Jiang, Junhui Wang and Shengqing Shi

Plants 2022, 11(24), 3512; https://doi.org/10.3390/plants11243512 - 14 Dec 2022

Cited by 4 | Viewed by 1747

Abstract

The occurrence of adventitious roots and somatic embryos is a crucial step in micropropagation that frequently limits the application of this technique in woody plants. Recent studies demonstrated that they can be negatively or positively regulated with γ-aminobutyric acid (GABA), which is a [...] Read more.

The occurrence of adventitious roots and somatic embryos is a crucial step in micropropagation that frequently limits the application of this technique in woody plants. Recent studies demonstrated that they can be negatively or positively regulated with γ-aminobutyric acid (GABA), which is a four-carbon non-proteinous amino acid that not only acts as a main inhibitory neurotransmitter in mammals. It has been reported that GABA affects plant growth and their response to stress although its mode of action is still unclear. This review dealt with the effects of GABA on adventitious root formation and growth as well as on somatic embryogenesis. Furthermore, we focused on discussing the interaction of GABA with phytohormones, such as auxin, ethylene, abscisic acid, and gibberellin, as well as with the carbon and nitrogen metabolism during adventitious root development. We suggested that research on GABA will contribute to the application of micropropagation in the recalcitrant fruit and forest species. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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25 pages, 1449 KiB

Open AccessReview

Clonal Propagation of Walnuts (Juglans spp.): A Review on Evolution from Traditional Techniques to Application of Biotechnology

by Kourosh Vahdati, Rasoul Sadeghi-Majd, Adriana F. Sestras, Ricardo Julián Licea-Moreno, Augusto Peixe and Radu E. Sestras

Plants 2022, 11(22), 3040; https://doi.org/10.3390/plants11223040 - 10 Nov 2022

Cited by 10 | Viewed by 3201

Abstract

Walnuts (Juglans sp.) are allogamous species. Seed-derived plants are not always superior to the selected parent. Clonal propagation of selected stock plants is an essential requirement for the clonal fidelity of the descendants and to maintain their genetic structure. Selection of the [...] Read more.

Walnuts (Juglans sp.) are allogamous species. Seed-derived plants are not always superior to the selected parent. Clonal propagation of selected stock plants is an essential requirement for the clonal fidelity of the descendants and to maintain their genetic structure. Selection of the desired plant is realized only after reaching maturity, and characterizing and evaluating the performance of adult trees require a long time. Clonal propagation methods ensure proper transmission of characters to descendants and can be used effectively in breeding programs. The commercialization of a cultivar or rootstock depends on the success of vegetative propagation. Walnuts, like other tree species, are recalcitrant to conventional vegetative propagation methods and even non-conventional in vitro culture (micropropagation). Elucidation of factors determining the success of cloning of desired plants would contribute to understanding current limitations for most genotypes of Juglans. We outline the role of grafting and cuttings and stool layering, as well as in vitro culture on walnut multiplication. These techniques are, in practice, entirely different; nevertheless, they are affected by common factors. The incompatibility of stock-scion and the reduced ability of stem cuttings to root are the main bottlenecks for grafting and cutting, respectively. Genotype, age, and physiological status, reinvigoration or rejuvenation-treatment of donor plant, period of harvesting and processing of explants critically affect the results of methods followed. The in vitro culture technology is the most suitable for walnut cloning. This also has constraints that affect commercial propagation of most desired genotypes. We describe comprehensive results and synthesis in this review on the asexual reproduction of walnuts, providing a better comprehension of the limiting factors and the ways to overcome them, with direct implications on commercial propagation and the releasing of outstanding genotypes. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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Other

Jump to: Research, Review

12 pages, 3449 KiB

Open AccessBrief Report

The Influence of the Explant’s Type on the Performance of Synthetic Seeds of Blackberry (Rubus spp.)

by Luca Regni, Maurizio Micheli, Simona Lucia Facchin, Alberto Marco Del Pino, Cristian Silvestri and Primo Proietti

Plants 2024, 13(1), 32; https://doi.org/10.3390/plants13010032 - 21 Dec 2023

Viewed by 749

Abstract

In vitro propagation, also known as micropropagation, has become the most widely employed method for blackberry propagation, as it overcomes the limitations of the traditional asexual propagation methods (mainly layering and cutting). In this context, synthetic seed technology represents a strategy to enhance [...] Read more.

In vitro propagation, also known as micropropagation, has become the most widely employed method for blackberry propagation, as it overcomes the limitations of the traditional asexual propagation methods (mainly layering and cutting). In this context, synthetic seed technology represents a strategy to enhance the productivity of in vitro propagation and facilitates the exchange of plant materials between laboratories, contributing to germplasm conservation. This study aimed to identify the most suitable vegetative propagule for the encapsulation of blackberry. To this end, uninodal microcuttings (nodes) and the base of clumps were used to produce synthetic seeds for the cultivars Thornfree and Chester. Forty-five days after sowing, viability (percentage of green propagules without browning or necrosis), regeneration (percentage of propagules that sprouted and rooted simultaneously), number of shoots produced, shoot length, number of roots produced, root length, and the fresh and dry weights of the plantlets were measured. The results demonstrated that both considered propagules allowed us to obtain satisfactory regeneration rates. However, plantlets originating from the encapsulated clump’s base had more shoots and roots, resulting in greater fresh and dry weights than the plantlets derived from encapsulated nodes. Therefore, for achieving more robust plantlets and enhancing overall procedural efficiency, we recommend using the base of clumps as a propagule for blackberry encapsulation. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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7 pages, 1522 KiB

Open AccessBrief Report

Optimization of the In Vitro Proliferation of an Ancient Pear Tree Cultivar (‘Decana d’inverno’) through the Use of Neem Oil

by Luca Regni, Simona Lucia Facchin, Daniel Fernandes da Silva, Primo Proietti, Cristian Silvestri and Maurizio Micheli

Plants 2023, 12(8), 1593; https://doi.org/10.3390/plants12081593 - 10 Apr 2023

Cited by 1 | Viewed by 1355

Abstract

In vitro culture, ensuring rapid multiplication and production of plant material under aseptic conditions, represents an excellent tool for ex-situ conservation of tree species biodiversity and can be used for the conservation, among others, of endangered and rare crops. Among the Pyrus communis [...] Read more.

In vitro culture, ensuring rapid multiplication and production of plant material under aseptic conditions, represents an excellent tool for ex-situ conservation of tree species biodiversity and can be used for the conservation, among others, of endangered and rare crops. Among the Pyrus communis L. cultivars that have been abandoned over the years due to changed cultivation requirements, but which are still used today in breeding programs, there is the ‘Decana d’inverno’. Pear is generally considered a recalcitrant species for in vitro propagation due to weak multiplication rate, hyperhydricity, and susceptibility to phenolic oxidation. Therefore, the use of natural substances like neem oil (although little explored) represents one of the options to improve the in vitro plant’s tissue culture. In this context, the aim of the present work was to evaluate the effect of adding neem oil (0.1 and 0.5 m L L⁻¹) to the growth substrate in order to optimise the in vitro culture of the ancient pear tree cultivar ‘Decana d’inverno’. The neem oil addition resulted in an increase in the number of shoots produced especially at both concentrations used. On the contrary, an increase in length of proliferated shoots was observed only with the addition of 0.1 mL L⁻¹. The neem oil addition did not affect the explants viability, fresh and dry weights. Therefore, the present study demonstrated for the first time the possibility of using neem oil to optimise the in vitro culture of an ancient pear tree cultivar. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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