Exploring the Genetic and Morphological Variation and Disease Resistance in Local and Foreign Prunus persica (L.) Batsch Cultivars
, Georgios Pantelidis 1, Lefkothea Karapetsi 2,3, Konstantina Ziakou 1, Konstantinos Kazantzis 1, Panagiotis Madesis 2,3 and Thomas Thomidis 4Round 1
Reviewer 1 Report
Add peach latin to the title
Introduction
Add numerical data from the study results to the introduction section.
"Molecular, morphological and biochemical data should be evaluated together in determining genetic diversity between cultivars and genotypes." Include this sentence and relevant current references.
Where abbreviations are first used, full names should be written (RAPD, SSR, etc.)
Correlation between leaf and fruit characteristics is required.
It is a serious shortcoming that incompatibilities in local genotypes and cultivars have not been revealed.
Author Response
We thank the reviewer for contributing in the present study with his/her useful comments/suggestions. Please find below the reply to each one comment.
-Add peach latin to the title
Re: The peach latin name was included
- Introduction: Add numerical data from the study results to the introduction section.
Re: We understand that the reviewer wanted to say ‘Abstract’ section instead of ‘Introduction’ and numerical data were included
-Introduction: "Molecular, morphological and biochemical data should be evaluated together in determining genetic diversity between cultivars and genotypes." Include this sentence and relevant current references.
Re: It was included in the last paragraph
-Where abbreviations are first used, full names should be written (RAPD, SSR, etc.)
Re: It was corrected
- Correlation between leaf and fruit characteristics is required.
Re: Correlation analyses was included in a supplementary Table and discussed in a separate section.
- It is a serious shortcoming that incompatibilities in local genotypes and cultivars have not been revealed.
Based on the genetic variability of the studied peach cultivars, three different clusters were formed. The clusters that were formed mainly depend on the genetic similarity of the peach cultivars. The first cluster contained some of the foreign cultivars/ accessions along with the cultivars from the islands of Ikaria and Samos, that are geographically located far from the mainland of Greece. The second cluster contained cultivars/ accessions from Magnisia, Imathia which are located in the mainland and the island of Lesvos. Finally, the third cluster contained a mix of foreign cultivars along with cultivars/ accessions from Imathia, Kythira, Andros and one cultivar from Magnisia. Although, the ISSR markers were highly polymorphic, the low genetic variability revealed the high genetic similarity of the studied peach cultivars, which can be attributed to having common ancestors as this is not a native species in Greece and/or are propagated by cuttings and also to the continuous transportation of people and goods (tree clones and more) between the mainland and the numerous islands of Greece.
Reviewer 2 Report
Overall, this study on local peach germplasm in Greece is fascinating and offers insightful information on genetic and morphological heterogeneity as well as disease susceptibility. In their detailed discussion of their procedures and findings, the authors have included both qualitative and quantitative assessments. Here are some more detailed remarks:
1. The study could benefit from additional details on the prospection process, such as how the 32 peach cultivars/accessions were selected and whether there were any criteria or considerations involved in the selection process.
2. It would be helpful to clarify how the local cultivars/accessions were separated from foreign cultivars in the 8 out of 42 leaf and fruit qualitative and quantitative phenotypic traits. Were there specific traits that showed more variation between local and foreign cultivars?
3. The authors have noted that the genetic diversity among the peach cultivars was moderate to low, and three distinct clusters were formed. However, it would be interesting to explore the possible reasons for this limited genetic diversity, such as historical factors or human selection.
4. The use of ISSR markers in genetic characterization is an interesting choice. It would be helpful if the authors could explain why they selected these markers and how they compared to other available marker systems.
5. In the MRA analysis, the authors identified several markers that were significantly correlated with fruits’ traits. It would be helpful if the authors could provide more details on the specific traits and markers involved, and how these findings might be useful for breeding programs.
6. Overall, the study provides valuable insights into local peach germplasm in Greece and highlights the importance of preserving and utilizing such resources for genetic improvement. The authors have presented their findings clearly and comprehensively, and their results could be of interest to researchers and breeders working on peach cultivars.
Author Response
We thank the reviewer for contributing in the present study with his/her useful comments/suggestions. Please find below the reply to each one comment.
- The study could benefit from additional details on the prospection process, such as how the 32 peach cultivars/accessions were selected and whether there were any criteria or considerations involved in the selection process.
Re: In lines 123-132 it was written: A total of 32 peach cultivars/ accessions were selected from farms, home yards or already maintained at the Department of Deciduous Fruit Trees in Naoussa. A selection was considered when there was information that it was grown for at least two generations in the region, yet the genotypes selected in Imathia may have been spots from old foreign cultivars. Therefore, 13 old foreign cultivars were also studied for comparison.
- It would be helpful to clarify how the local cultivars/accessions were separated from foreign cultivars in the 8 out of 42 leaf and fruit qualitative and quantitative phenotypic traits. Were there specific traits that showed more variation between local and foreign cultivars?
Re: Differences between local and foreign cvs are presented in figure 2 and are discussed in lines 311-314, 324-330, 353-359, 390-391. If we have misunderstood something, please let us know.
- The authors have noted that the genetic diversity among the peach cultivars was moderate to low, and three distinct clusters were formed. However, it would be interesting to explore the possible reasons for this limited genetic diversity, such as historical factors or human selection.
Re: The moderate to low genetic diversity is mainly due to the high genetic similarity of the peach cultivars included in our study. The low genetic diversity among the plant material that originated from different areas of Greece suggest, that these plants either have common ancestors and/or are propagated by cuttings and not seeds. We agree that it would be very interesting to explore the possible reasons for this limited genetic diversity, but the lack of official historical factors is hindering. We can only hypothesize that human selection has been the main factor that has mainly contributed to the selection of specific cultivars with desirable fruit characteristics and the transfer of these cultivars, across the mainland and the islands of Greece.
- The use of ISSR markers in genetic characterization is an interesting choice. It would be helpful if the authors could explain why they selected these markers and how they compared to other available marker systems.
Re: Compared to other categories of molecular markers, we selected the ISSR markers, because they are very simple to use, as they do not require prior sequence information, like SSR or SNP markers, and can result with high number of polymorphisms, especially for studying closely related individuals such as the peach cultivars in our study.
- In the MRA analysis, the authors identified several markers that were significantly correlated with fruits’ traits. It would be helpful if the authors could provide more details on the specific traits and markers involved, and how these findings might be useful for breeding programs.
Re: Two markers (UBC841_750 and UBC841_1620) were associated with RD (Ripening date), UBC841_750 showed a strongly negative and statistically significant correlation (beta coefficient = -0.535, p = 0.002) while UBC841_1620 showing average correlation. One marker was associated with FFW (Fresh Fruit Weight) (UBC834_1030) showing average correlation. A total of three markers were identified for SSC (Soluble Solid content) (UBC841_390, UBC827_1190, and UBC834_550), showing average correlation. For TA (Titratable acidity) a total of four markers were identified (UBC823_650, UBC841_1050, UBC841_450, and UBC827_600), UBC823_650 showed a strongly positive and statistically significant correlation (beta coefficient = 0.738, p = 0.002) while the other markers showed average correlation. Finally, three markers (UBC823_650, UBC841_350, and UBC841_1050) were identified for RI (Ripening index), UBC823_650 showed a strongly negative and statistically significant correlation (beta coefficient = -0.637, p < 0.001) while the others showing average correlation. All these markers that were found to have a strong or average positive and/or negative correlation with important fruit characteristics, can be utilized in breeding programs for the fast and reliable screening of seedlings, a process that is time consuming, without waiting until the trees produce the fruits and check for the desirable characteristics.
Reviewer 3 Report
The manuscript meets the required criteria for publication on the journal.
Specifically:
- The background of the work is well described
- All sections are clear and legible
- The results give insight into the genetic and phenotypic variability in leaf and fruit traits and disease resistance in local peach cultivars/accessions
Some English expressions could be improved.
Author Response
We thank the reviewer for his/ her positive remarks.
Round 2
Reviewer 1 Report
Ms is ready for publication.
Reviewer 2 Report
All the comments were properly addressed.
