The Current Status and Prospects of Molecular Marker Applications in Head Cabbage (Brassica oleracea var. capitata L.): A Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Summary

The authors present an interesting narrative review that aims to provide a useful resource for allele mining in cabbage crops, identifying valuable genetic loci for breeding strategies. The topic is relevant and timely; however, several sections require improvement to enhance clarity, scientific depth, and practical utility for breeders. The manuscript should be revised accordingly before it can be considered for publication.

Title

After the Latin name of the species, please include the author abbreviation: B. oleracea L.

Abstract

The abstract is too general and lacks specificity. The genetic markers or candidate loci identified as relevant to cabbage breeding should be specified. Furthermore, authors should indicate the key agronomic or morphological traits (e.g., yield, disease resistance, head formation, stress tolerance) that are most commonly targeted in cabbage improvement programs.

Introduction

• The MADS-box gene family should be explicitly discussed, as allelic diversity in these genes is known to distinguish cauliflower and broccoli (characterized by hypertrophic inflorescences) from other B. oleracea L. crops. I strongly recommend including the following references: https://doi.org/10.3390/agriculture11070622; https://doi.org/10.1186/s12870-019-1717-y

This section should also introduce the main breeding strategies used for cabbage, presenting a brief overview of traditional breeding programs (e.g., number of experimental lines required to generate a stable hybrid with a target trait). Authors should also compare traditional breeding strategies with marker-assisted selection (MAS) and genomic selection (GS) approaches.

Mention of participatory breeding programs and how these can enhance efficiency and farmer adoption.

Tables

• Tables 2 and 3 are overly general and should be restructured for clarity and utility.
• I strongly recommend creating separate, topic-specific tables (e.g., disease resistance, abiotic stress tolerance, yield/quality traits). Each table should include: Candidate gene/locus name; Chromosomal location; Encoded enzyme or product; NCBI Gene ID or GenBank accession number; Associated trait or phenotype

This improvement is mandatory to make the review a practical and valuable reference for breeders.

Conclusion

• The conclusion should summarize the most commonly used molecular markers currently applied in cabbage breeding programs.
• Highlight how allele mining and genomic tools are shaping the future of B. oleracea L. breeding strategies.

 

Author Response

Dear Reviewer,

We would like to express our sincere gratitude for your thorough assessment of our manuscript and for the insightful comments you provided. Your feedback was extremely helpful in strengthening the arguments, clarifying the presentation, and enhancing the overall quality of our paper.

We have carefully considered all your suggestions and have revised the manuscript accordingly. Thank you once again for your valuable contribution to our research.

The authors would like to extend their special appreciation to the reviewers for their insightful suggestions and for providing relevant literature references.

 

Comments 1: After the Latin name of the species, please include the author abbreviation: B. oleracea L.

Response 1: Kindly thank you for the commentary. We include the author abbreviation to the subspecies title for correctness of the description.

 

Comments 2: The abstract is too general and lacks specificity. The genetic markers or candidate loci identified as relevant to cabbage breeding should be specified. Furthermore, authors should indicate the key agronomic or morphological traits (e.g., yield, disease resistance, head formation, stress tolerance) that are most commonly targeted in cabbage improvement programs  

Response 2: Thank you for your valuable comments. The abstract has been revised to specify the traits, their governing genes, and associated markers. For precision, the abstract now includes only the description of traits directly addressed in this review.

 

Comments 3: The MADS-box gene family should be explicitly discussed, as allelic diversity in these genes is known to distinguish cauliflower and broccoli (characterized by hypertrophic inflorescences) from other B. oleracea L. crops. I strongly recommend including the following references.

Response 3: Thank you for commentary. We have incorporated a description of the MADS-box gene family into the Introduction as a prime example of genes underlying the differentiation of B. oleracea subspecies for a spectrum of traits.

 

Comments 4: This section should also introduce the main breeding strategies used for cabbage, presenting a brief overview of traditional breeding programs (e.g., number of experimental lines required to generate a stable hybrid with a target trait). Authors should also compare traditional breeding strategies with marker-assisted selection (MAS) and genomic selection (GS) approaches. Mention of participatory breeding programs and how these can enhance efficiency and farmer adoption.

Response 4: We thank you for highlighting this issue. We have added descriptions of classic head cabbage breeding approaches, Marker-Assisted Selection,and Genomic Selection, and some modern techniques applicable to cabbage breeding and genetic research.

 

Comments 5: Tables 2 and 3 are overly general and should be restructured for clarity and utility. I strongly recommend creating separate, topic-specific tables (e.g., disease resistance, abiotic stress tolerance, yield/quality traits). Each table should include: Candidate gene/locus name; Chromosomal location; Encoded enzyme or product; NCBI Gene ID or GenBank accession number; Associated trait or phenotype This improvement is mandatory to make the review a practical and valuable reference for breeders.

Response 5: Thank you kindly. We have compiled several new tables detailing molecular markers for four trait groups. For user convenience, each table is structured with columns specifying the governing gene, genomic position (chromosome), transcript product, and GenBank accession number. This layout significantly improves the utility of the data for researchers.

 

Comments 6: The conclusion should summarize the most commonly used molecular markers currently applied in cabbage breeding programs.

Response 6: Thank you for commentary. The Conclusion has been restructured to incorporate a description of the most widely employed markers associated with the examined traits.

 

Comments 7: Highlight how allele mining and genomic tools are shaping the future of B. oleracea L. breeding strategies.

Response 7: Thank you for highlighting this issue. A description of the allele mining approach for the study of cabbage (Brassica oleracea var. capitata) genetics is provided. Additionally, genomic selection methodologies are described as an extension of marker-assisted selection frameworks.

 

Thank you for your time and careful review of our manuscript.

Best regards

Reviewer 2 Report

Comments and Suggestions for Authors

In this review ‘The Current Status and Prospects of Molecular Marker Applications in Head Cabbage (Brassica oleracea var. capitata): a review’, the authors provide a comprehensive overview of molecular marker applications in head cabbage breeding. The manuscript covers a wide range of traits and breeding objectives, supported by extensive references. However, several important corrections and improvements are needed to enhance the accuracy, clarity, and organization of the content.

1. Line 95: The candidate gene for *Ms-cd1* is incorrectly given as Bol0357N3. Although the mapping interval reported by Liang et al. is correct, the actual gene was recently identified by Han et al. (2023). Please update the text accordingly.

Reference:

Han F, Yuan K, Sun W, et al. A natural mutation in the promoter of *Ms-cd1* causes dominant male sterility in Brassica oleracea. Nature Communications. 2023;14(1):6212.

 

2. Line 110: The author name “Chen C. et al.” should be simplified to “Chen et al.” for consistency with standard citation style. Please check and revise in the whole manuscript.

 

3. Section 2.1 (DGMS/RGMS): The review should include additional recessive genic male sterility genes beyond ms3, such as BoCYP704B1, for which molecular markers have also been developed.

Reference:

Ji J, Yang L, Fang Z, et al. Recessive male sterility in cabbage (Brassica oleracea var. capitata) caused by loss of function of BoCYP704B1 due to the insertion of an LTR-retrotransposon. Theoretical and Applied Genetics. 2017;130(7):1441–1451.

 

4. Structural Reorganization: The current grouping of certain traits under inappropriate sections affects the logical flow of the manuscript. Specifically: “Petal color” should not be placed under “Hybrid Breeding”, “Leaf color” and “Cabbage waxiness” are not abiotic stress traits and should be reclassified, possibly under a new section such as “Morphological Traits.”

 

5. Section 4.4: The heading “Resistance to downy mildew” is inconsistent with the format of other subheadings (e.g., “Fusarium wilt resistance,” “Black rot resistance”). Please revise for consistency.

 

6. Line 214: “Xing L. I. et al.” should be “Li et al.” Line 27: “Li Zhi Yuan et al.” should be “Li et al.”

Please ensure all author names follow a consistent format (e.g., “Surname et al.”).

 

7. Line 282: The statement that “F₁ hybrids display an intermediate phenotype for this trait” is incorrect. For example, when a white-petaled line is crossed with a yellow-petaled line, the F₁ typically exhibits white petals, not an intermediate color. Please correct this misrepresentation.

 

8. Lines 284–285: The *cpc-1* locus (candidate gene BoCCD4) is involved in carotenoid degradation, not biosynthesis. This should be clarified to avoid misunderstanding.

 

9. Lines 356–367: The section on yellow leaf mutants should include recent findings on *BoYgl-2*, a PPR protein involved in chloroplast RNA editing and chlorophyll biosynthesis.

Reference:

Zhang B, Wu Y, Li S, et al. Chloroplast C-to-U editing, regulated by a PPR protein BoYgl-2, is important for chlorophyll biosynthesis in cabbage. Horticulture Research. 2024;11(3):uhae006.

 

10. Lines 621–658 (Clubroot Resistance): The review should incorporate recent work on the BolC.Pb9.1 locus from wild Brassica macrocarpa, which provides broad-spectrum resistance and associated molecular markers.

Reference:

Zhang X, Han F, Li Z, et al. Map-based cloning and functional analysis of a major quantitative trait locus, BolC.Pb9.1, controlling clubroot resistance in a wild Brassica relative (Brassica macrocarpa). Theoretical and Applied Genetics. 2024;137(2):41.

 

11. References: The reference list contains numerous formatting inconsistencies, including: Inconsistent italicization of Latin names and gene symbols.

Variable capitalization of article titles (e.g., some use title case, others sentence case).

Inconsistent use of full vs. abbreviated author names (e.g., Ref. 28–30).

Missing spaces (e.g., “oilseedBrassica rapa”).

A thorough revision of the reference section is strongly recommended.

 

12. The conclusion could be strengthened by explicitly mentioning future directions, such as the need for more markers for polygenic traits or the integration of genomic selection.

 

 

 

Author Response

Dear Reviewer,

We would like to express our sincere gratitude for your thorough review and the constructive comments on our manuscript.

We have taken all of your suggestions into account and have revised the manuscript accordingly. We believe these revisions have strengthened the paper and we are grateful for your contribution.

The authors would like to extend their special appreciation to the reviewers for their insightful suggestions and for providing relevant literature references.

 

Comments 1: Line 95: The candidate gene for Ms-cd1 is incorrectly given as Bol0357N3. Although the mapping interval reported by Liang et al. is correct, the actual gene was recently identified by Han et al. (2023). Please update the text accordingly.

Response 1: Kindly thank you for the commentary. We give the correct candidate gene for Ms-cd1 (Bol035718).

 

Comments 2: Line 110: The author name “Chen C. et al.” should be simplified to “Chen et al.” for consistency with standard citation style. Please check and revise in the whole manuscript.

Response 2: Thank you for noticing. The manuscript has been revised to ensure the author names conform to the standard citation style.

 

Comments 3: Section 2.1 (DGMS/RGMS): The review should include additional recessive genic male sterility genes beyond ms3, such as BoCYP704B1, for which molecular markers have also been developed.

Response 3: Thank you for commentary. We have included a description of the BoCYP704B1 gene and its linked molecular marker. The scarcity of recessive genic male sterility genes covered in this review reflects both the inadequate characterization of individual candidates and the absence of robust molecular markers for their identification.

 

 

Comments 4: Structural Reorganization: The current grouping of certain traits under inappropriate sections affects the logical flow of the manuscript. Specifically: “Petal color” should not be placed under “Hybrid Breeding”, “Leaf color” and “Cabbage waxiness” are not abiotic stress traits and should be reclassified, possibly under a new section such as “Morphological Traits.”

Response 4: We thank you for highlighting this issue. The review has been restructured to incorporate a new section, "Markers for Morphological Traits," which details molecular markers associated with petal color, leaf color, cabbage waxiness.

 

Comments 5: Section 4.4: The heading “Resistance to downy mildew” is inconsistent with the format of other subheadings (e.g., “Fusarium wilt resistance,” “Black rot resistance”). Please revise for consistency.

Response 5: We kindly appreciate this comment. We have rewritten the title of this section to ensure textual consistency.

 

Comments 6: Line 214: “Xing L. I. et al.” should be “Li et al.” Line 27: “Li Zhi Yuan et al.” should be “Li et al.”

Response 6: Thank you for commentary. As noted in our response to comment #2, we have revised the manuscript to standardize the formatting of author names in accordance with the required citation style.

 

Comments 7: Line 282: The statement that “F₁ hybrids display an intermediate phenotype for this trait” is incorrect. For example, when a white-petaled line is crossed with a yellow-petaled line, the F₁ typically exhibits white petals, not an intermediate color. Please correct this misrepresentation.

Response 7: We deeply appreciate your comments. We have corrected the description of petal colour inheritance.

 

Comments 8: Lines 284–285: The *cpc-1* locus (candidate gene BoCCD4) is involved in carotenoid degradation, not biosynthesis. This should be clarified to avoid misunderstanding.

Response 8: We deeply appreciate your comments. We have rewritten this section and provided the correct classification for the cpc-1 loci.

 

 

Comments 9: Lines 356–367: The section on yellow leaf mutants should include recent findings on BoYgl-2, a PPR protein involved in chloroplast RNA editing and chlorophyll biosynthesis.

Response 9: Thank you for your precious commentary. The section covering yellow leaf mutants has been expanded with detailed information on the BoYgl-2 locus and associated PPR protein.

 

Comments 10: Lines 621–658 (Clubroot Resistance): The review should incorporate recent work on the BolC.Pb9.1 locus from wild Brassica macrocarpa, which provides broad-spectrum resistance and associated molecular markers.

Response 10: We deeply thank you for your comments. We have incorporated the recent findings on the BolC.Pb9.1 locus.

 

Comments 11: References: The reference list contains numerous formatting inconsistencies, including: Inconsistent italicization of Latin names and gene symbols.

Response 11: Thank you for noticing. We have carefully checked the reference list and corrected any errors.

 

Comments 12: The conclusion could be strengthened by explicitly mentioning future directions, such as the need for more markers for polygenic traits or the integration of genomic selection.

Response 12: Thank you for commentary. We have rewritten the Conclusion section and added information on genomic selection (GS), including how its integration into cabbage breeding programs can advance our understanding of the genetic architecture underlying polygenic traits.

 

Thank you on more time. The changes made in response to your comments have undoubtedly enhanced the quality and clarity of our work.

Beat regards

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Authors thoroughly addressed all the reviewer's comments. In my personal point of view, manuscript is ready for publication