Homoeologous Chromosome Pairing and Alien Introgression in Backcrossing Progenies Derived from Hybrids Solanum tuberosum (+) Mexican 2x (1 EBN) B-Genome Potato Species

Round 1

Reviewer 1 Report

The equal signs are missing spacing, relative to the chromosome number: 2n = 2x = 48. The n and x should be italicized. Correct all text.

Author Response

We are very grateful to the Reviewer 1 for the remarks made. Appropriate changes have been made to the text of the manuscript.

Best regards,

Tatjana Gavrilenko and co-authors

Reviewer 2 Report

1 - The only important suggestion is to put the arrows in full white or blue colors, not only the line. 

2 - In Figure 4 g and e, we can see in several DAPI-colored chromosomes some red/pink hybridization spots. Does it have any probe or old information since the slides were re-probing? Try to make this clear in the legend of Figure 4 the information.

3 - Standardize all references, for instance, the ref. n.1 have the article's year of publication not bold. And we have more of the same mistake, see again the formatting as a double-check.

Author Response

We are very grateful to the Reviewer 2 for the remarks made. Appropriate changes have been made to the text of the manuscript.

-Comment of Reviewer – “In Figure 4 g and e, we can see in several DAPI-colored chromosomes some red/pink hybridization spots. Does it have any probe or old information since the slides were re-probing? Try to make this clear in the legend of Figure 4 the information.”

-Our Response – “The red hybridization spots in several DAPI-colored chromosomes (Figures 4e, 4g) are the remains of the GISH signals”. The corresponding comment was included in the legend of Figure 4".

-Comment of Reviewer – “ Standardize all references, for instance, the ref. n.1 have the article's year of publication not bold. And we have more of the same mistake, see again the formatting as a double-check”.

-Our Response – “We checked all references and made changes@.

-Suggestion of Reviewer –“ to put the arrows in full white or blue colors, not only the line”. 

-Our Response – “We have highlighted only the contours (the lines) of the arrows in order to focus on the chromosomes and chromosomal associations in the figures, and not on the auxiliary tools (the arrows). This decision is explained by the relatively small size of potato chromosomes (ranging in length from 1.0 to 3,5 µm ), which in the photos are comparable to the size of the arrows”.

Best regards,

Tatjana Gavrilenko and co-authors

Reviewer 3 Report

This manuscript detected genomic chromosome compositions of hybrids between S. tuberosum and its wild species, and derivatives of BC progenies by GISH and FISH. Further, homoeologous chromosome pairing and detected resistance genes introgression in the backcrossing derivatives between S. tuberosum and three diploid B-genome potato species were also uncovered. The results are helpful for the breeding of potato varieties with disease and pest resistance. Here are a few questions:

1. Lines 142-143. The relationship between “two selected genotypes of somatic hybrids” and “three inter-specific combinations” is not clear in the section 2.1. Plant Materials. Fig. 1 does not describe this either. It is proposed that the contents of lines 246-251 be transferred to the 2.1 section.

2. Line 152. Should “accession GLKS 31607” be written as “accession GLKS 1607”?

3. Lines 184-187: The flower buds and root tips fixed in Carnoy's solution and then stored at -20⁰C. The description of the experimental procedure is inconsistent with the description of Rakosy-Tican et al. [16] in the manuscript, where they stored the root tips in 70% alcohol at 4 °C. The manuscript describes the use of Carnoy's solution at -20⁰C directly for storage. Is direct storage with Carnoy's solution described in the manuscript an improvement on the experimental procedure? Or was chromosome preparation performed immediately after short-term storage?

4. Lines 287-288. The phrase “all three signals were located on a chromosomes of the A-genome of S. tuberosum, indicating missing of one of four satellite chromosome of potato” is ambiguous. Should "a chromosomes" be" three chromosomes"?

5. Some descriptions are repeated and verbose. They should be concise. For example, the content in line 279-281 seemly repeatedly described in line 282-285.

6. In line 410-411. “None of the chromosomes of the B-genome did not form homologous B-B bivalents in four analyzed BC1 hybrids” means “None of the chromosomes of the B-genome did form homologous B-B bivalents in four analyzed BC1 hybrids”?

A few descriptions should be checked. Concised descrption would be better.

Author Response

We are very grateful to the Reviewer 3 for the remarks made. Appropriate changes have been made to the text of the manuscript.

-Comment 1 of Reviewer – “ Lines 142-143. The relationship between “two selected genotypes of somatic hybrids” and “three inter-specific combinations” is not clear in the section 2.1. Plant Materials. Fig. 1 does not describe this either. It is proposed that the contents of lines 246-251 be transferred to the 2.1 section.”

-Our Response – “The contents of lines 246-251 was transferred to the 2.1 section “Plant Material”.

-Comment 2 of Reviewer – “Line 152. Should “accession GLKS 31607” be written as “accession GLKS 1607 ?”.

-Our Response – “this is misprint. Accession GLKS 1607 should be accession GLKS 31607. We checked the Manuscript and Supplements and corrected the number of parental accession of S. pinnatisectum.

-Comment 3 of Reviewer – “Lines 184-187: The flower buds and root tips fixed in Carnoy's solution and then stored at -20⁰C. The description of the experimental procedure is inconsistent with the description of Rakosy-Tican et al. [16] in the manuscript, where they stored the root tips in 70% alcohol at 4 °C. The manuscript describes the use of Carnoy's solution at -20⁰C directly for storage. Is direct storage with Carnoy's solution described in the manuscript an improvement on the experimental procedure? Or was chromosome preparation performed immediately after short-term storage?”

-Our Response – “Root tips and flower buds were fixed in Carnoy's solution; they were immersed in fresh prepared Carnoy's solution and placed in a freezer at -20⁰C. Usually, fixed plant material that was placed in freezer was used in the work during a month. In our experience, this approach usually yields better cytological preparations than using plant material after the storage in 70% ethanol”.

-Comment 4 of Reviewer – “Lines 287-288. The phrase “all three signals were located on a chromosomes of the A-genome of S. tuberosum, indicating missing of one of four satellite chromosome of potato” is ambiguous. Should "a chromosomes" be" three chromosomes"?

-Our Response – “We made the appropriate changes. Indeed, there should be "three chromosomes".

-Comment 5 of Reviewer – “Some descriptions are repeated and verbose. They should be concise. For example, the content in line 279-281 seemly repeatedly described in line 282-285”.

-Our Response – “We checked the text and made the appropriate changes in lines 282-285 and in a number of other sentences”. -Comment 6 of Reviewer – “In line 410-411. “None of the chromosomes of the B-genome did not form homologous B-B bivalents in four analyzed BC1 hybrids” means “None of the chromosomes of the B-genome did form homologous B-B bivalents in four analyzed BC1 hybrids?”.-Our Response – “thanks for this note, we have made this correction».

Best regards,

Tatjana Gavrilenko and co-authors