Genotype-Environment Interaction: Trade-Offs between the Agronomic Performance and Stability of Dual-Purpose Sorghum (Sorghum bicolor L. Moench) Genotypes in Senegal

Round 1

Reviewer 1 Report

Title :

Genotype-environment interaction: trade-offs 2 between the agronomic performance and stability of 3 dual-purpose sorghum (Sorghum bicolor L. Moench) 4 genotypes in Senegal

Subject :

Authors selected for sorghum genotype adapted to verious environmental conditions based on the stability of grain yield.

Grain and biomass yields were the main parameters used to study the genotype-environmental factor interactions. Authors focused on the importance of the soil fertility and rainfall. The differences between the highest grain yields obtained with Nieleni and Fadda and the highest biomass yields with IS15401 and 439 SK5912 needs more explication in future analysis at level of biochemistry and molecular biology, as well as the unstability of some varieties in Fig 5 & 6, I propose to integrate that as perspective.

The paper is very useful for the breeding programs and in agronomy, personally, I appreciate the work. The paper is well written, figures and results well presented.

Author Response

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Reviewer 2 Report

The manuscript entitled “Genotype-environment interaction: trade-offs between the agronomic performance and stability of dual-purpose sorghum (Sorghum bicolor L. Moench) genotypes in Senegal” investigates the screening of sorghum genotypes in Senegal. The subject is a very important issue in agronomy. The authors should check the references and the order that are given. Also it is better to include in figure 3 and 4 the mean values of grain yield. The discussion should be more integrative. Therefore, I will recommend minor revision of the manuscript.

Author Response

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Reviewer 3 Report

This is an interesting and well-written paper describing the effects of genotype x environment interactions on 10 different sorghum lines grown in various locations in Senegal.  One particularly notable result is the fact that grain and biomass yields are affected to different degrees by each factor.  These results demonstrate that there is no single “best” choice for new sorghum genotypes to introduce into Senegalese breeding and growing programs, but rather that growers need to select specific lines depending on their local environment and desired trait.

 

The study design and statistical analyses all seem sound, so I do not have any major criticisms or concerns.  All of my comments are relatively minor and are related to points of clarification or grammatical corrections.  Below is a detailed list:

 

Minor Comments:

 

In the methods, I couldn’t quite tell exactly how many total plants were grown for each genotype in each location.  I saw that there were 40 hills = 40 plants x 7 rows = 280 plants per plot, but is this per genotype?  And were the 4 reps per plot of each genotype at each site?  If you could be more explicit about the exact sample sizes, it would help me to understand exactly how much statistical power was behind your analysis. Related to comment 1: out of all of the plants that were grown, did all survive and make it into the analysis? Or was the final sample size reduced because some plants died or didn’t produce seed, etc? In the first paragraph of the results, the authors mention that PC1 is strongly correlated with soil fertility and disease and PC2 is strongly correlated with rainfall, but after looking at the descriptions of each of the 6 environment groups and where they are in Figure 2, I don’t think I see the correlation. For example, group 1 is described as experience low overall rainfall, and so is group 6, but these 2 groups are at opposite extremes of the y-axis (i.e. PC2).  So how is it that PC2 is correlated with rainfall if it separates 2 environments that both have low rainfall? In Figures 3 and 4, it is hard for me to really see a difference in the 2000 kg.ha dots and the 3500 dots. Is it possible to make the gradient of size differences more extreme, so that it is possible to pick up this difference by eye more easily?  Also, in these figures, I think you should edit the x-axis labels to just say “Environment” and the y-axis labels to just say “Genotype”, since the means are not on the axis (rather they are reflected in the dot sizes).

 

Grammatical Corrections:

 

Lines 27-29 (First sentence of the abstract): Suggest changing to “Introducing sorghum (Sorghum bicolor L. Moench) genotypes into new environments is necessary for expanding the production of food and fuel, but these efforts are complicated by significant genotype x environment interactions that can reduce their effectiveness.

 

Line 37: move “Additive Main effect and Multiplicative Interaction” to come directly after the AMMI acronym (and not after the word analysis).

 

Line 45: change “but for highly specific” to “but only for highly specific”

 

Line 51: change “considered to be a plant of” to “well-adapted to”

 

Lines 69-71: suggest editing this sentence to say: “Understanding GxE interaction will help to (1) identify genotypes with a stable performance in fairly diverse growing conditions, and (2) match specific genotypes to specific environments.

 

Line 79: Delete “additive main effect and multiplicative interaction”, since you have already defined what AMMI stands for in the previous sentence.

 

Line 85: In my copy, for some reason the text that says “GxE interaction” is very small, so this formatting should be fixed to make it the same size as the rest of the sentence.

 

Line 88: what do you mean by a “mega-environment”? Should this say “meta” instead of “mega”?

 

Line 90: delete the “and” and replace with a comma.

 

Line 174: replace “poorly” with “little”

 

 

 

Author Response

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