Assessment of Grain Protein in Tropical Sorghum Accessions from the NPGS Germplasm Collection

Round 1

Reviewer 1 Report

The research of grain protein content assessment in tropical sorghum accessions from the NPGS germplasm collection is very useful for selecting paternal lines for breeding. The results and conclusions are well-written and clear for readers. While in sections "2.3. Protein content and statistical analysis" and "2.1. Germplasm" sections, both sections mentioned experimental design, but it is unclear to the reviewer why in 2018 and 2020, there is one block/replicate, whereas in 2022 thee are two reps.  Also, an experimental design section is needed. Other than above commons, the manuscript is ready to be published. 

Author Response

Thanks for the revision.  The limited number of seeds obtained from NPGS germplasm collection allow us to do one block in 2019 and 2020.  After we increased the seeds, we repeated the experiment with 2 blocks. We think is better have multiple year data rather than multiple blocks within a year. Clarification was include in the manuscript.

Experimental design section was included as suggest by the reviewer. 

Reviewer 2 Report

This manuscript analyzed the protein content of tropical sorghum accessions using NIR . The valve information about this manuscript is limited and less innovative . It is suggested that authors combine genotypes to study related phenotypes .

Author Response

Thanks for the revision.  We agree that include genotyping information could be useful to understand the genetic diversity of the germplasm, and the genetic relationship between accessions with high protein content. Nevertheless, the information presented here is valuable for sorghum breeding programs and its the first assessment of protein content for NPGS germplasm collection. We think the genotyping of this accessions could be do later using a more genetic diversity germplasm in order to do GWAS for protein content.  The main objective of our research was establish the NIR system to do the screening of NPGS tropical sorghum collections to identify high protein accessions. Certainly, a large screening of accessions could be combined with genotyping analysis.

Reviewer 3 Report

The aim of the refereed study is to assess the protein content of tropical sorghum genebank lots using NIR technology. A spectroscopic method for non-destructive analysis of sorghum grains was developed, calibrated, validated, and then analyzed 228 samples over several years.
Based on their results, 16 high-protein varieties were recommended for breeding programs.

The manuscript is well-structured and contains valuable information.

Just some suggestions:

The experimental design is described at the end of chapter 2.1, I suggest that this is shown in a figure.

Figures and tables should be placed in the text where they are referenced.

In the introduction and discussion, the protein composition of tropical sorghum should be highlighted better.

Author Response

Thanks for the revision. The figure for the experimental design was include in the new version. The figures and tables will be placed in the right place before publication. In the introduction we included information about the sorghum protein composition. 

Reviewer 4 Report

Your work and results are well worth sharing with the readers of "Agronomy."  However, your presentation needs some polishing.  Please see the attached file with suggested edits (all proposed changes highlighted in yellow).  My main concern is that you have very often misused the term "content" when you meant "concentration."  Content is a general term that applies in the following examples: the protein content of individual panicles varied between X and Y grams, or the maximum protein content for a single grain was Z mg.  Content is the concentration multiplied by the total mass of the object being studied.  The wording on the axes in Figures 1 and 2 also need to be corrected.  (I was unable to edit them.)

Comments for author File: Comments.pdf

Author Response

Thanks for the revision. All corrections and suggestion were included in the manuscript as suggest by the reviewer. 

Round 2

Reviewer 2 Report

The main purpose of this study was to establish a near infrared spectroscopy system to screen the high protein varieties of NPGS tropical sorghum germplasm. It is suggested that future studies should use large natural population combined with genotype information in order to extract more valuable information.