Seeds, Volume 1, Issue 4 (December 2022) – 10 articles

Seeds are a basic input for all crop production. Good seed is crucial for the global food and nutrition security, for rural development and farmers’ livelihoods and for all green value chains. What “good seed” is depends on individual farmer’s needs. The sustainable availability of seed and seed choice is thus an essential issue for every farmer. Farmers access seeds from multiple sources. Different seed systems have their strengths and vulnerabilities. With changing farming conditions around the world due to climate change, soil degradation and market demands, an analysis of possible disruptions and general future-proofing appears necessary. Such analysis also informs the kinds of support that different seed systems may need to be optimally resilient. Given the very limited studies on resilience of current seed systems, we performed a literature review on the opportunities and vulnerabilities of seed systems to identify possible resilience challenges. Seed system resilience in terms of future-proofing is closely linked with “seed security”, the secured access to preferred seeds by farmers. Such resilience depends on the functioning of each of the formal and farmers’ seed systems and how these two systems complement each other, particularly when one falters. In this paper, we describe the major characteristics of seed systems, analyze their strength and vulnerabilities, and describe support functions toward future-proofing them. Both the farmers’ and the formal seed systems are increasingly facing varying forms and degrees of sustainability challenges. These require various types of support. Farmers’ seed systems may find it hard to respond to radically changing conditions without support. Commercial formal seed systems are less vulnerable, as they generally are better equipped to respond to the (changing) needs of their customers. Commercial formal seed systems, however, only serve those farmers that are able and willing to pay for quality seeds. This immediately indicates a significant limitation. A common feature of both formal and farmers’ systems is their dependence on the continuous flow and capacity to use a diversity of plant genetic resources. In conclusion, no single seed system can be considered totally resilient and thus future-proof without specific external support. Full article

Common bean (Phaseolus vulgaris L.) is the most widespread legume in Croatia and its production is based on landraces of great morphological diversity. Landraces morphologically differ the most in the seed coat color and size. Because plant emergence and crop establishment represent the most sensitive stage in crop development, the aim of this study was to determine whether the seed coat color and seed size of Croatian common bean landraces affect the water absorption rate, seed germination, emergence and phenotypic characteristics of the seedlings. In this study seeds of four common bean landraces with different seed color and size, ‘Biser’ (white-colored, small-seeded), ‘Bijeli’ (white-colored, large-seeded), ‘Kornjača’ (dark-colored, small-seeded) and ‘Trešnjevac’ (dark-colored, large-seeded) were evaluated in three different experiments: (i) water uptake, (ii) seed germination and (iii) emergence and seedling phenotypic characterization. The results show that white-colored seeds have a higher absorption rate and release more electrolytes compared to dark-colored seeds of similar size (and weight). The germination results show that white-colored and smaller seeds germinate faster compared to dark-colored and large seeds. On the other hand, the white-colored landrace ‘Bijeli’ took the longest time to emerge, probably due to cell damage that occurred during the fast initial water absorption. Using multispectral imaging, chlorophyll fluorescence imaging and stomatal conductance analysis, the seedlings of the dark-colored and large-seeded landraces were found to contain more photosynthetic pigments and have higher light absorption. In contrast, seedlings of white-colored and large seeds have lower stomatal conductance and transpiration and higher photochemical efficiency (despite possible cell damage during water absorption and germination). Results suggest that dark-colored seeds could survive better under unfavorable soil conditions without absorbing water, swelling, emergence or molding than white-colored seeds. Despite all this, white-colored common bean landraces remain popular in human diets and are often grown on small-scale farms. Full article

Raising vegetable seedlings in pro trays is becoming an innovative approach to producing quality seedlings in horticulture. The present investigation was conducted to evaluate the effect of arbuscular mycorrhizal fungus (AMF) Glomus bagyarajii and potassium (K) solubilizing bacterium Frateuria aurantia singly and together in enhancing the growth of capsicum seedlings raised in pro trays under polyhouse conditions. Different growth parameters such as shoot and root length, total seedling length, stem diameter, dry weight of seedlings, biovolume index, plant strength, vigour index, macro and micronutrient uptake, mycorrhizal root colonization, and the population of F. aurantia in the root zone soil were monitored. Significantly higher shoot length, root length, stem diameter, and biovolume index were recorded in the treatments inoculated with G. bagyarajii alone, followed by F. aurantia alone. Most of the plant growth parameters were significantly less in the dual inoculated treatment with G. bagyarajii + F. aurantia compared to single inoculation with either of them. This brings out the negative influence of the two inoculants on each other leading to a reduced effect on plant growth. Full article

Seed traits are essential quantitative variables to assess seed quality and are also indicators of crop success. The World Vegetable Center Genebank in Arusha, Tanzania, has an important legume collection; however, there is limited information on seed traits per genotype, i.e., 1000-seed weight, the number of seeds per gram, germination percentage (GP), and mean germination time (MGT). In this study, 8 cowpea, 54 mungbean, and 15 soybean accessions were evaluated for the abovementioned parameters. A significant difference was observed among the genotypes of the selected legumes with respect to all the measured parameters. An intraspecific variation was also observed for the measured seed traits. The 1000-seed weight decreased with an increase in the number of seeds per gram. Unlike cowpea, the GP of mungbean and soybean accessions was significantly and negatively influenced by the number of seeds per 1 g. Hence, the smaller-sized seeds (with many seeds in 1 g) exhibited lower GP. It is concluded that the seed traits and initial quality among the selected legumes are strongly influenced by their genetic makeup. These results are useful to inform seed management, exchange, utilization, and have a high potential in breeding programs, and require further research attention. Full article

The in vivo germination course (15, 30, 45, and 60 days) of nine threatened local endemic plants of Crete (Greece) was studied due to conservation concerns and commercial interest in economic sectors. We used seeds directly collected from the wild sown in peat (Terrahum):perlite (1:1 v/v ratio)covered with coarse-grained vermiculite in a greenhouse mist bench with a substrate temperature of 19 ± 2 °C. The onset of in vivo germination was defined by the visible radicle protrusion (6th–9th day from sowing). After 60 days, 100% germination was observed for seeds of Campanula cretica, Dianthus fruticosus subsp. creticus, and Petromarula pinnata, followed by Draba cretica (91%) and Sanguisorba cretica (86%). Average–low germination capacity was observed for seeds of Calamintha cretica (26%), Lomelosia minoana subsp. minoana (38%), and Origanum microphyllum (23%), and very low capacity was observed for Onopordum bracteatum subsp. creticum (1.5%). After keeping seeds at 4–5 °C for three months, pre-treatments were performed (immersion in 50 or 250 ppm of gibberellic acid solution for 24 h) on three taxa with low germination capacity, thus resulting to the germination acceleration of Calamintha cretica seeds and increased germination capacity of Onopordum bracteatum subsp. creticum seeds. Apart from the facilitation of future species-specific conservation actions, the study showcases that the obtained results herein may permit an upgrade in the feasibility and readiness timescale assessments for the sustainable exploitation of studied taxa in different economic sectors. Full article

The in vitro propagation and ex situ conservation strategy provides new means for the conservation and mass propagation of economically and medicinally important plants. The present work aimed to observe the main characteristics of the in vitro propagation of Garcinia livingstonei from matured seed segments. Successful multiple shoots were induced on a woody plant (WP) medium supplemented with cytokinins. An average of 13.0 shoots per explant were grown from matured seed segments on a WP medium containing 15.0 µM BAP after 12 weeks of culture. The shoot elongation and multiplication were achieved using a repeated and periodic subculturing of shoot clumps in the same medium. The optimum in vitro rooting of shoots was obtained on the half-strength WP medium supplemented with IBA (5.0 µM). The regenerated plantlets were successfully transplanted to pots containing soil, sand, and farmyard manure (1:1:1) and were maintained in a greenhouse with a survival frequency was 80%. Full article

The phytosterol and tocopherol contents of almond kernel oil were evaluated in three almond cultivars, including the Spanish cultivar ‘Marcona’ and the French cultivars ‘Ferragnès’ and ‘Ferraduel’, grown under two different agro-climatic conditions, Zaragoza (Spain) and Meknès (Morocco). The analysis of variance showed significant effects of the genotype on kernel phytosterol content, Δ⁵-Avenasterol, Δ⁷-Campesterol, Stigmasterol and on the three tocopherol isomers. The location effect was significant on oil and kernel phytosterol contents, β-sitosterol,Δ⁵-avenasterol, Δ⁷-stigmastenol, Δ⁷-campesterol and α- and γ-tocopherol. The highest value of kernel and oil phytosterol contents were observed at Meknès (1.48 g kg⁻¹ and 2.54 g kg⁻¹, respectively), as compared to those obtained at Zaragoza (1.31 g kg⁻¹ and 2.54 g kg⁻¹, respectively).The highest values ofβ-sitosterol and Δ⁵-avenasterol were obtained at the Zaragoza location (81.93% and 10.55% of total phytosterols, respectively).The highest value of α-tocopherol was observed in the Morocco location (496 mg kg⁻¹ oil). These results indicate that under warm climate conditions in Morocco, the almond cultivars tend to accumulate more phytosterol and tocopherol. However, the significance of the genotype × location interaction on the phytosterol and tocopherol contentindicates that the magnitude of variation in these traits mainly depends on the genotype. Full article

Citrullus colocynthis, a native plant with potential uses as a feedstock for edible oil, biodiesel, and animal feed make it a potential cash crop. The importance of propagating this species under saline arid habitats necessitates understanding environmental factors affecting salinity and drought tolerance during the germination stage. Here, we assessed the impacts of seed collection time, the temperature of incubation on salinity, and drought tolerance during the seed germination stage of different accessions growing in the botanical garden of the University of Sharjah. No previous study assessed the interactive effects of these factors on the drought and salinity tolerance of this species. Three accessions (9, 10, and 13) differed in fruit and seed size and color, and germination behavior, and were selected from an earlier study. Seeds that matured in summer and winter on these accessions were treated with three salinities (0, 50, and 100 mM NaCl), and PEG levels (0, −0.3, and −0.6 MPa) and incubated at two temperatures (20/30 and 25/35 °C). The results showed significant effects of all factors (collection time, temperature, drought, and salinity) and their interactions on germination percentage. Seeds of C. colocynthis were very sensitive to salinity and drought stress, and the sensitivity depended on the time of seed collection, accession, and incubation temperature. The overall germination and tolerance to salinity and drought were significantly greater in seeds of accession 10, seeds that matured in summer, and seeds incubated at 25/35 °C. The germination in NaCl solutions was greater than in PEG solutions, indicating that seed germination was more sensitive to osmotic stress created by PEG than NaCl. Moreover, when transferred from NaCl, the recovery of ungerminated seeds was greater than in PEG solutions. This result indicates that the detrimental effect of salinity in C. colocynthis could be mainly attributed to osmotic rather than ion-toxicity effects. To adopt C. colocynthis as a cash crop or to restore degraded desert habitats, it is recommended to use seeds of drought- and salt-tolerant accessions (e.g., 10), especially those that mature in summer. Full article

This study investigates the effect of Gliding Arc Plasma Activated Water (GAPAW) technique on maize germination and growth variables. The effect of GAPAW was evaluated on corn texture, water absorption in Lab conditions, and the pathway Scanning electron microscopy (SEM) analysis of corn seeds was also carry out. Maize seeds were sown 150 m² and then watered with tap water and with GAPAW. Seed germination, maize growth and chlorophyll content were evaluated in field conditions in a complete randomized block design with four replicates using the Acid Tolerance Population (ATP) variety. Seed texture treated with 15 min of GAPAW making it darker than those of the control (tap water). Pathway SEM analysis showed no change for the 5 min-GAPAW-treated seeds compared to the control but at 15 min-GAPAW significant changes were observed. Germination was 100% at the 15 min-GAPAW compared to the other treatments (0 and 5 min). Stem length, leaf width, collar diameter, chlorophyll content and water uptake have higher values on plants watered with 15 min-GAPAW compared to others treatments. This application could highlight the germination properties of GAPAW in crop production. Full article

The Mongolian medicinal herb Herba Swertiae is a group of critically endangered medicinal herbs that are difficult to obtain from the wild. This is due to their low percentage of seed germination and difficult domestication. The aim of this study was to investigate the suitable germination conditions for enabling large-scale cultivation and improving the breeding efficiency of these herbs. We used the seeds of Lomatogonium rotatum (L.) Fries ex Nym, Gentianopsis barbata (Froel.) Ma., and Parnassis palustris L. to study their morphological characteristics and the required germination temperature and substrate. Results showed that there were aages outside the seed coats of all three Herba Swertiae collected from Hulunbuir, which had a binding effect on the primary root breaking through the seed coat to form seedlings. In addition, the seeds showed a significantly higher germination rate at 25 °C, and the percentage of seeds germinating in the mixed medium of soil and vermiculite at a 1:1 ratio was significantly higher than on filter paper. We conclude that the morphological characteristics of the seeds have great significance in promoting seed germination. Germination substrate, as an important medium, and temperature, as an important environmental condition, play crucial roles in plant seed germination. Full article