Assessing Drought Tolerance of Newly Developed Tissue-Cultured Canola Genotypes under Varying Irrigation Regimes

Round 1

Reviewer 1 Report

The article 'Assessing Drought Tolerance of Newly Developed Tissue Cultured Canola Genotypes under Varying Irrigation Regimes' contains interesting analyses that are important in view of the increasing frequency of drought phenomena in many places on earth. However, I have a few comments that need to be clarified:

Where did the soil parameters in table s2 come from? Did the authors do this research themselves? If so, please briefly outline the research methodology in the text. Or did the authors use the data from a source? If so, please provide a citation.

It is unclear how large the study field was and how many plants were in it. For a better understanding, it would be useful to add detailed experimental data and a diagram/map.

On line 120, the authors write that leaves were collected for further analysis. How many leaves were collected from each type of crop? Please provide more details.

Also missing is information on how many plants were measured, plant height (cm), number of branches per plant, number of pods per plant, number of seeds per pod, and seed yield? Without this information, verifying whether the experiment was well planned and the statistical analyses performed are reliable is impossible.

In Table 3, the authors report results for chlorophyll, proline, anthocyanin, glycine betaine, and total phenolic. However, it is not clear on what date and how many times the analyses were performed. Are the results included averages of multiple measurements? Please clarify this aspect in the methodology. The same comment also applies to Table 4.

Please check the notation of units throughout the manuscript and supplementary material and adapt it to the journal requirements.

In the discussion, the authors should relate their results more to previously published work. Are the results obtained in this work similar to previously conducted studies? If yes, why? If no, why not? There is a clear lack of discussion in this article. Please rewrite this section.

 

 

Author Response

Dear Editor,

We would like to thank you and the reviewers for the time and efforts devoted to our manuscript entitled “Assessing Drought Tolerance of Newly Developed Tissue Cultured Canola Genotypes under Varying Irrigation Regimes” (agronomy-2222417). We have revised the manuscript according to the comments and suggestions pointed out by the reviewers. We have addressed the comments of the reviewers in a point-by-point below in red color; in addition, we have highlighted all the associated changes made to the manuscript using track changes.

Yours sincerely,

Authors

Responses to Reviewers' Comments

Reviewer 1:

The article 'Assessing Drought Tolerance of Newly Developed Tissue Cultured Canola Genotypes under Varying Irrigation Regimes' contains interesting analyses that are important in view of the increasing frequency of drought phenomena in many places on earth. However, I have a few comments that need to be clarified:

Re: We would like to thank the Reviewer for his time dedicated to our manuscript and his positive assessment of our work.

Where did the soil parameters in table S2 come from? Did the authors do this research themselves? If so, please briefly outline the research methodology in the text. Or did the authors use the data from a source? If so, please provide a citation.

Re: More details and a reference have been added as requested, please see lines 98-101 in the revised version.

It is unclear how large the study field was and how many plants were in it. For a better understanding, it would be useful to add detailed experimental data and a diagram/map.

Re: Plot size, number of plants per plot and the area of the whole experiment have been added as requested (lines 116-119). Besides, a layout with detailed experimental data has been added in Figure (line 127).

On line 120, the authors write that leaves were collected for further analysis. How many leaves were collected from each type of crop? Please provide more details.

Re: Done as requested, the corresponding details have been added in lines 130-131.

Also missing is information on how many plants were measured, plant height (cm), number of branches per plant, number of pods per plant, number of seeds per pod, and seed yield? Without this information, verifying whether the experiment was well planned and the statistical analyses performed are reliable is impossible.

Re: More details have been added (lines 137-142)

In Table 3, the authors report results for chlorophyll, proline, anthocyanin, glycine betaine, and total phenolic. However, it is not clear on what date and how many times the analyses were performed. Are the results included averages of multiple measurements? Please clarify this aspect in the methodology. The same comment also applies to Table 4.

Re: We thank the reviewer for his remark. More details have been added as requested in lines 130-142. Ten plants of each plot were collected at 90 days after sowing in both seasons to determine the physiological parameters. The agronomic traits were recorded at the physiological maturity on 16th and 10th of April in the first and second seasons, respectively. the following agronomic traits were recorded from ten random plants per each plot.

Please check the notation of units throughout the manuscript and supplementary material and adapt it to the journal requirements.

Re: The units have been revised throughout the manuscript and supplementary material

In the discussion, the authors should relate their results more to previously published work. Are the results obtained in this work similar to previously conducted studies? If yes, why? If no, why not? There is a clear lack of discussion in this article. Please rewrite this section.

Re: The discussion has been revised and more information has been added as suggested (please see the discussion section).

Thanks so much for your review which contributed considerably to improve our manuscript.   

Reviewer 2 Report

The presented research describes the characterisation of ten canola genotypes in terms of their performance under different levels of drought stress.  The genotypes include commercial, exotic and tissue culture-selected genotypes. The presented data is a description of the genotypes’ performance based on some physiological and growth/yield variables and the correlation between these variables. The study aimed to identify drought tolerant and high yielding canola genotypes.  The presented data fall within the scope of general agricultural research and crop science as required by the journal of Agronomy. The presented research conveys descriptive data regarding the performance of canola genotypes to different levels of water deficit stress.  

                                             

Overall, the paper is written at an acceptable standard.  The authors delivered a dataset of good quality that logically outline the statistical performance of the genotypes by assessing various appropriate variables. The abstract reflects the content of the paper. The introduction section covers relevant information on the presented topic. The Material and Method section provides sufficient details in terms of experimental setup. Applicable variables known to be affected by water deficit stress, like proline levels etc. were chosen for assessment.  

 

The results are presented in a systematic and relevant manner. Presented figures are applicable and contribute to the overall theme of the research. Some concerns, Table 3 is described as: “Impact of …… of canola genotypes over two growing seasons.”, but values for the variables for the different genotypes for the two growth seasons are not presented?  Or were values somehow combined for the two seasons and compared to watered parental controls, this is unclear. And what level of drought stress does the values represent? In text: “Drought stress regimes displayed a substantial impact on all evaluated physiological parameters compared to well-watered conditions (Table 3)” but the table legend refer to two growth seasons?  The same for Table 4.  For Figure 1 and 2, also explain the statistical comparisons better. Why was a specific assessed parameter not compared across the different levels of stress within a genotype?  This is surely important to determine whether the levels of stress actually influence a genotype? 

 

The Discussion mostly cover the data gathered from the experimental work. However, no specific mention is made of the commercial genotypes that are considered drought tolerant. How/why were they classified as drought tolerance – at least give the reference for this. Does the current study support this assumption?  How did the tested genotypes compare to these commercial drought tolerant genotypes?  This need to be more specifically mentioned and discussed.  Also, the tissue culture generated genotypes were selected for salt tolerance, how does salt and drought tolerance link up?

 

Overall, the paper represents descriptive research data that analysed a number of canola genotype in terms of drought tolerance.    

 

Some minor grammatical issues and required sentence re-structuring are highlighted in red in the attached pdf file. 

 

 

Comments for author File: Comments.pdf

Author Response

Dear Editor,

We would like to thank you and the reviewers for the time and efforts devoted to our manuscript entitled “Assessing Drought Tolerance of Newly Developed Tissue Cultured Canola Genotypes under Varying Irrigation Regimes” (agronomy-2222417). We have revised the manuscript according to the comments and suggestions pointed out by the reviewers. We have addressed the comments of the reviewers in a point-by-point below in red color; in addition, we have highlighted all the associated changes made to the manuscript using track changes.

Yours sincerely,

Authors

Responses to Reviewers' Comments

Reviewer 2:

The presented research describes the characterisation of ten canola genotypes in terms of their performance under different levels of drought stress. The genotypes include commercial, exotic and tissue culture-selected genotypes. The presented data is a description of the genotypes’ performance based on some physiological and growth/yield variables and the correlation between these variables. The study aimed to identify drought tolerant and high yielding canola genotypes. The presented data fall within the scope of general agricultural research and crop science as required by the journal of Agronomy. The presented research conveys descriptive data regarding the performance of canola genotypes to different levels of water deficit stress. 

Overall, the paper is written at an acceptable standard. The authors delivered a dataset of good quality that logically outline the statistical performance of the genotypes by assessing various appropriate variables. The abstract reflects the content of the paper. The introduction section covers relevant information on the presented topic. The Material and Method section provides sufficient details in terms of experimental setup. Applicable variables known to be affected by water deficit stress, like proline levels etc. were chosen for assessment. 

Re: We would like to thank the Reviewer for his time dedicated to our manuscript and his positive assessment of our work.

The results are presented in a systematic and relevant manner. Presented figures are applicable and contribute to the overall theme of the research. Some concerns, Table 3 is described as: “Impact of …… of canola genotypes over two growing seasons.”, but values for the variables for the different genotypes for the two growing seasons are not presented?  Or were values somehow combined for the two seasons and compared to watered parental controls, this is unclear. And what level of drought stress does the values represent? In text: “Drought stress regimes displayed a substantial impact on all evaluated physiological parameters compared to well-watered conditions (Table 3)” but the table legend refer to two growth seasons?  The same for Table 4.  For Figure 1 and 2, also explain the statistical comparisons better. Why was a specific assessed parameter not compared across the different levels of stress within a genotype?  This is surely important to determine whether the levels of stress actually influence a genotype?

Re: The data presented in Table 3, Table 4, Figure 1, and Figure 2 are the average of two growing seasons. The pooled data of both seasons were analyzed, and the ANOVA analyses revealed that the season interaction with genotypes and irrigation regimes was not significant for twelve traits out of thirteen (Table S1). Accordingly, the measured traits were combined over the two seasons. More information has been added in the text to clarify this issue (159-161, 177, 181, 200, 204).

The main objective of the Figures of significant interaction (Figures 1 and 2) was to compare the assessed genotypes under different irrigation regimes. However, the main effects of irrigation levels on studied traits of all assessed genotypes were displayed in the first section of Tables 3 and 4. The presented reduction percentage in lines 163-165 are corresponding to severe drought stress.

The Discussion mostly cover the data gathered from the experimental work. However, no specific mention is made of the commercial genotypes that are considered drought tolerant. How/why were they classified as drought tolerance – at least give the reference for this. Does the current study support this assumption?  How did the tested genotypes compare to these commercial drought tolerant genotypes?  This need to be more specifically mentioned and discussed.  Also, the tissue culture generated genotypes were selected for salt tolerance, how does salt and drought tolerance link up?

Re: The discussion has been revised and more information has been added as suggested. The aspect of commercial cultivars has been discussed in lines 312-326, and the link between salt and drought tolerance has been discussed in lines 327-338.  

 Overall, the paper represents descriptive research data that analysed a number of canola genotype in terms of drought tolerance. Some minor grammatical issues and required sentence re-structuring are highlighted in red in the attached pdf file.

Re: All identified grammatical errors have been corrected.

Thanks so much for your review which contributed considerably to improve our manuscript. 

 Line 24: “tremendously”

Re: has been replaced by greatly (line 24)

Line 68: “leadsto”

Re: Corrected to “leads to” (line 68)

Line 75: double space

Re: Corrected (line 76)

Lines 105: Space

Re: space between “%” and “Etc” has been deleted throughout the manuscript  

Line 112: directly

Re: Has been deleted (118)

Line 123: Space

Re: space has been added (134)

Line 148: unclear to which genotypes the authors refer to here

Re: The reduction percentage for the main effect of severe drought on the evaluated genotypes

Line 154: total phenolic

Re: has been corrected to total phenolic content (line 170)

Lines 157: the

Re: has been deleted (line 172)

Lines 158: lowest physiological parameters

Re: has been corrected to “the lowest values for physiological parameters” (line 174)

Line 162: it is unclear which genotypes the authors include here??

Re: the first part of Tables 3 and 4 presents the main effect of irrigation regimes on evaluated traits for all assessed genotypes. The second part of Tables 3 and 4 present the main performance of the evaluated genotypes across the evaluated irrigation regimes.

Line 163: for each parameter assessed?

Re: Yes, the analysis was performed for each parameter

Line 168: Thus, comparisons were made between genotypes exposed to certain stress, and not within a genotype exposed to different levels of stress?

Re: Yes, the comparisons were made among genotypes exposed to different irrigation regimes.

 Line 174: in which genotypes? All?

Re: Yes, the reduction percentage for the main effect of severe drought on the evaluated genotypes

Line 181: yielded higher seeds

Re: Has been corrected to be “produced higher seed yield” (line 195)

Line 190: Thus same color bars refer, comparisons were made between genotypes at certain stress levels not in a genotype exposed to different stress levels?

Re: Yes, the same color bars corresponding to stress levels

Line 258: “predicted”

Re: Has been replaced by “expected” (274)

Line 263: transporting

Re: Has been replaced by “limiting its movement” (line 280)

Line 277: decisive

Re: has been replaced by “crucial” (line 294)