Application of Phenomics to Elucidate the Influence of Rootstocks on Drought Response of Tomato

Round 1

Reviewer 1 Report

To whom it may concern, 

Thanks for the invitation to review the current MS entitled 'Phenomics to Elucidate the Influence of Rootstocks on Drought Response of Tomato'. The current paper is interesting with some findings on clarifying the effects of rootstocks on tomato at water deficit using phenomics. 

The hypothesis of the current research was missing in the section of introduction. Both introduction and discussion sections can be improved by citing more-closely related publications. The size of Figure 2 and 3 can be decreased by removing the outsize frame so that the empty space can be removed as well. 

Author Response

General Comment: Thanks for the invitation to review the current MS entitled 'Phenomics to Elucidate the Influence of Rootstocks on Drought Response of Tomato'. The current paper is interesting with some findings on clarifying the effects of rootstocks on tomato at water deficit using phenomics

Response: We appreciate the reviewer's positive remarks on our work as well as the important suggestions to improve the manuscript's quality. We have revised the manuscript in response to the above-mentioned comment.

Comment #1: The hypothesis of the current research was missing in the section of introduction.

Response: Thanks for the valuable comment. We have inserted the hypothesis of the research work in Introduction in the revised manuscript.

Comment #2: Both introduction and discussion sections can be improved by citing more-closely related publications.

Response: As suggested by the reviewer, we have revised both the introduction and the discussion sections by with additional citations relevant to the topic. The changes are highlighted in track changes.

Comment #3: The size of Figure 2 and 3 can be decreased by removing the outsize frame so that the empty space can be removed as well.

Response: Figure 2 and 3 have been modified as per the suggestion.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors,

the paper "Phenomics to Elucidate the Influence of Rootstocks on Drought 2 Response of Tomato" is talking about an interesting topic, the improvement of plant features trough grafting without the involvement of genetic modification. The 62/RF grafting seems promising due to the low stomatal transpiration during the stress maintaining a low canopy temperature.

However few part need to be clarified as reported in the pdf.

Furthermore I suggest you to modify:

- invert the RGR and use that is using the dry biomass to exclude the water loss variable.

- the growth data are a mean of all the treatments? I did not see three dataset to compare the different treatment effect.

- Could you perform a statistics on WUI_AGR data?

- Modify the caption and remove "Graft combinations with common letters are not significantly different from each other."

Comments for author File: Comments.pdf

Author Response

General comments: The paper "Phenomics to Elucidate the Influence of Rootstocks on Drought Response of Tomato" is talking about an interesting topic, the improvement of plant features trough grafting without the involvement of genetic modification. The 62/RF grafting seems promising due to the low stomatal transpiration during the stress maintaining a low canopy temperature.

Response: Authors are grateful to the reviewer for his/her positive remarks on the work and providing valuable suggestion to improve the quality of paper.

Comment: Few part need to be clarified as reported in the pdf. Furthermore, I suggest you to modify.

Response: As suggested by the reviewer, we have modified the sentences in order to make more clear in the revised version of MS.

Comment #1 invert the RGR and use that is using the dry biomass to exclude the water loss variable.

Response: We used image features for predicting the biomass. Since these features are influenced by the water content and turgidity of leaves, we preferred fresh biomass over the dry biomass to calculate the RGR deviating from conventional approach. The purpose of study was to look for surrogate trait, which can accelerate phenotyping for key plant traits that can effectively differentiate plant response to water stress. For prediction of biomass we selected moderately and severely stressed plants. There was substantially high correlation between the fresh and dry biomass. Relevant statements and a supplementary figure have been included in the revised MS. We thank reviewer for this valuable comment.

Comment #2: the growth data are mean of all the treatments? I did not see three dataset to compare the different treatment effect.

Response: Yes, figures that depict effect of treatments include the bar graph derived from mean of each treatment.

Comment: Could you perform a statistics on WUI_AGR data?

Response: We carried out statistical analysis for WUI_AGR data as in supplementary Fig 1B. We avoided the shaded indicator for 0.95 CI in the Fig 1A (the trend graph) to maintain aesthetics of figure that was intended to provide the reader an idea about variation in the trend.

Comment: Modify the caption and remove "Graft combinations with common letters are not significantly different from each other."

Response: We have modified the caption of stress levels to make it more convenient to perceive for readers. Since the illustration has cluster of Figures to explain the observed genetic variation and significance of difference among the genotypes for each of the treatments, we retained the DMRT analysis letters over the bars even for WSM treatment (Moderate stress) where there was no significant difference in the Fig 2B.

 

Specific comments (as highlighted in PDF)

Line 1: Could be more complete using "Phenomic analyses"?

Response: Thanks for the suggestion; we revised it as ‘Application of Phenomics…”

Line 77: Which kind of stress?

Response: Abiotic stress including the drought stress

Line 92: … ‘are little information’ in place of ‘is meagre information’

Response: Corrected

Line 105: … ‘procured for’ replaced by ‘provided by’

Response: Corrected

Line 124: Why did you use ha if you are using small pots with a few amount of soil?

Response: As pointed out we converted the contents of nutrient elements in per kg soil.   

Line 149: Please be more clear!

Response: We have revised the statement to make it more clear.

Line 174-176: Please clarify

Response: As suggested, we revised the statement.

Line 190: Put the unit of measurement in square brackets after the formula.

Response: We made correction as per the suggestion.

Line 192-193: Please write as a formula with the appropriate tool.

Response: Formulae are written by using appropriate tool

Line 195: Why did you use tk and tj? They could confuse the reader.

You could use ‘start or end’ ‘1 or 2’

Response: We have modified it according to suggestions and used ‘t2’ for final day and ‘t1’ for initial day.

Line 247: Why don't you use 'WW' ?

Response: Modified as according to the suggestions and replaced S1 (WW), S2 (WSM) and S3 (WSS) to indicate well watered, moderate water stress ad severe water stress respectively.

Line 320: Treatments-this are not properly a treatments.

Response: Thanks for this comment. To avoid confusion, we have omitted “Treatments” and retained only the subtitles such as “Graft combination, Irrigation regime and Significance”

Line 325: why don't you adds also the data for S2 and S1 treatment?

Response: According to the suggestion, the data of S1 and S2 has been also added in the graph.

Line 328: This table at which treatment is it referring?

Response: Thanks for this comment. To avoid confusion, we have omitted “Treatments” and retained only the subtitles such as “Graft combination, Irrigation regime and Significance”

Line 334: ….severity²?

Response: corrected, It is reference citation …..severity [2].

Reviewer 3 Report

In this manuscript, a high throughput phenomics facility was used to assess the efficiency of tomato, grafted on the rootstocks of different genetic backgrounds, at different levels of moisture in the soil. The drought resistance of rootstocks was evaluated by measuring different factors，including Stomatal conductance, RWC, canopy temperature, and PSII efficiency and so on. They demonstrated the efficient use of a phenomics platform and develop a protocol to identify promising rootstock-scion combinations of tomato for optimization of water use. Overall, this is a good way to evaluate rootstocks. However, there are a lot of queries need to be addressed:

1.   There is a lack of necessary biological replicates in the experiments to verify the effects of water stress treatment on biomass and growth rates. Meanwhile, error lines are missing in FIG. 1 and FIG. 2A.

2.   Is there any difference in grafting affinity between 62 and various rootstocks? Grafting affinity between rootstock and scion can affect plant growth and biomass. It should be supplemented in the determined model.

Author Response

General comments: In this manuscript, a high throughput phenomics facility was used to assess the efficiency of tomato, grafted on the rootstocks of different genetic backgrounds, at different levels of moisture in the soil. The drought resistance of rootstocks was evaluated by measuring different factors including Stomatal conductance, RWC, canopy temperature, and PSII efficiency and so on. They demonstrated the efficient use of a phenomics platform and develop a protocol to identify promising rootstock-scion combinations of tomato for optimization of water use. Overall, this is a good way to evaluate rootstocks.

Response: We are thankful to the reviewer for his/her valuable remarks on the importance of the study and quality of the presentation. We are also grateful for the comments to improve the quality of the manuscript. The changes can be viewed in the track change option of the revised manuscript.

Comment #1: There is a lack of necessary biological replicates in the experiments to verify the effects of water stress treatment on biomass and growth rates. Meanwhile, error lines are missing in FIG. 1 and FIG. 2A.

Response: The experiment was conducted with four replicates in the plant phenomics facility which permits repeatability with sufficient level of certainty. Nonetheless, it is important to note that superiority of genotypes reported in this study aligns with previous reports. The current study largely focuses on phenomics protocol for differentiating the responses of rootstock combination. The error lines in FIG 1 are displayed in shaded part along the curve at CI of 0.95. Whereas the FIG2A intends to depict variation among the graft combination within the treatments.  Statistical significance among the treatment and also among the graft combination are depicted in FIG 2B.

Comment #2: Is there any difference in grafting affinity between 62 and various rootstocks? Grafting affinity between rootstock and scion can affect plant growth and biomass. It should be supplemented in the determined model.

Response: We agree with the reviewer’s comment on possible variation due to graft affinity. The rootstock and scion used in the experiment belong to the Solanum genus, species or the rootstocks used are closely related to the cultivated tomato. We did not observe any variation in grafting affinity between 62 and any of the rootstocks used in this experiment. Further, only the most successful and healthy graft combination for each of the rootstock were chosen for the experiment.

Round 2

Reviewer 2 Report

Dear authors,

thank you for the revision.

Few more suggestion:

-Why did you use moderate water stressed (WSM) instead of MWS and SWS?
-In the table 3  which treatment data mean did you used? WW, WSM o WSS?
-Why in the supplementary did you not calculate the WUI_AGR for WSS?

Author Response

dear Reviewer

we upload the response to comments.

best regards

Author Response File: Author Response.docx