Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.]

Daniel Nyadanu; Samuel Tetteh Lowor; Abraham Akpertey; Dèdéou Apocalypse Tchokponhoué; Prince Pobee; Jerome Agbesi Dogbatse; Daniel Okyere; Frederick Amon-Armah; Micheal Brako-Marfo

doi:10.1371/journal.pone.0242972

Peer Review History

Original SubmissionJuly 3, 2020
17 Jul 2020 Decision Letter - Prasanta K. Subudhi, Editor PONE-D-20-17736 Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.] PLOS ONE Dear Dr. Nyadanu, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we have decided that your manuscript does not meet our criteria for publication and must therefore be rejected. Specifically, the manuscript is about phenotypic variation for nutritional and phenolic traits in 25 genotypes of Cola nitida, a minor crop in Africa. Due to its cultivation in in very few countries in the world, it will be of limited interest for PLoS ONE readers. The literature presented in the manuscript omitted several studies in this crop. This study is too preliminary and does not advance science to the next level. I am sorry that we cannot be more positive on this occasion, but hope that you appreciate the reasons for this decision. Yours sincerely, Prasanta K. Subudhi, Ph.D. Academic Editor PLOS ONE [Note: HTML markup is below. Please do not edit.] [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] - - - - - For journal use only: PONEDEC3 https://doi.org/10.1371/journal.pone.0242972.r001
Revision 1
19 Aug 2020 Author Response Response to Comment 1. We are particularly shocked about the idea that a paper is rejected because someone thought that the crop the manuscript targeted is a minor crop inAfrica. Sorry, but Minor crops in Africa also or should also matter in Science. In fact, PLoS ONE clearly indicates that: “it evaluates submitted manuscripts on the basis of methodological rigor and high ethical standards, regardless of perceived novelty”. Prof Preasanda K. Subuthi did not point out any methodological pitfall in this manuscript. We strongly believe that this decision needs to be reviewed since we are confident about the methodological rigour we used in the manuscript. We would be glad if the manuscript could be reassessed by another editor who truly knows the decision’s rules of the respected PLoS One Journal. Editor’s comment 2. The literature presented in the manuscript omitted several studies in this crop Response to Comment 2. We would like to recall that this manuscript is not a review, so we only used literatures relevant to the specific aspects tackled in the manuscript. In addition, the editor comment seemed vague and did not point out specifically what he would like to see in the manuscript’s background. We would be happier if he indicated what he thought we did not take into account. We are confident that we used the last literature on the species Genetics and breeding. Editor’s comment 3. This study is too preliminary and does not advance science to the next level. Response to Comment 3. Our study is the first in its kind to screen variability of bioactive compounds in Cola nitida. It offers first-order decision making information Attachments Attachment Submitted filename: Response to reviewers.docx https://doi.org/10.1371/journal.pone.0242972.r002
16 Sep 2020 Decision Letter - Arun Jyoti Nath, Editor PONE-D-20-17736R1 Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.] PLOS ONE Dear Dr. Nyadanu, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. ============================== ACADEMIC EDITOR: Authors are requested to make a major revision before resubmitting the manuscript for consideration. ============================== Please submit your revised manuscript by Oct 31 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols We look forward to receiving your revised manuscript. Kind regards, Arun Jyoti Nath Rosalyn B. Angeles-Shim, PhD Academic Editors PLOS ONE Journal Requirements: 1.Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. We suggest you thoroughly copyedit your manuscript for language usage, spelling, and grammar. If you do not know anyone who can help you do this, you may wish to consider employing a professional scientific editing service. Whilst you may use any professional scientific editing service of your choice, PLOS has partnered with both American Journal Experts (AJE) and Editage to provide discounted services to PLOS authors. Both organizations have experience helping authors meet PLOS guidelines and can provide language editing, translation, manuscript formatting, and figure formatting to ensure your manuscript meets our submission guidelines. To take advantage of our partnership with AJE, visit the AJE website (http://learn.aje.com/plos/) for a 15% discount off AJE services. To take advantage of our partnership with Editage, visit the Editage website (www.editage.com) and enter referral code PLOSEDIT for a 15% discount off Editage services. If the PLOS editorial team finds any language issues in text that either AJE or Editage has edited, the service provider will re-edit the text for free. Upon resubmission, please provide the following: ● The name of the colleague or the details of the professional service that edited your manuscript ● A copy of your manuscript showing your changes by either highlighting them or using track changes (uploaded as a supporting information file) ● A clean copy of the edited manuscript (uploaded as the new manuscript file) 3. To comply with PLOS ONE submissions requirements for field studies, please provide the following information in the Methods section of the manuscript and in the “Ethics Statement” field of the submission form (via “Edit Submission”): a) Provide the name of the authority who issued the permission for each location (for example, the authority responsible for a national park or other protected area of land or sea, the relevant regulatory body concerned with protection of wildlife, etc.). If the study was carried out on private land, please confirm that the owner of the land gave permission to conduct the study on this site. b) For any locations/activities for which specific permission was not required, please - i. state clearly that no specific permissions were required for these locations/activities, and provide details on why this is the case - ii. confirm that the field studies did not involve endangered or protected species For more information about PLOS ONE submissions requirements for field studies, please refer to http://journals.plos.org/plosone/s/submission-guidelines#loc-animal-research. Additional Editor Comments (if provided): This manuscript entitled ‘Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl] by Nyadanu et al. reports the evaluation of 25 kola genotypes for nutritional traits and phenolic contents. Heritability estimates showed higher genetic control of the phenolic contents in kola nuts but not the nutritional characteristics. Genotypes that can be used as donors in breeding for both nutritional and phenolic traits were identified. While the study provides a baseline for evaluating kola genotypes for breeding purposes and will be of interest to a range of scientists and breeders working on orphan crops, the manuscript needs to be extensively corrected for content (specifically materials and methodology), grammar, spelling, syntax and formatting before it can be considered for publication in PLoSONE. 1. Information on the experimental materials used in the study needs to be clarified. In page 5, line 92, the authors mentioned using 25 ‘clones’ of C. nitida. Clones are individuals having similar genetic constitution. For a study aimed at looking at genetic variability in any trait, the use of clones does not make any sense since each of these individuals will have the same genotype, ergo the same phenotype. Even if variation for a specific trait is observed, the variation would not be significant. But looking at Table 1, significant variation in pod yield, and nut weight and color among the ‘clones’ have been reported. While yield and weight are quantitative traits that are affected by the environment, the data presented in Table 1 does not conform with the expected intra-clonal variation. To make matters more complicated, in page 8, line 116, the authors mentioned ‘grafting’ in relation to the 25 ‘genotypes’ used in the study. It is unclear if the materials used in the study were scions from a single plant (clones) grafted to 25 different rootstock genotypes or 25 different scions grafted to the same rootstock genotype? This is important especially because one of the objectives of the study is identifying genotypes that can be used in breeding. IF the materials used in the study are indeed grafts, the interaction between scion and grafts might have some effect in the traits examined and this should be determined prior to recommending genotypes that can be used as donors in breeding. 2. Page 4 line 67-73. The first and last sentence of this paragraph are contradictory. 3. Details about the methodology used for nitrogen, protein, carbohydrate and phenolic analysis should be provided. The readers should not have to go back to the cited papers for the full methodology used in the chemical analysis. 4. The manuscript needs to be checked for several grammatical, typographical and spelling errors, formatting, as well as syntax to improve the overall readability of the paper. Examples: a. Page 3, line 45: Cola acuminata should be changed to C. acuminate b. Page 3, lines 49-50: This sentence is missing a period. c. Page 3, line 51: “The kola industry offers’ not ‘offer’. d. Page 3, line 59-60: Sentence can be paraphrased as ‘Bioactive compounds (phytonutrients) such as carotenoids and phenolic acids are health-promoting compounds that act against cardiovascular diseases and various types of cancer.’ e. Page 4, line 74: ‘bioactive compounds’ should be changed to ‘bioactive compound’ f. Page 4, line 74: wrong spelling of ‘content’ and ‘greatly’ g. Page 4, line 74: ‘…contents of fruits are’ not ‘…is’ h. Page 4, line 80-82: Sentence needs to be corrected. Wrong usage of grammar and sentence construction. i. Page 5, line 99: Use the symbol for ‘degrees’ instead of superscripting the number ‘zero’. j. Page 5, line 102: Remove comma after April. k. Page 8, line 116: The phrase ‘The grafted materials the 25 kola genotypes..’ is unclear. Please paraphrase. l. Page 11, line 169: Subheading title is unclear. Please paraphrase. m. Page 11, line 171: wrong spelling of ‘between’ n. Page 11, lines 174, 176 and 177: What does the ‘()’ after the stat test mean? o. Page 16, lines 259-261: the five variable mentioned need not be in bold. Also, flavonoids and phenols should not be capitalized. p. Page 16, line 264: change ‘...flavonoids and phenols contents’ to ‘…flavonoid and phenol contents’. q. Page 17 line 271: Remove ‘an’ in ‘Breeding fruits with an enhanced nutritional..’ r. Page 17, line 274: Change has to have s. Page 17, line 283: Put a space between ‘..nutraceutical contents’ and the citation [48] t. Page 21, line 322: No space after the sentence and the period. u. Page 21, line 323: Add a space between ‘in’ and ‘a’. v. The manner by which P values were written were not consistent across the manuscript. w. Tables should be re-formatted according to PLoSONE specifications. x. The references should be checked for formatting and typographical and spelling errors. Note: The examples provided does not represent all the grammatical, typographical, spelling and formatting errors in the manuscript. The authors should have a responsibility in making sure that these issues are addressed before re-submitting. Thank you. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0242972.r003
Revision 2
25 Oct 2020 Author Response Response to the reviewers While the study provides a baseline for evaluating kola genotypes for breeding purposes and will be of interest to a range of scientists and breeders working on orphan crops, the manuscript needs to be extensively corrected for content (specifically materials and methods), grammar, spelling, syntax and formatting before it can be considered for publication in PloSONE. Response: We wish to thank the editor for his positive comments and suggestions to fine tune the manuscript. The corrections suggested were accepted in good faith. Corrections have been carried out on the materials and methods, grammar, spelling, syntax and formatting as suggested. These corrections could be seen in the manuscript with the track changes. Thank you. 1. Information on the experimental materials used in the study needs to be clarified. In page 5, line 92, the authors mentioned using 25 clones of C. nitida. Clones are individuals having similar genetic constitution. For a study aimed at looking at genetic variability in any trait, the use of clones does not make any sense since each of these individuals will have the same genotype, ergo the same phenotype. Even if variation for a specific trait is observed, the variation would not be significant. But looking at Table 1, significant variation in pod yield and nut weight and color among the clones have been reported. While yield and weight are quantitative traits that are affected by the environment, the data presented in Table 1 does not conform to the expected intra-clonal variation. To make matters more complicated, in page 8, line 116, the authors mentioned ‘grafting’ in relation to the 25 genotypes used in the study. It is unclear if the materials used in the study were scions from a single plant (clones) grafted to 25 different rootstock genotypes or 25 different scions grafted to the same rootstock genotype? This is important especially because one of the objectives of the study is identifying genotypes that can be used in breeding. If the materials used in the study are indeed grafts, the interaction between scion and grafts might have some effect in the traits examined and this should be determined prior to recommending genotypes that can be used as donors in breeding. Response The 25 clones means 25 genotypes of kola. We refer to them as clones because they were vegetatively propagated through grafting and planted as a research trial. The 25 genotypes do not have the same genetic constitution and their phenotypes are not the same. The cuttings of the 25 genotypes were grafted on a rootstock of one genotype or of same genetic background. Therefore, there was no rootstock and scion interaction. To make it clear to our readers, the term “clones” has been changed to “genotypes” and the paragraphs rephrased to make issues clear to our readers. The changes can be seen clearly in the manuscript with track changes. Thank you. 2. Page 4 line 67-73. The first and last sentence of this paragraph are contradictory. Response: Comment has been considered in revising the manuscript. The sentence has been rephrased to take out the contradiction. 3. Details about the methodology used for nitrogen, protein, carbohydrate and phenolic analysis should be provided. The readers should not have to go back to the cited papers for the full method. Response: Details of the methodology for nitrogen, protein, carbohydrate and phenolic analysis has been provided in revising the manuscript. Thank you. 4. The manuscript needs to be checked for several grammatical, typographical and spelling errors, formatting, as well as syntax to improve the overall readability of the paper. Response: This comment has been considered in revising the manuscript. The corrections on grammar, typographical and spelling errors, formatting and syntax was carried out throughout the manuscript. Examples: a. Page 3, line 45: Cola acuminate should be changed to C. acuminate Response: The correct one is Cola acuminata. b. Page 3, lines 49-50: This sentence is missing a period. Response: c. Page 3, line 51: “The kola industry offers” not “offer” Response: Thank you for the correction. The correction has been implemented. d. Page 3, line 59-60: Sentence can be paraphrased as “Bioactive compounds (phytonutrients) such as carotenoids and phenolic acids are health-promoting compounds that act against cardiovascular diseases and various types of cancer.” Response: Thank you for the correction. The correction has been implemented. e. Page 4, line 74: ‘bioactive compounds’ should be changed to ‘bioactive compound’ Response: Thank you for the correction. The correction has been implemented. f. Page 4, line 74: wrong spelling of ‘content’ and ‘greatly’ Response: Thank you so much for identifying the spelling mistakes. Corrections has been implemented. They were rightly spelled. g. Page 4, line 74: ‘ …contents of fruits are’ not ‘….is’ Response: Thank you for the correction. Correction has been implemented. h. Page 4, line 80-82: Sentence needs to be corrected. Wrong usage of grammar and sentence correction. Response: Thank you for pointing this out. The sentence has been rephrased and grammar corrected. This can be clearly seen in the manuscript with track changes. i.Page 5, line 99: Use the symbol for ‘degrees’ instead of superscripting the number ‘zero’ Response: Thank you for the correction. The correction has been implemented. The symbol of “degrees” was used. j. Page 5, line 102: Remove comma after April. Response: Thank you for the correction. The correction has been carried out. k. Page 8, line 116: The phrase “the grafted materials the 25 kola genotypes….’ Is unclear. Please paraphrase. Response: Thank you for the correction. Those phrases has been paraphrased to make them clearer. l. Page 11, line 169: Subheading title is unclear. Please paraphrase. Response: Thank you for the correction. The subheading has been paraphrased to make it clear. The corrections can be clearly seen in the manuscript with track changes. m. Page 11, line 171: wrong spelling of ‘between’ Response: Thank you for the correction. The Correction has been implemented. n. Page 11, lines 174, 176 and 177: What does the ‘()’ after the stat test mean? Response: It is a script language which translates the way functions are written in R. o. Page 16, lines 259-261: the five variable mentioned need not be in bold. Also, flavonoids and phenols should not be capitalized. Response: Thank you for the correction. The corrections were considered in revising the manuscript. p. Page 16, line 264: change ‘………flavonoids and phenols contents’ to ‘…..flavonoid and phenol contents’. Response: Thank you for the correction. The correction has been carried out. q. Page 17 line 271: Remove ‘an’ in ‘Breeding fruits with an enhanced nutritional…’ Response: The correction was considered in revising the manuscript. Thank you. r. Page 17, line 274: change has to have Response: The correction was considered in revising the manuscript. Thank you. s. Page 17, line 283: Put a space between ‘…nutraceutical contents’ and the citation [48] Response: The correction was considered in revising the manuscript. Thank you. t. Page 21, line 322: No space after the sentence and the period. Response: The correction was considered in revising the manuscript. Thank you. u. Page 21, line 323: Add a space between ‘in’ and ‘a’. Response: The correction was considered in revising the manuscript. Thank you. v. The manner by which P values were written were not consistent across the manuscript. Response: The correction was considered in revising the manuscript. The manner in which P values are written is now uniform across the manuscript. Thank you. w. Tables should be re-formatted according to PLoSONE specifications. Response: Comment was considered in revising the manuscript. Tables has been formatted according to PLoSONE specifications. x. The references should be checked for formatting and typographical and spelling errors. Response: Comment was considered in revising the manuscript. All references were listed and well formatted. Typographical and spelling errors has been corrected. The whole manuscript was revised and corrections were carried out. Corrections can be seen in the manuscript with track changes. Attachments Attachment Submitted filename: Response to the reviewers.docx https://doi.org/10.1371/journal.pone.0242972.r004
4 Nov 2020 Decision Letter - Arun Jyoti Nath, Editor PONE-D-20-17736R2 Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.] PLOS ONE Dear Dr. Nyadanu, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. ============================== ACADEMIC EDITOR: Thank you for submitting the revised manuscript. Please provide a high resolution image for the Figure 2 and 3. ============================== Please submit your revised manuscript by Dec 19 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols We look forward to receiving your revised manuscript. Kind regards, Arun Jyoti Nath Academic Editor PLOS ONE [Note: HTML markup is below. Please do not edit.] [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0242972.r005
Revision 3
7 Nov 2020 Author Response Response to the reviewers While the study provides a baseline for evaluating kola genotypes for breeding purposes and will be of interest to a range of scientists and breeders working on orphan crops, the manuscript needs to be extensively corrected for content (specifically materials and methods), grammar, spelling, syntax and formatting before it can be considered for publication in PloSONE. Response: We wish to thank the editor for his positive comments and suggestions to fine tune the manuscript. The corrections suggested were accepted in good faith. Corrections have been carried out on the materials and methods, grammar, spelling, syntax and formatting as suggested. These corrections could be seen in the manuscript with the track changes. Thank you. 1. Information on the experimental materials used in the study needs to be clarified. In page 5, line 92, the authors mentioned using 25 clones of C. nitida. Clones are individuals having similar genetic constitution. For a study aimed at looking at genetic variability in any trait, the use of clones does not make any sense since each of these individuals will have the same genotype, ergo the same phenotype. Even if variation for a specific trait is observed, the variation would not be significant. But looking at Table 1, significant variation in pod yield and nut weight and color among the clones have been reported. While yield and weight are quantitative traits that are affected by the environment, the data presented in Table 1 does not conform to the expected intra-clonal variation. To make matters more complicated, in page 8, line 116, the authors mentioned ‘grafting’ in relation to the 25 genotypes used in the study. It is unclear if the materials used in the study were scions from a single plant (clones) grafted to 25 different rootstock genotypes or 25 different scions grafted to the same rootstock genotype? This is important especially because one of the objectives of the study is identifying genotypes that can be used in breeding. If the materials used in the study are indeed grafts, the interaction between scion and grafts might have some effect in the traits examined and this should be determined prior to recommending genotypes that can be used as donors in breeding. Response The 25 clones means 25 genotypes of kola. We refer to them as clones because they were vegetatively propagated through grafting and planted as a research trial. The 25 genotypes do not have the same genetic constitution and their phenotypes are not the same. The cuttings of the 25 genotypes were grafted on a rootstock of one genotype or of same genetic background. Therefore, there was no rootstock and scion interaction. To make it clear to our readers, the term “clones” has been changed to “genotypes” and the paragraphs rephrased to make issues clear to our readers. The changes can be seen clearly in the manuscript with track changes. Thank you. 2. Page 4 line 67-73. The first and last sentence of this paragraph are contradictory. Response: Comment has been considered in revising the manuscript. The sentence has been rephrased to take out the contradiction. 3. Details about the methodology used for nitrogen, protein, carbohydrate and phenolic analysis should be provided. The readers should not have to go back to the cited papers for the full method. Response: Details of the methodology for nitrogen, protein, carbohydrate and phenolic analysis has been provided in revising the manuscript. Thank you. 4. The manuscript needs to be checked for several grammatical, typographical and spelling errors, formatting, as well as syntax to improve the overall readability of the paper. Response: This comment has been considered in revising the manuscript. The corrections on grammar, typographical and spelling errors, formatting and syntax was carried out throughout the manuscript. Examples: a. Page 3, line 45: Cola acuminate should be changed to C. acuminate Response: The correct one is Cola acuminata. b. Page 3, lines 49-50: This sentence is missing a period. Response: c. Page 3, line 51: “The kola industry offers” not “offer” Response: Thank you for the correction. The correction has been implemented. d. Page 3, line 59-60: Sentence can be paraphrased as “Bioactive compounds (phytonutrients) such as carotenoids and phenolic acids are health-promoting compounds that act against cardiovascular diseases and various types of cancer.” Response: Thank you for the correction. The correction has been implemented. e. Page 4, line 74: ‘bioactive compounds’ should be changed to ‘bioactive compound’ Response: Thank you for the correction. The correction has been implemented. f. Page 4, line 74: wrong spelling of ‘content’ and ‘greatly’ Response: Thank you so much for identifying the spelling mistakes. Corrections has been implemented. They were rightly spelled. g. Page 4, line 74: ‘ …contents of fruits are’ not ‘….is’ Response: Thank you for the correction. Correction has been implemented. h. Page 4, line 80-82: Sentence needs to be corrected. Wrong usage of grammar and sentence correction. Response: Thank you for pointing this out. The sentence has been rephrased and grammar corrected. This can be clearly seen in the manuscript with track changes. i.Page 5, line 99: Use the symbol for ‘degrees’ instead of superscripting the number ‘zero’ Response: Thank you for the correction. The correction has been implemented. The symbol of “degrees” was used. j. Page 5, line 102: Remove comma after April. Response: Thank you for the correction. The correction has been carried out. k. Page 8, line 116: The phrase “the grafted materials the 25 kola genotypes….’ Is unclear. Please paraphrase. Response: Thank you for the correction. Those phrases has been paraphrased to make them clearer. l. Page 11, line 169: Subheading title is unclear. Please paraphrase. Response: Thank you for the correction. The subheading has been paraphrased to make it clear. The corrections can be clearly seen in the manuscript with track changes. m. Page 11, line 171: wrong spelling of ‘between’ Response: Thank you for the correction. The Correction has been implemented. n. Page 11, lines 174, 176 and 177: What does the ‘()’ after the stat test mean? Response: It is a script language which translates the way functions are written in R. o. Page 16, lines 259-261: the five variable mentioned need not be in bold. Also, flavonoids and phenols should not be capitalized. Response: Thank you for the correction. The corrections were considered in revising the manuscript. p. Page 16, line 264: change ‘………flavonoids and phenols contents’ to ‘…..flavonoid and phenol contents’. Response: Thank you for the correction. The correction has been carried out. q. Page 17 line 271: Remove ‘an’ in ‘Breeding fruits with an enhanced nutritional…’ Response: The correction was considered in revising the manuscript. Thank you. r. Page 17, line 274: change has to have Response: The correction was considered in revising the manuscript. Thank you. s. Page 17, line 283: Put a space between ‘…nutraceutical contents’ and the citation [48] Response: The correction was considered in revising the manuscript. Thank you. t. Page 21, line 322: No space after the sentence and the period. Response: The correction was considered in revising the manuscript. Thank you. u. Page 21, line 323: Add a space between ‘in’ and ‘a’. Response: The correction was considered in revising the manuscript. Thank you. v. The manner by which P values were written were not consistent across the manuscript. Response: The correction was considered in revising the manuscript. The manner in which P values are written is now uniform across the manuscript. Thank you. w. Tables should be re-formatted according to PLoSONE specifications. Response: Comment was considered in revising the manuscript. Tables has been formatted according to PLoSONE specifications. x. The references should be checked for formatting and typographical and spelling errors. Response: Comment was considered in revising the manuscript. All references were listed and well formatted. Typographical and spelling errors has been corrected. The whole manuscript was revised and corrections were carried out. Corrections can be seen in the manuscript with track changes. 5. Please provide a high resolution for the Figure 2 and 3 Response: The resolution of the two figures were upgraded from a 300dpi resolution to >600dpi resolution. Figure 2 was divided into two parts (Figure 2-1 (A-F) and Figure 2-2 (G-J)) to be able to improve the resolution. This was used to effect changes in the figure number in the manuscript as well. The changes can be seen in the manuscript with the track changes. Attachments Attachment Submitted filename: Response to the reviewers.docx https://doi.org/10.1371/journal.pone.0242972.r006
13 Nov 2020 Decision Letter - Arun Jyoti Nath, Editor Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.] PONE-D-20-17736R3 Dear Dr. Nyadanu, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Arun Jyoti Nath Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0242972.r007
Formally Accepted
17 Nov 2020 Acceptance Letter - Arun Jyoti Nath, Editor PONE-D-20-17736R3 Genetic variability of bioactive compounds and selection for nutraceutical quality in kola [Cola nitida (Vent) Schott. and Endl.] Dear Dr. Nyadanu: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Arun Jyoti Nath Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0242972.r008

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