Genetic Parameters and Family Selection of Pinus pseudostrobus var. apulcensis Through Growth and Stem Quality in Mixteca Oaxaqueña Region, Mexico

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors' research is fundamental. The results of the work complement the understanding of the growth and stem quality of Pinus pseudostrobus var. apulcensis. The authors conducted experiments and identified the elite families in Mixteca Oaxaqueña region, Mexico.

The authors also described in detail the results of the work, illustrated their judgments, and conducted a competent discussion of the results.

However, to improve the manuscript, I recommend making some revisions:

1. In abstract, the research background is not clearly stated.
2. Line 29, what does GG mean?
3. The keywords should be Pinus pseudostrobus var. apulcensis, genetic variation, genetic correlation, and early selection.
4. In introduction, Pinus pseudostrobus var. apulcensis should be introduced in detail, especially in reforestation and adaptation.
5. The concluding part of the introduction should emphasize the academic significance of this study.
6. Line 81, where is the nursery ground located?
7. Line 83-85, what are the active ingredients of Osmocote Plus 15-9-12, Folim 84 00-40-40, and Aminofit®, respectively.
8. Line 112, “calculation of genetic parameters and selection” should be removed.
9. Line 150-152, “clone” should be removed.
10. In 3.1, the analysis of variance results should be fully presented.
11. Table 4, the column of difference should be removed.
12. In 4.1, the relationship between the results and soil recovery should be explained in detail.
13. In 4.3, the genetic correlation is not significant between different traits. It is necessary to explain the reasons for this phenomenon, such as sampling errors.
14. The conclusion section is too lengthy and lacks refinement. The authors need to add a future perspective on the work. What are the next steps? What is most relevant? How could this research actually benefit foresters?

Comments on the Quality of English Language

The language used in the manuscript is some grammatical errors, not ensuring readability.

Author Response

Answers to Reviewers’ comments
[Our answers are in blue color]
REVIEWER 1
Comments and Suggestions for Authors
The authors' research is fundamental. The results of the work complement the understanding of the growth and stem quality of Pinus pseudostrobus var. apulcensis. The authors conducted experiments and identified the elite families in Mixteca Oaxaqueña region, Mexico.
The authors also described in detail the results of the work, illustrated their judgments, and conducted a competent discussion of the results.
[Dear reviewer, the authors are deeply grateful for the comments, which contributed to substantially improve the manuscript].
However, to improve the manuscript, I recommend making some revisions:
1. In abstract, the research background is not clearly stated.
[Thank you for your comment. We expanded the first part of the introduction to establish the context of the research (lines 17 to 20 of this version)].
2. Line 29, what does GG mean?
[We appreciate the comment, it was an error, this was eliminated due to modifications to the summary].
3. The keywords should be Pinus pseudostrobus var. apulcensis, genetic variation, genetic correlation, and early selection.
[We appreciate the suggestion. We integrated early selection; genetic variation and genetic correlation were already included in keywords. We considered it unnecessary to integrate Pinus pseudostrobus var. apulcensis because it appears as such in the title].
4. In introduction, Pinus pseudostrobus var. apulcensis should be introduced in detail, especially in reforestation and adaptation.
[Thank you very much for the suggestion. At the suggestion of the other reviewers, most of the introduction was modified to give more weight to the timber motivation of the study, and in the third paragraph the aspects you request were included (Lines 52 to 59 of this version)].
5. The concluding part of the introduction should emphasize the academic significance of this study.
[We appreciate the recommendation. The academic importance of the research was added in the last paragraph of the introduction (lines 89 to 95 of this version)].
6. Line 81, where is the nursery ground located?
[Thank you for the question. We have added the geographic location of the nursery where the plant was produced (lines 102 to 105 of this version)].
7. Line 83-85, what are the active ingredients of Osmocote Plus 15-9-12, Folim 84 00-40-40, and Aminofit®, respectively.
[Fertilizers do not contain a single “active ingredient” as in pharmaceuticals. Instead, they are composed of a balanced mixture of essential plant nutrients. The information was supplemented by further specifying the nutrients contained in the fertilizers (lines 107 to 111 of this version)].
8. Line 112, “calculation of genetic parameters and selection” should be removed.
[Thank you. Removed (line 140 of this version)].
9. Line 150-152, “clone” should be removed.
[Thanks for the feedback. Fixed (lines 176-178 of this version)].
10. In 3.1, the analysis of variance results should be fully presented.
[We appreciate the suggestion. We believe that it is not necessary to present the complete analyses of variance in the manuscript; currently, few scientific articles present it; however, following the suggestion, the results of the analysis of variance for all variables are included in the supplementary material (now Table S3) and indicated in the footnote of Table 1 (line 201)]
11. Table 4, the column of difference should be removed.
[Okay, deleted]
12. In 4.1, the relationship between the results and soil recovery should be explained in detail.
[We appreciate the suggestion. We complement the discussion by emphasizing the relationship of the results with soil recovery (lines 298 to 307 of this version)].
13. In 4.3, the genetic correlation is not significant between different traits. It is necessary to explain the reasons for this phenomenon, such as sampling errors.
[Many thanks for the suggestion. We extend the discussion to explain the possible reasons for the lack of significance of the genetic correlations (lines 457 to 470 of this version)].
14. The conclusion section is too lengthy and lacks refinement. The authors need to add a future perspective on the work. What are the next steps? What is most relevant? How could this research actually benefit foresters?
[We welcome comments. We synthesize the conclusions to present the most relevant and include the recommendation for foresters. We considered that “next steps” would not really be part of the conclusions, since they do not correspond to the scope of the research developed. We thought that “next steps” would fit better in the discussion, therefore it was included at the end of this section].
Comments on the Quality of English Language
The language used in the manuscript is some grammatical errors, not ensuring readability.
[Thank you for your comments. We make grammatical and syntax corrections throughout the document to ensure fluency and comprehension. Changes are marked in blue letters].

[[Dear reviewer, all changes (including those suggested by other reviewers) are presented in the document in blue letters for easy identification. We, the authors, reiterate our thanks]]

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present an analysis of genetic parameters and family selection for growth and stem quality of Pinus pseudostrobus var. apulcensis. Overall the analysis is well executed and the Results and Discussion are well thought through. The study makes a valuable contribution to the field. I do have some points of concern as detailed below.

1. The age of four years is pretty early for trait evaluation and selection in progeny test, especially for pines whose final rotation period of plantations is relatively long, say, longer than 15 or 20 years. The authors should mention this and its possible consequence (or potential usage) for genetic evaluation of progeny test in Introduction and/or Discussion.
2. Phenotypic and genetic correlations are usually estimated based on phenotypic and additive genetic co-variances, respectively, instead of the method or equation used by the authors. Corrections may be needed therein.

Comments on the Quality of English Language

There were some grammatical, syntax, or spelling errors. For instance, italic scientific name for species in Abstract and Conclusions (maybe elsewhere), mentioning the abbreviation of GC at the first presence of full description in Abstract, Yij instead of Yjk in line 118, replacing the full stops with comma or semicolon in lines 63-67 as a full stop cannot be used at the end of a phrase, addition of the version of SAS (line 114), replacing the semicolon with ‘, and’ in line 156, addition of unit (%) to the Variance component (not componets) in the first row in Table 1, and usually only the first letter to be capital for the first row of each column in tables. The authors can check throughout the text.

      It would be good to have the paper re-read and minor corrections made by a native English speaker.

Author Response

Answers to Reviewers’ comments
[Our answers are in blue color]

REVIEWER 2
The authors present an analysis of genetic parameters and family selection for growth and stem quality of Pinus pseudostrobus var. apulcensis. Overall the analysis is well executed and the Results and Discussion are well thought through. The study makes a valuable contribution to the field. I do have some points of concern as detailed below.
[The authors are very grateful for the comments and observations; they undoubtedly contribute substantially to improving the manuscript].
1. The age of four years is pretty early for trait evaluation and selection in progeny test, especially for pines whose final rotation period of plantations is relatively long, say, longer than 15 or 20 years. The authors should mention this and its possible consequence (or potential usage) for genetic evaluation of progeny test in Introduction and/or Discussion.
[We agree on the observation. We restructured the introduction, addressed the aspect of early selection and the use of the information generated (Lines 74-78 and 91-95). It was also addressed in the latter part of the discussion (Lines 545-556)].
2. Phenotypic and genetic correlations are usually estimated based on phenotypic and additive genetic co-variances, respectively, instead of the method or equation used by the authors. Corrections may be needed therein.
[The equations we use to obtain the phenotypic and genetic correlations have been widely used. Therefore, we add more recent references to support the use of the equations used (lines 161-162)].
Comments on the Quality of English Language
There were some grammatical, syntax, or spelling errors. For instance, italic scientific name for species in Abstract and Conclusions (maybe elsewhere), mentioning the abbreviation of GC at the first presence of full description in Abstract,
[Thank you for the comment, it was reviewed and corrected throughout the document].
Yij instead of Yjk in line 118,
[Thank you, corrected (line 146 of this version)].
replacing the full stops with comma or semicolon in lines 63-67 as a full stop cannot be used at the end of a phrase,
[We appreciate the comment. We replace periods with semicolons (lines 81 to 86 of this version)].
addition of the version of SAS (line 114),
[Thank you, the version of SAS used has been added (Line 142 of this version)].
replacing the semicolon with ‘, and’ in line 156,
[The comment is appreciated. We replace “;” by “, and” (line 182 of this version)].
addition of unit (%) to the Variance component (not componets) in the first row in Table 1, and usually only the first letter to be capital for the first row of each column in tables. The authors can check throughout the text.
[Thank you very much. The unit (%) was added, and according to Forests table format, the first letters of each word of the column title are capitalized, corrected].
It would be good to have the paper re-read and minor corrections made by a native English speaker.
[Thank you for your suggestion. Syntax and grammar have been checked throughout the document, changes are shown in blue letters].

[[Dear reviewer, all changes (including those suggested by other reviewers) are presented in the document in blue letters for easy identification. We, the authors, reiterate our thanks]]

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript describes a progeny test of 64 families of Pinus pseudostrobus var. apulcensis that assessed growth and stem form qualities and estimated genetic parameters.  The manuscript is generally well written though there a few words are used that seem incorrect, likely due to mis-translation.  The study design is clearly described along with the analysis and results, and the subject is of interest to tree breeders and anyone working either with this species or in this specific geographic region. However, the introduction starts off with statements about the problem of deforestation in Mexico along with soil loss and degradation, but there is no discussion regarding how the expanded use of P. pseudostrobus var. apulcensis would directly address the issue of soil loss.  Yes, reforestation is important, but trees take many years to fully occupy a site after planting and do not provide short term soil stabilization.  There are other plants that are far more effective to use for soil stabilization.  The main intent of most tree breeding programs is for improved wood production and quality, and clearly this study is focused on the traits that would increase wood production and value.  The relationship with soil loss and site degradation is tenuous at best.  If soil stabilization is truly the main goal of reforestation, then improved stem traits is of little value, and improved growth is only of value if improved stem growth also leads to improved root growth, which was not investigated in this study.  I feel like the authors are attempting to package this research in a restoration context when it seems like economic value is the dominant factor driving this research.  Why not be completely transparent in the motivation for this research? I think the authors have done themselves a disservice in trying to package this research as something it is not. In addition,  I found the discussion section to be somewhat lacking.  Most of the discussion section simply provides comparisons with other published results, which is useful for reference and context, but there is very little discussion regarding how the results of this study fit into the larger context or their direct implications for operational use.  I feel that this should be expanded. Overall I think this research warrants publication but revisions are needed to the manuscript before it is acceptable.

Specific comments and edits are listed below.

Lines 41-43:  There are better plants than trees for reducing soil loss, specifically grasses and forbs that can occupy a site faster than trees.

Lines 44-53:  This information seems like it would be more appropriate to include in the discussion section rather than here in the introduction.  When I first read this I was wondering why Pinus greggii was being discussed rather than Pinus pseudostrobus.

Line 55: Pseudostrobus is misspelled

Lines 59-60:  the word necessary is used twice in this sentence making for awkward reading

Line 80:  beneficiation is not correct.  I think the authors mean seed “collection”

Line 162:  56.65 cm appears to be an error when looking at Table 1.

Lines 223-232:  Is this information necessary?

Lines 350-357:  additional discussion is necessary here.

Line 437:  “legally” is probably not the most appropriate word to use here.

Lines 440-442:  These families are being selected based only on seedling traits though.  It would be useful to add discussion or at least acknowledgement regarding the relationship between juvenile and mature traits.

Lines 444-445:  it is not just “possible” that genetic diversity is low…selecting only 4 families IS low genetic diversity.

Lines 449-450: Even expanding selection to 8 or 16 families is still very low genetic diversity, especially for large scale reforestation across a landscape.  More families are needed, which also means that more than 64 families should be tested if there is a desire to have a higher level of selection intensity.  There is ample discussion in the genetics literature regarding minimum numbers of families to include in order to maintain a broad genetic base.  This information should be included in this manuscript.

Line 480: Scientific name should be in italics

Line 497:  16 should be the absolute MINIMUM used.  For ample genetic diversity even more families would be better.

Author Response

Answers to Reviewers’ comments
[Our answers are in blue color]
REVIEWER 3
Comments and Suggestions for Authors
[The authors are very grateful for the comments, which undoubtedly contributed to substantially improve the manuscript].

This manuscript describes a progeny test of 64 families of Pinus pseudostrobus var. apulcensis that assessed growth and stem form qualities and estimated genetic parameters. The manuscript is generally well written though there a few words are used that seem incorrect, likely due to mis-translation. The study design is clearly described along with the analysis and results, and the subject is of interest to tree breeders and anyone working either with this species or in this specific geographic region. However, the introduction starts off with statements about the problem of deforestation in Mexico along with soil loss and degradation, but there is no discussion regarding how the expanded use of P. pseudostrobus var. apulcensis would directly address the issue of soil loss. Yes, reforestation is important, but trees take many years to fully occupy a site after planting and do not provide short term soil stabilization. There are other plants that are far more effective to use for soil stabilization. The main intent of most tree breeding programs is for improved wood production and quality, and clearly this study is focused on the traits that would increase wood production and value. The relationship with soil loss and site degradation is tenuous at best. If soil stabilization is truly the main goal of reforestation, then improved stem traits is of little value, and improved growth is only of value if improved stem growth also leads to improved root growth, which was not investigated in this study. I feel like the authors are attempting to package this research in a restoration context when it seems like economic value is the dominant factor driving this research. Why not be completely transparent in the motivation for this research? I think the authors have done themselves a disservice in trying to package this research as something it is not. In addition, I found the discussion section to be somewhat lacking. Most of the discussion section simply provides comparisons with other published results, which is useful for reference and context, but there is very little discussion regarding how the results of this study fit into the larger context or their direct implications for operational use. I feel that this should be expanded. Overall I think this research warrants publication but revisions are needed to the manuscript before it is acceptable.
[We agree with the point of view that the study of stem growth and quality is more economically motivated than for reforestation. In fact, in spite of soil degradation in this region, successful reforestations have been carried out since the last decade of the last century; therefore, owners now have an urgent need to select phenotypes to obtain higher growth and quality timber. Therefore, we modified almost all the introduction (lines 37-78 of this version) considering their valuable opinions].
Specific comments and edits are listed below.
Lines 41-43: There are better plants than trees for reducing soil loss, specifically grasses and forbs that can occupy a site faster than trees.
[We fully agree, we replace the introduction, highlighting the economic motivation of the study].
Lines 44-53: This information seems like it would be more appropriate to include in the discussion section rather than here in the introduction. When I first read this I was wondering why Pinus greggii was being discussed rather than Pinus pseudostrobus.
[We agree, this information was removed in the introduction, part of it was taken up again in the discussion].
Line 55: Pseudostrobus is misspelled
[Thank you, corrected and checked for correct spelling throughout the manuscript].
Lines 59-60: the word necessary is used twice in this sentence making for awkward reading
[Thank you, this was corrected by replacing the paragraph].
Line 80: beneficiation is not correct. I think the authors mean seed “collection”
[Thank you, in effect, refers to the collection; the correction was made (line 101 of this version)].
Line 162: 56.65 cm appears to be an error when looking at Table 1.
[Thanks for the comment, the correct value is 5.67, it was modified (line 188 of this version)].
Lines 223-232: Is this information necessary?
[Considering their opinion we removed the information and added it at the end of table S3 and it is clarified in lines 249 to 251 of this version of the manuscript].
Lines 350-357: additional discussion is necessary here.
[Your suggestion is appreciated. The discussion was expanded (lines 378 to 393 of this version)].
Line 437: “legally” is probably not the most appropriate word to use here.
[In fact the word “legally” is not necessary in the wording. Removed and reworded at the suggestion of other reviewers].
Lines 440-442: These families are being selected based only on seedling traits though. It would be useful to add discussion or at least acknowledgement regarding the relationship between juvenile and mature traits.
[Thank you for the comment and we offer a big apology. Height and diameter increments were obtained based on initial data (2018) and final data (2022); crown diameter and all stem quality variables were measured in 2022. Therefore, all traits studied correspond to four-year-old plants. The confusion occurred because in methods there was an error (line 105 of the previous version), instead of “In addition, in 2018,...” it should be “In addition, in 2022,...”. In addition to correcting in methods (line 132 of this version), we integrated the relationship of juvenile and mature traits in the discussion (lines 549 to 552 of this version)].

Lines 444-445: it is not just “possible” that genetic diversity is low…selecting only 4 families IS low genetic diversity.
[The comment is appreciated. The wording was modified by stating that the use of four families will reduce genetic diversity (lines 494 to 495 of this version)].
Lines 449-450: Even expanding selection to 8 or 16 families is still very low genetic diversity, especially for large scale reforestation across a landscape. More families are needed, which also means that more than 64 families should be tested if there is a desire to have a higher level of selection intensity. There is ample discussion in the genetics literature regarding minimum numbers of families to include in order to maintain a broad genetic base. This information should be included in this manuscript.
[We appreciate the suggestion. We complement the discussion (lines 498 to 519 of this version)].
Line 480: Scientific name should be in italics
[Thanks for the comment, corrected].
Line 497: 16 should be the absolute MINIMUM used. For ample genetic diversity even more families would be better.
[According to the comment, the wording was modified to emphasize the use of 16 families for timber plantations and it is suggested to use more families for reforestation plantations (lines 500 to 504 of this version).

[[Dear reviewer, all changes (including those suggested by other reviewers) are presented in the document in blue letters for easy identification. We, the authors, reiterate our thanks]]

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

This revised version of the manuscript is greatly improved.  The authors have thoroughly implemented the suggested revisions and carefully responded to the review.  This has significantly improved both the readability of the manuscript and the presentation of the results and their discussion.  I think this paper will be of great interest to tree breeders in general and to the landowners in this region seeking to improve timber output from their lands.