Root Traits Related with Drought and Phosphorus Tolerance in Common Bean (Phaseolus vulgaris L.)
Round 1
Reviewer 1 Report
In this study, the authors studied root traits related with drought and P tolerance in common bean plants grown in pots and field environments. Briefly, authors concluded that genotypes with greater taproot branching density and length, and high yield were identified as deeper-rooted and suited to water-stressed environments, while genotypes with fewer lateral branching density were identified as shallow-rooted and suited to low phosphorus availability environments and genotypes with the poor root system (lower taproot branching density and lower yield) were not adapted to either low P or drought stress. Please address the below-mentioned comments for further improvement.
- Please define the phosphorus (P) on the first appearance in the abstract and the text. Then, you can use its abbreviated form “P” throughout the text.
- Line 31, write the botanical name of common bean.
- Section 2.1., please explain how many pots were used? How many plants in one pot? And how the pots experiment was carried out with replication? This has not been mentioned anywhere in the methodology.
- There are many spacing and superscript issues throughout the text, e.g., 90, 105, 108, etc. Please carefully check the entire text and fix these issues.
- There are only one sub-headings in the results, and most of the parts are presented without headings. I recommend giving them headings for more clarity.
- In the figure legends, please fix the unit style (superscript).
- If it is a format-free submission, then it is ok. If no, please prepare the references according to the journal style.
Author Response
We thank the reviewer for the useful comments. We have, as much as possible, addressed the comments and where not, we have provided responses accordingly. Our responses are highlighted in yellow in the manuscript and the point-by-point response has been attached as a word file.
Author Response File: 
Author Response.doc
Reviewer 2 Report
Reviewer’s comments to the article:
Camilo et al.: Root traits related with drought and phosphorus tolerance in common bean (Phaseolus vulgaris L)
Dear Authors,
manuscript submitted is a very interesting and well-written study with significant novelties. Considering the following remarks:
1) Table 1: Considering the drought stress applied, indicate the water content of soil (v/v%) at field capacity and at permanent wilting point.
2) Fig. 1: Specify the irrigation ring used for pot stratification.
3) Line 98: Give the type of the TDR probe.
4) Line 104: Give the soil type of the experimental site, according to e.g. FAO-WRB (IUSS Working Group (2015): World Reference Base (WRB) for Soil Resources 2014, update 2015. International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports 106, FAO, Rome)
5) Line 127: “RCBD” abbreviation seems to be unnecessary.
6) Line 143: Field capacity water content is required here.
7) Line 152: Specify DAP here, as it is the first mention.
8) Line 153: Describe the procedure of root extraction from the soil in the pot experiment. This is important in respect to the accuracy of the root trait results.
9) Line 174: Add the diameter or volume of the root cores sampled.
10) Line 299: I miss a brief discussion on arbuscular mycorrhizal fungi (AMF). Legumes are known to be highly mycorrhizal-dependent plants. AMF is crucial for water and especially for P uptake of the legume host under limited conditions. Under low P supply, AMF play a key role in determining the plant vigour, production and grain yield. The root traits of the bean genotypes in the field experiment was obviously strongly depended on the presence of the native AMF strains in the filed soil, and their compatibility with different bean genotypes. Moreover, AMF colonization can highly influence root morphology, architecture and branching order. It is clear that the research did not focus on AMF, but I think that this important phenomena should be shortly discussed here.
11) Line 344–350: Drought is known to affect soil penetration resistance, and thus influence root development and branching.
Author Response
We would like to thank the reviewer for the useful comments. We have, as much as possible, addressed the comments and where not, we have provided responses accordingly. Our responses are highlighted in yellow in the manuscript. The point-by-point responses to the comments have been uploaded as a word file - see attachment.
Author Response File: Author Response.doc
Reviewer 3 Report
Authors explore different common bean genotypes in order to identify these that better adapt to drought and low P condition in the soil. They have correlate the tollerance to the above mentionated abiotic stress to taproot branching density and length, and yield. In this way they have associate 6 genotypes to water and low P stress tolerance.
Only some observations:
- I think that this is a good start point to better investigate the correlation between drought tolerance and taproot biomass. Do you think to do some experiments to this address?
- An other point, the genotypes identified should be observed in open field for not less 3 years period to verify the productive characters (yield, i.e.). In this way it could be interesting for farmers. What was the period of the observation?
However the overall manuscript is quite interesting and is well presented.
Best regards
Author Response
We thank the reviewer for the useful comments. The comments were mainly observational. We have, as much as possible, addressed the comments in the attached word file (see attachment).
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
Dear Authors,
Thank you for revising the MS according to the proposed comments. Notably, the MS quality has been improved. However, please address the below-mentioned minor issues.
- Please add a dot after “L” in the title.
- Please mention the crop name “common bean (Phaseolus vulgaris L.)” in the abstract's first introductory/objective lines.
- Why the font size and style are different from other figures? Please update the font size and style in fig 6.
Author Response
Dear Editor
We would like to thank the reviewer once more for the useful comments. We have, addressed the comments and provided responses accordingly. Our responses are in track changes in the manuscript. We have also attached a point-by-point response to the issues raised (please see attachment).
Sincerely
Julia Sibiya
Author Response File: Author Response.doc
