Response of Bread Wheat Genotypes for Drought and Low Nitrogen Stress Tolerance
Round 1
Reviewer 1 Report
General:
This paper is nicely drafted about Genetic Characterization and Agronomic Evaluation of Drought Tolerance in Ten Egyptian Wheat Cultivars which helps in decision making processes of selecting lines for water management and crop response to drought stress
Abstract:
At the end, please highlight in 2-3 line about future implications of this work
Introduction: Nicely written introduction.
Line 60-61: Please cite some recent reviews on heat stress in wheat and associate drought due to heat stress.
For example: Yadav, M. R., Choudhary, M., Singh, J., Lal, M. K., Jha, P. K., Udawat, P., ... & Prasad, P. V. (2022). Impacts, Tolerance, Adaptation, and Mitigation of Heat Stress on Wheat under Changing Climates. International Journal of Molecular Sciences, 23(5), 2838.
Line 64-66: Crop physiological response are missing to show response during water stress.
physiological response to drought for other crops like soybean can be cited as:
Jha, P. K., Kumar, S. N., & Ines, A. V. (2018). Responses of soybean to water stress and supplemental irrigation in upper Indo-Gangetic plain: Field experiment and modeling approach. Field crops research, 219, 76-86.
Line 124: The hypothesis and objectives should be clearly defined. The future implications of this work can be added
Materials and methods:
Line 1234: Tukeys’ HSD help in mean separation among methods. If authors can, they should do so to strengthen statistical work.
Results: All table and figures should be in same font
PCA figures should have smaller fonts fro line. Figures are difficult to comprehend
Line 194: Line numbers and left of table should be fixed. Recommend same font in abele as in main text
Line 216: table 3 moved down same for table 4 and 6, 7. Please fix all the tables
Line 343: Please keep figure font also in Palatino Linotype as journal
Discussion:
I would suggest the authors to have a more supported discussion with references considering the main points below :
* The results that are like previous work
* Their results that are different and its implications for use in screening drought tolerant lines and related water management
* The limitations of their work and considerations when to apply the studied methodology and then the potential next steps or further investigation to address these limitations.
Conclusion: should include limitation and future implications.
References: Please double check the style of references and missing one
Author Response
17 May 2022
Ms Nickey Xu
Assistant Editor, Agronomy
Dear Ms Nickey Xu
Submission of a revised manuscript ID: agronomy-1711709
Thank you very much for the detailed and insightful comments and suggestions provided by the reviewers, which assisted in improving our manuscript (ID: agronomy-1711709) entitled “Response of bread wheat genotypes for drought and low nitrogen stress tolerance”.
We have provided the required revisions, which are indicated using highlighted text in the present submission. Below please find point-by-point responses to the comments and suggestions.
------------------------------------------------------------------------
Editor’s comments to Author:
Reviewing Editor
Comments to the Editor:
Comment 1: Please check that all references are relevant to the contents of the
manuscript.
Response 1: Thank you. Only revenant references are used in the paper.
Comment 2: Any revisions to the manuscript should be marked up using the “*Track Changes*” function if you are using MS Word/LaTeX, such that any changes can be easily viewed by the editors and reviewers.
Response 2: Agreed. Revisions are performed using track changes.
Comment 3: Please provide a *cover letter* to explain, point by point, the details of the revisions to the manuscript and your responses to the referees’ comments.
Response 3: Thank you. Provided.
Comment 4: If you found it impossible to address certain comments in the review reports, please include an explanation in your rebuttal.
Response 4: All suggested issues are attended.
Comment 5: The revised version will be sent to the editors and reviewers.
Response 5: Thank you.
Reviewer 1
Reviewer general comment: This paper is nicely drafted about Genetic Characterization and Agronomic Evaluation of Drought Tolerance in 10 South African Wheat Cultivars which helps in decision making processes of selecting lines for water management and crop response to drought stress.
Author response: Thank you very much for the constructive feedback.
Abstract
Comment 1: At the end, please highlight in 2-3 line about future implications of this work.
Response 1: Future implications have been added in lines 35 to 37.
Comment 2: Nicely written introduction.
Response 2: Thank you.
Comment 3: Line 60-61: Please cite some recent reviews on heat stress in wheat and associate drought due to heat stress.
For example: Yadav, M. R., Choudhary, M., Singh, J., Lal, M. K., Jha, P. K., Udawat, P., ... & Prasad, P. V. (2022). Impacts, Tolerance, Adaptation, and Mitigation of Heat Stress on Wheat under Changing Climates. International Journal of Molecular Sciences, 23(5), 2838.
Response 3: The two recent publications describing the impact of heat and drought stress have been included as suggested (lines 58 to 59).
Comment 4: Line 64-66: Crop physiological response are missing to show response during water stress.
Response 4: As advised, description on plant physiological responses are added (lines 66 to 76).
Comment 5: Line 124: The hypothesis and objectives should be clearly defined. The future implications of this work can be added
Response 5: Thank you. Hypothesis, objectives and future implications are added.
Materials and Methods
Comment 6: Line 1234: Tukeys’ HSD help in mean separation among methods. If authors can, they should do so to strengthen statistical work.
Response 6: Treatment means separation was conducted using the LSD procedure since some comparisons were made using check entries.
Results
Comment 7: Results: All table and figures should be in same font.
Response 7: Revised.
Comment 8: Line 194: Line numbers and left of table should be fixed. Recommend same font in abele as in main text.
Response 8: Revised.
Comment 9: Line 216: table 3 moved down same for table 4 and 6, 7. Please fix all the tables.
Response 9: Revised.
Comment 10: Line 343: Please keep figure font also in Palatino Linotype as journal.
Response 10: Modified to Palatino Linotype
Discussion
I would suggest the authors to have a more supported discussion with references considering the main points below:
Comment 11: The results that are like previous work.
Response 11: Each discussion section quoted suitable references.
Comment 12: Their results that are different and its implications for use in screening drought tolerant lines and related water management
Response 12: Previous relevant reports have been used to support the discussion in relation to breeding for drought and low nitrogen tolerance in wheat.
Comment 13: The limitations of their work and considerations when to apply the studied methodology and then the potential next steps or further investigation to address these limitations.
Response 13: Limitations and future implications are added (lines 644 to 648).
Conclusion
Comment 14: Conclusion: should include limitation and future implications.
Response 14: The limitations are captured in line 651-654, while future implications are provided in lines 666 to 670.
References
Comment 15: Please double check the style of references and missing one
Response 15: Thank you. The referencing style is amended and the list is prepared according to the Journal’s style.
Author Response File: 
Author Response.docx
Reviewer 2 Report
- The authors showed plenty of tables and figures in the manuscript and hard to follow. I suggest some tables can be present in SOM.
- Abstract how about the data of intermediate N? Is there any reseaons why you set only 50, 100, 200N for the experiment?
- The plant materials section (2.1) can be improved. More details need to provide related to the materials "The CIMMYT genotypes were selected based on their genetic variation for drought and heat stress tolerance", did you already know the tolerance data?
- The two local checks (SST 139 015 and SST 88) were selected for their ability to adapt under low N availability in the soil (DAFF., 2018). However, they ranked in the bottom five genotypes. How about checks sensitive and tolerence to N and drought stress?
- I did not see the greenhouse data in the results section.
- "Table 5 shows the mean values for agronomic traits of the top 10 and the bottom 5 genotypes evaluated under non-stressed (NS) and drought-stressed (DS) and three N levels. " For all traits, the top 10 and bottom 5 genotypes are identical?
- How many wheat plants in each plot?
- The authors used grain yeild in one place, while used GY in other, the same for other traits.
- To show the difference, I suggest to keep two decimal places for grain yeild data in the text.
- I suggest the results section need to be more condensed to show the key findings. Currently, it looks like a report.
- the format of references need to be improved.
Author Response
Reviewer 2
Comment 1: The authors showed plenty of tables and figures in the manuscript and hard to follow. I suggest some tables can be present in SOM.
Response 1: Given the involvement of several factors, we opted to use the current Table format. This will provide coherent and complete information for the readers.
Comment 2: Abstract how about the data of intermediate N? Is there any reasons why you set only 50, 100, 200N for the experiment?
Response 2: Thank you for the insight. The three N levels were selected as follows:
- 50 kg N/ha - low N (stressed) condition
- 100 kg N/ha - intermediate N condition
- 200 kg N/ha- recommended N level for wheat production in South Africa as provided by the Department of Agriculture, Forestry and Fishers of South Africa (DAFF, 2018).
Comment 3: The plant materials section (2.1) can be improved. More details need to provide related to the materials "The CIMMYT genotypes were selected based on their genetic variation for drought and heat stress tolerance", did you already know the tolerance data?
Response 3: The studied plant material was sourced from CIMMYT’s drought and heat stress nurseries. These lines were subjected to preliminary evaluations under South African condition and found to be drought tolerant.
Comment 4: The two local checks (SST 139 015 and SST 88) were selected for their ability to adapt under low N availability in the soil (DAFF., 2018). However, they ranked in the bottom five genotypes. How about checks sensitive and tolerance to N and drought stress?
Response 4: Local checks SST 015 and SST 88 were selected for their ability to adapt under low N stress. However, when tested for tolerance under drought and low N stress, they revealed relatively poor performance. The effect of drought stress and N deficiency might have contributed to their poor performance and reduced growth and development.
Comment 5: I did not see the greenhouse data in the results section.
Response 5: Data from the two growing conditions (greenhouse and field) were merged to compare the effect of the two water regimes and the three nitrogen levels for each agronomic trait for genotype selection.
Comment 6: "Table 5 shows the mean values for agronomic traits of the top 10 and the bottom 5 genotypes evaluated under non-stressed (NS) and drought-stressed (DS) and three N levels. " For all traits, the top 10 and bottom 5 genotypes are identical?
Response 6: The selected genotypes had outstanding performance across treatment combinations compared to other lines.
Comment 7: How many wheat plants in each plot?
Response 7: Field plots for each genotype were 1.5 m long rows with inter- and intra-row spacings of 45 and 15 cm. Each plot consisted of some 50 plants.
Comment 8: The authors used grain yield in one place, while used GY in other, the same for other traits.
Response 8: Thank you. We have used the abbreviations consistently where possible.
Comment 9: To show the difference, I suggest to keep two decimal places for grain yield data in the text.
Response 9: Agreed.
Comment 10: I suggest the results section need to be more condensed to show the key findings. Currently, it looks like a report.
Response 10: Palatino Linotype font fixed.
Comment 11: The format of references needs to be improved.
Response 11: The reference list has been formatted according to the Journal style.
Author Response File: Author Response.docx
