Arbuscular Mycorrhization in Colombian and Introduced Rubber (Hevea brasiliensis) Genotypes Cultivated on Degraded Soils of the Amazon Region

Round 1

Reviewer 1 Report

In my opinion , the manuscript entitled „Arbuscular mycorhization in Columbian and introduced rubber tree (Hevea brasiliensis) genotypes, cultivated on degraded soils of the Amazon region" requires several changes before being accepted for publication in Agronomy journal.

First of all, according to the Materials and Methods section I want to ask for few more details:

1. What was the criterion for sample selection for molecular analysis?
2. What was the concentration of DNA templates used for library preparation? The Authors wrote the volume but what were the concentrations? It could influence the interpretation of NGS results.
3. How many libraries were prepared and sequenced using MiSeq? How many reads were obtained from each library (raw reads and preprocessed reads used for further analysis)? Raw reads should be deposited in any repository, just for potential reanalysis in the future with other pipeline.

Result Section:

1.  Data presented on Figure 2 and Figure 3 should be arranged in the same order of analysed plantations (it's easier to compare the results of spore abundance in soil and the percentage of mycorrhizal colonization of the roots).
2. Line 261: were instead of where.
3. The Authors should consider adding a table with the plantation characteristics based on the molecular analysis (e.g. total number of AMF reads, total number of VT per plantation) and some general info like: age, plant genotypes. In my opinion this additional table will enable the reader to easily analyze the data, see the main differences between plantations even without careful reading the whole result part.
4. In Table S3 please add a family as a column to the table, just for better understanding (even for non-specialists). In the manuscript and Figure 5 Authors are analyzing the data on family level, data in Table S3 are more detailed.
5. Line 296: Authors mentioned a total of 419 089 Glomeromycotina sequences, although in Table S3 there are in total 415389 reads. Please correct one of these values.
6. Line 289: Authors wrote that 89 VT were assigned to Glomus. In Table S3 there are 90 rows corresponding to different Glomus spp. Please correct.
7. Table 2 could be moved to the supplementary data. It is rather a big table. All the important things are mentioned in the text.
8. Comment to lines 326-327: Less than 19% of VT were exclusive of a specific plantation type. This sentence could also suggest that the sum of specific VT was less than 19%, which is not true. I would try to avoid such misunderstanding. In fact, it is important to write that only in one plantation the specific VT number was so high (CTCG), the others showed around 5% of specific VT. It was the youngest plantation. Maybe it could suggest that the selection of best AMF was ongoing. Many species at the beginning and then after the selection the portfolio of AMF of different plantations or rubber tree genotypes is more or less the same. Maybe Authors could discuss this hypothesis?

Discussion:

1. Lines 398-400: Authors compared their molecular results to other studies in which other NGS techniques were used or even were not used. It is really hard to compare the results obtained using different sequencing techniques (different technology, different library preparation). Especially if the cited article also lacks some importants data (like the amount of DNA used for library preparations in Herrmann et al 2016). The results from molecular analysis should not be compared to the diversity analysis performed using traditional pipeline (like trapping in Pereira et al 2014). Even results generated during this study show differences between these two approaches. I am aware that it is hard to find references in which more or less the same techniques were used. Just please rephrase this part of the manuscript to show that You are aware that the cited results were obtained using different techniques. You could always suggest that according to the progress in molecular techniques' development there is a need for deep analysis, even of the areas seemingly known.

Author Response

Dear Reviewer 1: Please see the attachment.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Please find my comments and suggestions for the manuscript " Arbuscular mycorrhization in Colombian and introduced rubber tree (Hevea brasiliensis) genotypes, cultivated on degraded soils of the Amazon region.

I found it as an interesting article to read, however before it goes to publication process I suggest authors consider some major and minor comments to improve the overall manuscript ----

Major comments – The introduction needs critical editing as it's hard to follow and understand. I suggest reframing the whole introduction section--

Minor Comments

1. Line no- 34 --Between 2000 and 2014, rubber consumption increased 61.2%, Suggestion – if authors can include recent data for the consumption, it would be much impactful--
2. Line no- 57 to 59 – Grammatical errors, please rectify
3. Line no- 110 114 – Please reframe it's hard to understand
4. Line- 141- Expand AFA solution, and its composition or include the citation for the same.
5. Figure 2 and figure 3- If I got right, Y-axis in figure 2 is missing with the units. Please include.
6. Results – No comments
7. Discussion – No major and minor comments

Author Response

Dear Reviewer 2: Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The comments and suggestions on the manuscript entitled"Arbuscular mycorrhization in Colombian and introduced rubber tree (Hevea brasiliensis) genotypes, cultivated on degraded soils of the Amazon region have been well addressed by the authors and I found it satisfactory and recommend for further perusal. They have changed the sloppy introduction section, which is well appreciated; all other minor comments were also answered well. Thanks for the revision and for addressing the comments for the overall improvement of the manuscript.