Response of Turf Bermudagrass Hybrids to Induced Drought Stress Under Controlled Environment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This research is well-done and needed to select the most drought tolerant varieties of bermudagrass for arid environments. I do not have any substantive edits, but suggest the author's review their figure legends to fully describe what is presented in each. At line 452, the sentence ended in and. and then had another ending on 453.

Author Response

This research is well-done and needed to select the most drought tolerant varieties of bermudagrass for arid environments. I do not have any substantive edits, but suggest the author's review their figure legends to fully describe what is presented in each. At line 452, the sentence ended in and. and then had another ending on 453.

Corrected the typo in the text. We appreciate for the comments.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have presented the results of an experiment to test the resistance to drought stress of different cultivars of bermudagrass hybrid. The topic is entirely related to the journal scope and is updated. The results are interesting, and in general terms, the manuscript is well-structured. Following, some comments have been added to improve the quality of their manuscript:

1. In the abstract, the authors should highlight some of the results of their test. For example, different grasses took time to recover from colour loss due to stress.
2. In the introduction, the authors must provide an adequate framework for turfgrass monitorization. Beyond the visual quality, recent papers have used additional metrics such as NDVI, soil moisture or canopy temperature and remote sensing. These should be included to complete the information provided in lines 68-70.

• (2021). Hybrid bermudagrass and tall fescue turfgrass irrigation in central California: II. Assessment of NDVI, CWSI, and canopy temperature dynamics. Agronomy, 11(9), 1733.
• (2022). Remote sensing devices as key methods in the advanced turfgrass phenotyping under different water regimes. Agricultural Water Management, 266, 107581.

3. In subsection 2.1, check the units of light intensity. If possible, include the minimum and maximum temperatures (not only the average ones) and the relative humidity in the greenhouse.
4. Subsection 2.3. Experimental design, response variables, and statistical analysis must be divided into multiple subsections.
5. It would be interesting to have a graphic, as shown in Figure 2, in which NDVI and NDRE are represented. Thus, information about the health status of the turfgrass will be provided to help differentiate between two genotypes with similar colour profiles.
6. The discussion section must be divided into multiple subsections.

Author Response

The authors have presented the results of an experiment to test the resistance to drought stress of different cultivars of bermudagrass hybrid. The topic is entirely related to the journal scope and is updated. The results are interesting, and in general terms, the manuscript is well-structured. Following, some comments have been added to improve the quality of their manuscript:

1. In the abstract, the authors should highlight some of the results of their test. For example, different grasses took time to recover from color loss due to stress.

We appreciate for the comment. We grouped the hybrids into three categories based on color lose and recovery. The sentence "A multivariate analysis grouped the hybrids into a drought tolerant with full recovery after re-watering, moderately tolerant, and susceptible to extended drought stress without recovery" reflect the summary of the results. 

2. In the introduction, the authors must provide an adequate framework for turfgrass monitorization. Beyond the visual quality, recent papers have used additional metrics such as NDVI, soil moisture or canopy temperature and remote sensing. These should be included to complete the information provided in lines 68-70.

• (2021). Hybrid bermudagrass and tall fescue turfgrass irrigation in central California: II. Assessment of NDVI, CWSI, and canopy temperature dynamics. Agronomy, 11(9), 1733.
• (2022). Remote sensing devices as key methods in the advanced turfgrass phenotyping under different water regimes. Agricultural Water Management, 266, 107581.

The introduction is revised based on the reviewer's comments using the reference information provided. We are grateful for the suggestions.

3. In subsection 2.1, check the units of light intensity. If possible, include the minimum and maximum temperatures (not only the average ones) and the relative humidity in the greenhouse.

The light intensity and the average temperature in the greenhouse for day and night were revised in the text for clarity. The temperature is set at these points on the control board to simulate the outside temperature of the area.  

4. Subsection 2.3. Experimental design, response variables, and statistical analysis must be divided into multiple subsections.

To reduce the sub-headings, we put these together and isolated them by paragraphs. Hope the reviewer will accept and the reader understands.

5. It would be interesting to have a graphic, as shown in Figure 2, in which NDVI and NDRE are represented. Thus, information about the health status of the turfgrass will be provided to help differentiate between two genotypes with similar color profiles.

Thank you for the comment. To present the results in abridged form, we used PCA (Fig. 5) to depict the visual and spectral reflectance indices/optical indices contribution to the overall performance of the hybrids. 

6. The discussion section must be divided into multiple subsections.

Thank you for the comment again. To keep the size of the manuscript optimum, we divided the points of discussion into paragraphs. We thought it gives a short and coherent information for the reader.

Reviewer 3 Report

Comments and Suggestions for Authors

1. Introduction Section:

The introduction should clearly state the novelty and innovation of this study. Additionally, it is recommended to include recent research progress on spectral applications in plants, particularly in drought resistance studies of Cynodon dactylon (Bermudagrass). This will better establish the scientific context and significance of your work.

 

2. Materials and Methods:

 

2.1 Plant materials: the description of plant materials is insufficient, please specify the variety of materials and their origin/source.

2.2 Experimental design : the description of control group treatment is missing.

 

3. Results Section:

 

3.1 I suggest add photographs showing materials with significant differences in drought resistance.

3.2 Add biomass data as a key indicator of plant growth status

3.3 Figure 2: Should indicate significant differences with proper statistical notation

3.4 Figure 3: Requires higher clarity and resolution

3.5 Figures 4 & 5: Need improvement in clarity and presentation

3.6 Figure 6A: Correct the mislabeled T_3 marker and remove textual explanations from the image

 

4. Discussion Section:

The current discussion is overly simplistic and merely reiterates results. The discussion should: compare your findings with existing literature, highlight both consistencies and discrepancies with previous reports, provide potential explanations for observed phenomena.

Comments on the Quality of English Language

No

Author Response

1. Introduction Section:

The introduction should clearly state the novelty and innovation of this study. Additionally, it is recommended to include recent research progress on spectral applications in plants, particularly in drought resistance studies of Cynodon dactylon (Bermudagrass). This will better establish the scientific context and significance of your work.

Recent reference information is included in the introduction part. Thank you for the comment.

2. Materials and Methods:

2.1 Plant materials: the description of plant materials is insufficient, please specify the variety of materials and their origin/source.

The origin and source of the hybrids and commercial checks were revised in the text. Grateful for your comments.

2.2 Experimental design: the description of control group treatment is missing.

The experiment is mostly comparison of germplasm for response to drought and T_0 is considered the control for the experiment.

3. Results Section:

3.1 I suggest add photographs showing materials with significant differences in drought resistance.

The pictures are submitted as a Supplementary with the revised manuscript.

3.2 Add biomass data as a key indicator of plant growth status

We did not collect biomass data. We were cutting every week at the same height but did not keep the clippings to measure the biomass. We did only the visual and spectral assessment.  We could make an inference using the 2D cover or NDVI but did not verify with actual biomass data and refrained from reporting it.

3.3 Figure 2: Should indicate significant differences with proper statistical notation

The Figure is modified and now include SE of means. As the inclusion of letters for statistical significance complicates the figure, we included a supplementary information for the statistical significance of the means.

3.4 Figure 3: Requires higher clarity and resolution

The clarity and resolution of Figure 3 is improved in the revised text.

3.5 Figures 4 & 5: Need improvement in clarity and presentation

To improve the clarity of Figures 4 and 5, we increased the fonts size

3.6 Figure 6A: Correct the mislabeled T_3 marker and remove textual explanations from the image

The Figure is corrected as suggested. Appreciated.

4. Discussion Section:

The current discussion is overly simplistic and merely reiterates results. The discussion should: compare your findings with existing literature, highlight both consistencies and discrepancies with previous reports, provide potential explanations for observed phenomena.

The discussion part is revised in relation to previous reports and explanations for differences. 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I have no additional comments. 

Author Response

Comment 1: I have no additional comments. 

Thanks for your professional review of our manuscript

Reviewer 3 Report

Comments and Suggestions for Authors

1. In the Materials and Methods section, details of the reagents, instruments, and software utilized, including the names of manufacturers and their corresponding locations, should be provided.

2.Figure 3 and 5 lack sufficient clarity. It is recommended to replace them with higher-resolution figures or redraw them for improved precision.

Author Response

Comment 1. In the Materials and Methods section, details of the reagents, instruments, and software utilized, including the names of manufacturers and their corresponding locations, should be provided.

We provided the details of the instruments and software information in the text as commented. We also added the process of color and quality estimation from the imaging in the M&M. We appreciate for the comment.

Comment 2. Figure 3 and 5 lack sufficient clarity. It is recommended to replace them with higher-resolution figures or redraw them for improved precision.

We increased the font size for Figure 3 for clarity. The image is already in high resolution. For Figure 5, we enlarged the components, so it is clearer than before now. 

We really appreciate for the professional comments and suggestions the reviewer gave us to improve the clarity of the manuscript

Author Response File: Author Response.pdf