Preliminary Exploration of Physiology and Genetic Basis Underlying High Yield in Indica–Japonica Hybrid Rice
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsXiaojuan Fan et al. submitted their study about “Preliminary exploration for physiology and genetics basis underlying high yield in indica-japonica hybrid rice”. Authors comprehensively explored the physiological mechanism of yield improvement in indica-japonica-hybrid rice, and used InDel genetic distance to study the genetic basis of heterosis, which will be helpful for future rice yield improvement.
Major points
1. Introduction: the purpose of work and importance of study should be clearly reflected in the introduction section.
2. Materials and methods: PCA and correlation statistical analysis should be clearly written.
3. Discussion: The discussion should be improved due to no much information available for interpretation of the results.
4. Conclusion: The conclusion should be incorporated in the manuscript based on the main findings of the study and provide guidelines for further research in the references.
5. Figures used in the study were not mentioned in the text at relevant places.
Some minor mistakes are highlighted in manuscript.
Comments for author File: 
Comments.pdf
minor mistake at few places must be improved.
Author Response
1#: Comments and Suggestions for Authors
Xiaojuan Fan et al. submitted their study about “Preliminary exploration for physiology and genetics basis underlying high yield in indica-japonica hybrid rice”. Authors comprehensively explored the physiological mechanism of yield improvement in indica-japonica-hybrid rice, and used InDel genetic distance to study the genetic basis of heterosis, which will be helpful for future rice yield improvement.
Author’s answer: thank you very much for your appreciation and careful review on our manuscript. That is your careful review that improve our manuscript a lot. The following questions were modified accordingly.
Major points
- Introduction: the purpose of work and importance of study should be clearly reflected in the introduction section.
Author’s answer: thanks for your comments, the introduction was refined making it more clearly to reflect our word.
- Materials and methods: PCA and correlation statistical analysis should be clearly written.
Author’s answer: Thanks for your comments, we have added the description of PCA analysis, and Duncan’s statistical analysis methods was used in this research for difference test.
- Discussion: The discussion should be improved due to no much information available for interpretation of the results.
Author’s answer: thanks for your comments, we have added the discussion based on our results hoping to improve the quality of this part.
- Conclusion: The conclusion should be incorporated in the manuscript based on the main findings of the study and provide guidelines for further research in the references.
Author’s answer: Thanks for your comments, we have added conclusion part accordingly.
- Figures used in the study were not mentioned in the text at relevant places.
Author’s answer: Thanks for your comments, we have added the citation of the figures in the text.
Some minor mistakes are highlighted in manuscript.
Author’s answer: Thanks for your comments, the mistakes were modified and highlighted in blue.
Reviewer 2 Report
Comments and Suggestions for AuthorsNicely written paper and sound science
Please add a conclusion section.
Give the significance of the study and do not repeat any results
As you authors mentioned line 395-398
yield increased please be specific to which yield. As authors measured paddy yield it should be clearly mentioned.
Usuauly in heterosis breeding the head rice yield is low due to grain molecular composition where loosely packed molecules are found.
As authors did not measure head rice yield, therefore, it is mandatory to mention paddy yield in the manuscript.
Also, authors should mention the limitation of the study in retrospect of head rice yield.
Comments on the Quality of English Language
Check minor mistakes
Author Response
2# Comments and Suggestions for Authors
Nicely written paper and sound science
Author’s answer: Thanks a lot for your recognition to our work, and we are extremely grateful to positive comments and suggestions. The manuscript was revised carefully according to your suggestions.
Please add a conclusion section.
Author’s answer: Thanks for your comments, the conclusion part was added.
Give the significance of the study and do not repeat any results.
Author’s answer: Thanks for your suggestion, we have added the significance accordingly.
As you authors mentioned line 395-398, yield increased please be specific to which yield. As authors measured paddy yield it should be clearly mentioned. Usually in heterosis breeding the head rice yield is low due to grain molecular composition where loosely packed molecules are found. As authors did not measure head rice yield, therefore, it is mandatory to mention paddy yield in the manuscript. Also, authors should mention the limitation of the study in retrospect of head rice yield.
Author’s answer: In China, total rice grain yield is most widely used for the yield determination. However, in fact, the head rice yield is low as you mentioned. We will also study how to increase head rice rate upon on heterosis breeding in our following research.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors1. Several researchers revealed that the indica–japonica hybrids have large sink and genetic source, capable of increasing the yield potential [6] Line 49-50.
2. L18-19 Yield components showed that z18 and y12 having the highest number of primary branches, spikelets and grains, so do grains yields. But, in Figure 3 of grain yield per plant, 1000 grain weight and biological yield are not significant among 04B, z12, LYPJ, z18 and y12. It means that the heterosis of indica–japonica hybrids are the same as indica hybrid, japonica hybrid and also conventional line. However, the graphs are not show statistical to compare among varieties.
3. Figure 2 Total leaf area of h818 (conventional line) is the same as Z18 and y12. Thus, in term of total leaf area compared between conventional line and indica-japonica hybrid is no heterosis.
4. All of Figures and Table are not cited in the results of the experiment.
5. All of Figure (1, 2, 3) are not show the statistical to compare among varieties (LSD or Duncant). So, it cannot explain that there are significant differences or not. Please revise all of the graphs.
6. In the results, the authors compared the percentage increase or decrease between indica-japonica hybrids with other varieties but it does not indicate whether the increase or decrease is a statistical difference or not. Therefore, the reporting of results should be revised by using statistics as an explanation tool.
7. It appears that only the heterosis at the root and leaf traits of indica-japonica hybrids are superior to other varieties. While other characteristics there aren't much difference.
8. In Figure 4, Scatter plotting showing the association among 35 materials based on PCA. So, what is means of 35 materials?
9. L365-367, This resulted in clear superiority and control advantages in single plant grain weight, single plant stem weight and single plant biological yield, and the yield advantage was significantly greater than that of other types of hybrid rice, but the harvest index decreased instead. Please consider the Figure 3, indica-japonica hybrids showed the same biological yield and grain yield with conventional, indica hybrid and japonica hybrid.
1 . L395-396, Our results showed that indica-japonica hybrid rice had stronger heterosis and higher yield potential. I won't believe this conclusion until I see the statistical results.
Comments on the Quality of English LanguageMinor edit of English.
Author Response
3# Comments and Suggestions for Authors
Author’s answer: Thank you very much and we are extremely grateful to your carefully review and constructive suggestions. The manuscript was revised carefully according to your suggestions.
- Several researchers revealed that the indica–japonica hybrids have large sink and genetic source, capable of increasing the yield potential [6] Line 49-50.
- L18-19 Yield components showed that z18 and y12 having the highest number of primary branches, spikelets and grains, so do grains yields. But, in Figure 3 of grain yield per plant, 1000 grain weight and biological yield are not significant among 04B, z12, LYPJ, z18 and y12. It means that the heterosis of indica–japonica hybrids are the same as indica hybrid, japonica hybrid and also conventional line. However, the graphs are not show statistical to compare among varieties.
Author’s answer: Thanks for your comments, we have added the Duncan’s statistical methods for significance analysis in M&M, and the significance of the figures were added accordingly. The indica hybrid and japonica hybrid varieties used in this research had good yield in agricultural production, which made these two varieties popular among rice farmers. And even if no significant differences were there between different rice varieties, 3%~5% increase in yield was also a very huge improvement for agricultural production. In our research, the grain yield of z18 was significantly higher than the indica hybrid and japonica hybrid varieties, however, though the increase of grain yield of y12 was not significant in compared with z12 and LYPJ, the increase (2.8% and 5.6%, in compared with z12 and LYPJ) was still very important.
- Figure 2 Total leaf area of h818 (conventional line) is the same as Z18 and y12. Thus, in term of total leaf area compared between conventional line and indica-japonica hybrid is no heterosis.
Author’s answer: Thanks for your comments, h818 is a rice restorer line, which belongs to large leaf rice style. In this study, no heterosis was observed between h818 and indica-japonica hybrid in terms of total leaf area, however, the leaf area was significantly larger in compared with another parent, or the average of two parents, which showed single parent advantage and middle parent advantage, but not double parent advantage.
- All of Figures and Table are not cited in the results of the experiment.
Author’s answer: Thanks for your comments, we have added the citation in the results.
- All of Figure (1, 2, 3) are not show the statistical to compare among varieties (LSD or Duncant). So, it cannot explain that there are significant differences or not. Please revise all of the graphs.
Author’s answer: Thanks for your comments, we have added the Duncan’s statistical methods for significance analysis in M&M, and the significance of the figures were revised accordingly.
- In the results, the authors compared the percentage increase or decrease between indica-japonica hybrids with other varieties but it does not indicate whether the increase or decrease is a statistical difference or not. Therefore, the reporting of results should be revised by using statistics as an explanation tool.
Author’s answer: Thank you very much for your comments, we have added the statistical significance of the results accordingly.
- It appears that only the heterosis at the root and leaf traits of indica-japonica hybrids are superior to other varieties. While other characteristics there aren't much difference.
Author’s answer: Thanks for your comments, we have added the statistical significance of the results accordingly. The hybrid rice varieties selected in this research have good appearance in the agricultural production. And it is the good growth characters that 04B and h818 were selected as parents for breeding. So even the difference was not that so much, the heterosis will still show huge potential for practical production.
- In Figure 4, Scatter plotting showing the association among 35 materials based on PCA. So, what is means of 35 materials?
Author’s answer: Thanks for your comments, 35 materials were the representative rice varieties that were selected for PCA analysis, and we have added the description of the details of the 35 materials in supplementary table 3.
- L365-367, This resulted in clear superiority and control advantages in single plant grain weight, single plant stem weight and single plant biological yield, and the yield advantage was significantly greater than that of other types of hybrid rice, but the harvest index decreased instead. Please consider the Figure 3, indica-japonica hybrids showed the same biological yield and grain yield with conventional, indica hybrid and japonica hybrid.
Author’s answer: Thank you very much for your comments, we noticed that we misused our data of biological yield, and thanks to your careful review. We have revised Figure 3, and the significance was added. And based on that zhe04A was a sterile line, so we delete the 1000-grain weight, grain yield and biological yield.
- L395-396, Our results showed that indica-japonica hybrid rice had stronger heterosis and higher yield potential. I won't believe this conclusion until I see the statistical results.
Author’s answer: Thanks for your comments, we have added the statistical significance of the results accordingly.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for Authorsaccept
