Cinnamom verum Plantations in the Lowland Tropical Forest of Mexico Are Affected by Phytophthora cinnamomi, Phylogenetically Classified into Phytophthora Subclade 7c

Round 1

Reviewer 1 Report

Cinnamon is an important tree producing aromatic spice in Mexico; however, symptoms of dieback have been observed in 12-year-old cinnamon plantations cultivated in an agroforestry system in the state of Veracruz. The author claimed that P. cinnamomi subclade 7c was responsible for the symptoms observed in lowland cinnamon plantations in Mexico. Thus, it is suggested that this phytopathogen is a new threat for Cinnamon growers, and implement management strategies are recommended to avoid its introduction in nurseries or in new plantations that could be susceptible to this pathogen. However, several small issues should be addressed properly.

1.      In line 219, “3.1. Isolation, Characterization, and Identification of Causal Agent of death regressive, chlorosis, crown, and root rot of Cinnamomum verum”, all words in the sentence should be in lowercases, except for the first one “Isolation”.

2.      Also in line 219, “3.1. Isolation, Characterization, and Identification of Causal Agent of death regressive, chlorosis, crown, and root rot of Cinnamomum verum”, but there is no “3.2……” in the following contents, only “3.1.1. Phylogenetic reconstruction” in line 239 and “3.1.2. Pathogenicity tests” in line 262. Should the paragraph structure of “3. Results” be modified or revised?

3.      The authors suggest that implement management strategies are recommended to avoid its introduction in nurseries or in new plantations that could be susceptible to this pathogen, but what are exactly these strategies? These strategies should be provided in detail.

Author Response

Reviewer 1

Thanks for the comments and suggestion.

I inform you that each of your comments was addressed to substantially improve the work presented. The attached file shows the changes marked in green.

Author Response File: Author Response.pdf

Reviewer 2 Report

In general, this is a well-written manuscript summarizing interesting and important research but it requires some changes.

The study is well conducted using morphological and molecular methods for detecting and identifying Phytophthora cinnamomi. Pathogenicity tests were done and Koch’s postulates were fulfilled.

 The manuscript suffers from some weaknesses, which I commented in the pdf file.

 The English usage and grammar in this manuscript are very poor, it would be worthwhile to make use of some language editing facilities.

Comments for author File: Comments.pdf

Author Response

Thanks for the comments and suggestion.

I inform you that each of your comments was addressed to substantially improve the work presented. The attached file shows the changes marked in yellow.

The dramatic quality of the manuscript has improved remarkably. It is worth mentioning that the work was reviewed by a native speaker of the English language (USA) to comply with this observation.

Line 80-84. It was recommended to move the paragraph to Discussion.

Answer

We decided to keep this paragraph and not move it to Discussion, we believe that it is an important part of the introduction and it introduces the reader to the problem that this pathogen causes in the cultivation of cinnamon in the world.

Line 241. Authors mention one isolate here and two isolates in the next paragraph. Clarify this.

Answer

This confusion is clarified in the paragraph, please verify.

Line 277. This part of the work is confusing and misleading. Two independent isolates should be included in the phylogenetic analysis. Sequencing of the ITS region is enough for the identification of the reisolated strain.

Answer

We believe that the phylogenetic analysis is very good and sufficient for the objectives of the present investigation. In addition, both sequences are found in the reconstructed Bayesian Phylogenetic Tree, the strain PC-C4 (MN497236) originating from the study area of Veracruz, and the strain PC-C5 (MN497237) recovers from Koch's postulates.

Author Response File: Author Response.pdf

Reviewer 3 Report

Cinnamon has a great significance in different regions of the world, being used as spice, flavoring and coloring. Increasing knowledge on the spectum of pathogens affecting the tree is important for both scientific and practical purposes. So, the paper is timely and scientifically sound. At the same time, I would like to make some comments on the MS text and methods used:

1. Page 2, lines 71-74: I believe, this sentence could be changed to (for example): "P. cinnamomi is an important pathogen of horticultural crops, affecting 319 genera in 90 famolies, procipally forest trees and found in 56 countries of tropical and subtropical regions."

2. Page 2, line 83, reference 20: should be in square, not round brackets.

3. Page 2, lines 84-85: may be: C. verum is the only dominant species of cinnamon cultivated in Mexico, and it has been reported as a host of P. cinnamomi."

4. page 3, line 99: "east of Mexico" or "eastern Mexico" instead of "eastern of Mexico"

5. Despite the fact that ITS has been considered as a 'golden standard' of fungal molecular phylogeny, it would be interesting to use another marker for phylogenetic reconstruction (optional)

6/ It also would be useful to include some references devoted to molecular (e.g. PCR) assays for identification of P. cinnamomi (optional).

Anyway, I believe the paper can be accepted after minor revision, but the text ought to be thoroughly read to avoid grammar and stylistic mystakes.     

Author Response

Thanks for the comments and suggestion.

I inform you that each of your comments was addressed to substantially improve the work presented. The attached file shows the changes marked in blue.

The dramatic quality of the manuscript has improved remarkably. It is worth mentioning that the work was reviewed by a native speaker of the English language (USA) to comply with this observation.

Reviewer Comments

Although ITS has been considered a 'gold standard' of fungal molecular phylogeny, it would be interesting to use another marker for (optional) phylogenetic reconstruction.

Answer

We believe that the Bayesian phylogenetic analysis is very good and sufficient for the objectives of the present investigation.

Author Response File: Author Response.pdf