Genetic Variability of Oil Palm in Mexico: An Assessment Based on Microsatellite Markers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

The submitted paper is related to the genetic characterization of 151 oil palm accessions located in Mexico by SSR and RAM markers. To be suitable for the publication there are some issues that need your revision.

Table 2: the explanation of “Y” is missing

Geographical location: should be added a map of the 19 different sites

Table 4: the format and the presentation of the table should be improved. About the allelic size, is very strange to find an SSR marker able to produce an allele of 12.000 bp. (mEgCIR0476). Also, the number of polymorphic alleles detected with polyacrylamide gel is very high (94 bands for two markers). Please it is necessary to add as a supplementary file the pictures of these two cases. How many missing data did you have for each markers? Did you set up a limit of them?

Figure 1: I prefer to have a figure of the completed dendrogram, not aggregated, with the 151 samples. (Prepare a supplementary table with the complete list of the samples and use a code made by progressive number and letter to identify the site.

Table 5: you can delete it

Figure 3: it is not clear, try to use another type of representation

It is necessary to carefully revise the text and the English.

 

Comments on the Quality of English Language

It is necessary to carefully revise the text and the English.

Author Response

Response to Reviewers

Reviewer 1:

1. Table 2: the explanation of “Y” is missing

R/ The explanation of Y was included in Table 2 (line 143).

2. Geographical location: should be added a map of the 19 different sites.

R/ A map with the geographical location of 19 sites where samples were collected was included as Figure 1.

3. Table 4: the format and the presentation of the table should be improved. About the allelic size, is very strange to find an SSR marker able to produce an allele of 12.000 bp. (mEgCIR0476).

R/ After carefully reviewing the gels, no allele was found to have that band size of 12000 bp, this was corrected in table 4, as well as in matrices and dendrogram.

Also, the number of polymorphic alleles detected with polyacrylamide gel is very high (94 bands for two markers). Please it is necessary to add as a supplementary file the pictures of these two cases. R/ We re-examined all gels obtained in this study, in the case of the two markers pointed out, effectively there were errors in the counting of the amplified products, for this reason we to re-count the amplified bands, the new data were used to correct the matrices, and analyses were re-run to rectify the data presented in Table 4 and the dendrogram. Figures with polyacrylamide gels of two cases were included as supplementary (FS1 and FS2).

How many missing data did you have for each marker? Did you set up a limit of them?

R/ There was not missing data in this study, all molecular data was recorded as presence (1) or absence (0) as there was explained in Material and Methods section, 2.4 Data analysis.

4. Figure 1: I prefer to have a figure of the completed dendrogram, not aggregated, with the 151 samples. (Prepare a supplementary table with the complete list of the samples and use a code made by progressive number and letter to identify the site).

R/ This Figure, now is Figure 2 and was replaced with the completed dendrogram. A supplementary table (TS1) with the complete list of samples was include.

5. Table 5: you can delete it

R/ Table 5 was eliminated

6. Figure 3: it is not clear, try to use another type of representation

R/ Figure 3 is the graphical representation in two and three dimensions given by the program (NTSYSpc software, version 2.02e) used to carry out these analyses.

7. It is necessary to carefully revise the text and the English

R/ This manuscript was reviewed by a retired colleague Dr. Andrew James, who is British.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper gives new and exciting findings that can be useful for future Oil Palm breeding programs in Mexico. The presented methodological approach can also be applied to other species to determine the genetic patterns.

The title is appropriate and informative. The original topic and the obtained results will fill the gap concerning the use of Oil Palm genetic resources and show the possibilities of using molecular markers for the population’s genetic structure determination.

The introduction summarizes current knowledge and identifies gaps; the reason for conducting this research is clearly formulated.

The methods are appropriate and clearly described. I suggest transferring Table 3 with the associated text from the Results section to the Material and Method because it describes the starting material used for the research.

The results are comprehensively reported and mostly supported by figures and tables which are helpful for the understanding of the findings.

 

The conclusions drawn transfer the presented arguments; however, some concrete conclusions regarding which origin should be used in future breeding programs are lacking. This would help the practice receive some concrete proposals for further work.

Author Response

Reviewer 2:

1. The methods are appropriate and clearly described. I suggest transferring Table 3 with the associated text from the Results section to the Material and Method because it describes the starting material used for the research.

R/ The authors suggest that Table 3 remain in the results, because although it is true that the locations for sampling had previously been selected, the number of samples taken was a decision at each sampling site, since it depended on the size of the sample. existing populations and this information was not previously available.

 

2. The conclusions drawn transfer the presented arguments; however, some concrete conclusions regarding which origin should be used in future breeding programs are lacking. This would help the practice receive some concrete proposals for further work

R/   In our study we found great diversity in the oil palm germplasm of the different plantations sampled, in the producing states, but the authors consider that we cannot suggest one or several specific accessions for breeders to start their work, since to select the parents that will be used in a breeding program, in addition to the molecular information that we obtained on their variability, data on the behavior of each accession, in terms of yield, fruit characteristics, resistance to biotic and abiotic stresses, are required. And we do not have these data, so we limit ourselves to indicating which are the most and least similar genotypes, the use that the breeders give to the information that we provide will depend on the objective of the improvement. However, our findings are useful for them, since the degree of existing genetic variability was not known, nor was it known what the genetic relationship was between all the accessions evaluated. Also a sentence about the use that can be given to the genetic fingerprints obtained in some marker-assisted breeding strategy was added in conclusions, lines 383-385.