A Genome-Wide Association Study of Seed Morphology-Related Traits in Sorghum Mini-Core and Senegalese Lines

Round 1

Reviewer 1 Report

The manuscript presents a study of seed morphology in sorghum, analyzing eight key seed morphology traits across 245 accessions. The association of these traits with three diseases and the identification of SNPs via GWAS are also explored. However, the novelty is somewhat diminished given the authors’ previous published work using 162 Senegalese germplasms materials. To improve the manuscript, I recommend the following:

1. Could the authors do descriptive statistics (mean, maximum, minimum, standard deviation, and coefficient of variation et. al) for each seed morphology trait across the 245 accessions? It would aid in understanding the phenotypic distribution and assessing the adequacy of variability for GWAS.

2. It would be constructive to discuss whether any of the 100 candidate genes identified by GWAS have known functions related to seed morphology in sorghum, providing context to the genetic findings.

3. The potential influence of environmental conditions on seed morphology traits warrants examination. If data across different environments or years has been collected, this should be detailed, along with an analysis of how such factors may affect the traits in question.

4. Additional details regarding the protocols for sorghum disease detection should be elaborated in the materials and methods section to ensure clarity and reproducibility.

5. A comparison of the seed morphology data from the mini core collection lines and Senegal lines would be insightful. Differences, if any, between these two sets of lines and their implications could provide a deeper understanding of the genetic basis for morphological diversity.

6. The term 'LWR' is used without definition. For clarity, the full term 'Length to Width Ratio' should be provided at its first instance in the text.

Author Response

Dear Reviewer 1.

Thank you so much for your feedback. We revised as suggested as much as possible, and our answers to your questions are attached below.

Thank you again.

Author Response File: Author Response.pdf

Reviewer 2 Report

Sorghum (Sorghum bicolor L.) is one of the most crucial cereal crop and energy source globally. Its seed morphology is important for the yield and value. Using 115 sorghum mini core and 130 Senegalese germplasms, this study investigated 17 seed morphology-related traits including seed size, shape, and color et al. Statistical analyses explored potential associations between these traits and resistance to three major sorghum diseases: anthracnose, head smut, and downy mildew. Furthermore, authors conducted genome-wide association studies (GWAS) to identify  novel candidate defense genes. This work provides valuable information for seed size regulation in Sorghum and clues for the resistance to head smut by manipulating seed traits. For manuscript, the writing is clear and scientific for the audience. Even so, several minor issues are needed to be improved.

Minor issues:

1.     How authors obtained the data of resistance to head smut, anthracnose and downy mildew for the mini core Sorghum lines is not clear, which should be presented in the method part.

2.     For GWAS, some potential and important candidate genes identified should be presented and annotated in the result part but not only in the discussion part.

3.     Why the seed morphology associated with head smut but not anthracnose and downy mildew should be argued in the discussion part.

Author Response

Dear Reviewer 2.

Thank you so much for your feedback. We revised as suggested as much as possible, and our answers to your questions are attached below.

Thank you again.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thanks for the authors’ hard work to refine the manuscript. Given the significant improvement and the current state of the manuscript, I have no other comments.