Water Relations and Physiological Response to Water Deficit of ‘Hass’ Avocado Grafted on Two Rootstocks Tolerant to R. necatrix

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript entitled " Water relations and physiological response to water deficit of ‘Hass’ avocado grafted on two rootstocks tolerant to R. necatrix." report the study of the response to water stress of ‘Hass’ avocado plants grafted on two R. necatrix tolerant rootstocks and to elucidate the morpho-physiological mechanisms involved. The results will be helpful to investigate the response mechanism of avocado to water stress.

The article would benefit from additional scions to further demonstrate the superiority of rootstocks in research. For the study on water stress resistance, it would be beneficial to include more measurement indexes to explore the underlying mechanisms. This study is the absence of demonstrating the interrelationships among the measured indicators. And the writing still requires significant improvement, particularly in the introduction and conclusion sections. Consequently, I believe that the current form of this article may not be suitable for publication in this journal.

 

Minor points:

(1) Add figures of the appearance changes of the samples under different treatments.

(2) Reduce the number of references by removing those not directly relevant to the manuscript.

(3) The figures should provide a clear explanation of the significance and usage of uppercase and lowercase letters.

Author Response

Comments and Suggestions for Authors:

The manuscript entitled " Water relations and physiological response to water deficit of ‘Hass’ avocado grafted on two rootstocks tolerant to R. necatrix." report the study of the response to water stress of ‘Hass’ avocado plants grafted on two R. necatrix tolerant rootstocks and to elucidate the morpho-physiological mechanisms involved. The results will be helpful to investigate the response mechanism of avocado to water stress.

#1. The article would benefit from additional scions to further demonstrate the superiority of rootstocks in research.

The avocado is a challenging species to cultivate due to its woody nature and the length of its intergenerational period. Moreover, the Frolich method of clonal propagation, which was employed in this trial, is a complex and time-consuming process. In this trial, the trees were four years old with a height of approximately one and a half meters. Two distinct rootstocks were grafted with the same scion for the comparative study. As previously noted by the reviewer, the utilization of supplementary scions to further demonstrate the superiority of rootstocks in research is undoubtedly of great interest and will be considered in future experiments. However, in the context of this particular study, it was difficult to take this approach due to the size of the plants employed and the spatial constraints within the greenhouse. Moreover, ‘Hass’ is, by far, the most extensively cultivated avocado variety worldwide.

#2. For the study on water stress resistance, it would be beneficial to include more measurement indexes to explore the underlying mechanisms.

We agree with the reviewer that the inclusion of additional parameters indicative of water stress resistance (e.g. proline accumulation, osmotic potential, root hydraulic conductivity, etc.) would have been beneficial and enhanced the work. However, additional measurements would have entailed more destructive procedures, thereby compromising the accuracy and reliability of the current data. Such an approach could have a detrimental effect on the plants, particularly given the short duration of the experiment (about 20 days, while avocado leaf development typically takes ~40 days) and the fact that these are 4-year-old woody plants growing in pots, whose growth potential may be diminished.

This study represents an initial investigation into the effect that the two rootstocks have on the response of avocado 'Hass' to water stress. The results obtained demonstrate that the rootstock plays a significant role in determining the water requirements of avocados and their ability to cope with water scarcity. In light of these findings, further comprehensive studies are necessary to elucidate the molecular basis and mechanisms underlying the rootstock-scion interaction. This is a current research focus of our group.

#3. And the writing still requires significant improvement, particularly in the introduction and conclusion sections.

The writing style of the introduction and conclusions has been revised for improvement.

#4. Consequently, I believe that the current form of this article may not be suitable for publication in this journal.

We hope that the revised manuscript meets with your approval for publication in Agronomy.

 

Minor points:

(1)        Add figures of the appearance changes of the samples under different treatments.

A supplementary figure (Supplementary Figure S1) showing the appearance of the plants from each rootstock on the different water stress levels has been included.

(2)        Reduce the number of references by removing those not directly relevant to the manuscript.

All references cited in the manuscript were appropriate for the research and supported the statements therein. However, in accordance with the reviewer's recommendation, we have carefully gone through the text and deleted the three that may be less relevant.

(3)        The figures should provide a clear explanation of the significance and usage of uppercase and lowercase letters.

Done as suggested by the reviewer.

Reviewer 2 Report

Comments and Suggestions for Authors

Where I have not marked comments in the publication in yellow, it means that I do not have them.

A very interesting experiment showing the influence of the rootstock and variable soil moisture on the  life processes of avocado plants. Abstract unacceptable - no value of the results obtained is provided. Especially those that differentiate the most important rootstock and  and substrate moisture levels.  The introduction raises relevant issues related to the experiment. The methodology does not provide the characteristics of the substrate, what constituted organic matter, whether it was peat or what dose of fertilizer was used per 1 liter of substrate. The methodology should specify in detail how to collect plant samples and randomly select leaves for measuring life processes, including: from what part of the plant, at what stage of development. Saying that there were seven to ten samples from each combination is far from enough. The beginning of the results marked in yellow in the publication should be transferred to the methodology because it illustrates the experimental setup and is not a description of the results. Two rootstocks with resistance to a selected soil disease were tested, and the plants were grown at three levels of substrate moisture, which is a sufficient number of combinations. The number of plants in a repetition of eight is also sufficient. Measurements were made with specialized equipment. The lack of plant growth and yield parameters raises doubts, which reduces the scientific value of the work.   The results in the first part should include numerical values or differences in results expressed as percentages, this will facilitate the interpretation of the results, which is sometimes difficult to interpret based on the attached figures. If the discussion compares the results of other authors of publications, they should be given in brackets. If other authors studied plants other than avocado, this should be noted in the text. Some parts of the discussion are a long repetition of the results, this should be shortened.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Sufficient level.

Author Response

Reviewer 2

Comments and Suggestions for Authors:

Where I have not marked comments in the publication in yellow, it means that I do not have them.

A very interesting experiment showing the influence of the rootstock and variable soil moisture on the life processes of avocado plants.

#1. Abstract unacceptable - no value of the results obtained is provided. Especially those that differentiate the most important rootstock and substrate moisture levels. The introduction raises relevant issues related to the experiment.

We thank the reviewer for his/her comments on our manuscript. We omitted the percentages due to the word 200-word limit of the abstract. In this revised manuscript, we have included the percentages of the most relevant variables, as recommended by the reviewer.

#2. The methodology does not provide the characteristics of the substrate, what constituted organic matter, whether it was peat or what dose of fertilizer was used per 1 liter of substrate.

The substrate specification and fertilizer dose per plant have been added to the materials and methods section.

#3. The methodology should specify in detail how to collect plant samples and randomly select leaves for measuring life processes, including: from what part of the plant, at what stage of development. Saying that there were seven to ten samples from each combination is far from enough.

Done as suggested by the reviewer. Pag. 4. Lines 177-178.

#4. The beginning of the results marked in yellow in the publication should be transferred to the methodology because it illustrates the experimental setup and is not a description of the results.

Done as suggested by the reviewer.

#5. Two rootstocks with resistance to a selected soil disease were tested, and the plants were grown at three levels of substrate moisture, which is a sufficient number of combinations. The number of plants in a repetition of eight is also sufficient. Measurements were made with specialized equipment. The lack of plant growth and yield parameters raises doubts, which reduces the scientific value of the work.

The plants used in this experiment were aged four years and cultivated in pots, having not yet entered the production phase. Therefore, it was not possible to quantify the fruit yield. Given the relatively short duration of the experiment (~20 days), we did not quantify the changes in plant size (height and trunk diameter) from the beginning to the end of the experiment to assess their temporal variation, as we expected this to be negligible. Instead, we measured total plant biomass and biomass partitioning in the control, WS1 and WS2 treatments, as indicators of the impact of water treatments on plant growth.

A field experiment is currently underway to evaluate the effect of rootstocks on the agronomic performance of the ‘Hass’ variety.

#6. The results in the first part should include numerical values or differences in results expressed as percentages, this will facilitate the interpretation of the results, which is sometimes difficult to interpret based on the attached figures.

Text has been amended according to reviewer suggestion.

#7. If the discussion compares the results of other authors of publications, they should be given in brackets. If other authors studied plants other than avocado, this should be noted in the text.

Text has been amended according to reviewer suggestion.

#8. Some parts of the discussion are a long repetition of the results, this should be shortened.

In accordance with the reviewer's recommendation, the text has been revised to eliminate the repetition of results in the discussion section.

Reviewer 3 Report

Comments and Suggestions for Authors

Comments

There is a need to review the manuscript for typographical errors. Examples include Line 39 (missing periods after "salinity"), Line 44 (adding the word "and" before "Australia"), and Line 63 (missing punctuation).

It is suggested to follow the standard order of the manuscript, with the Materials and Methods section placed before the Results and after the Discussion.

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Reviewer 3

Comments and Suggestions for Authors:

#1. There is a need to review the manuscript for typographical errors. Examples include Line 39 (missing periods after "salinity"), Line 44 (adding the word "and" before "Australia"), and Line 63 (missing punctuation).

The document has been carefully reviewed to avoid any typographical errors as suggested by the reviewer.

#2. It is suggested to follow the standard order of the manuscript, with the Materials and Methods section placed before the Results and after the Discussion.

Done as suggested by reviewer.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I appreciate the authors addressing all my comments. I have no more comments.