The Link between Mineral Elements Variation and Internal Flesh Breakdown of ‘Keitt’ Mango in a Steep Slope Mountain Area, Southwest China

Round 1

Reviewer 1 Report

This manuscript focus on the internal flesh breakdown (IFB) of ‘Keitt’ mango and its relationship with mineral elements variation. In general, Calcium (Ca) deficiency is considered the major reason for IFB development in mango fruit, but this manuscript showed fruit flesh with IFB symptoms had high, or low, or similar Ca levels compared to the healthy fruit flesh. This findings expanded the understanding of causes of IFB in mango fruit and opens another aspect of research related to IBF. In short, this study is novel and presented well. In my opinion, any changes in abstract, introduction, M&M, results, discussion and conclusion section is not required and suggest to accept the manuscript in the present form.

Author Response

Thank you very much for giving us an opportunity to revise and resubmit our manuscript.

Reviewer 2 Report

Please see my comments in attached pdf file. Try to improve your article according to my comments and other reviewers. The article need deep improvement. 

Comments for author File: Comments.pdf

Author Response

Dear reviewer

Thank you very much for giving us an opportunity to revise and resubmit our manuscript, which is now entitled, “Link between mineral elements variation and internal flesh breakdown of ‘Keitt’ mango in steep slope mountain area, Southwest China” (ID: horticulturae-1739296). We appreciate the positive and constructive comments and suggestions regarding our manuscript.

We have carefully considered your comments and have tried to revise our manuscript accordingly. 

Review’ comment 1: You can use the other word such as “Link” replace “Relationship” of the title.

Authors’ Response:  According to your suggestion, we have changed it, Line 1.

Review’ comment 2: The first sentence is not important, you can start with the main problem directly.

Authors’ Response:  According to your suggestion, we have revised them, Line 23 – line 24.

Review’ comment 3: keywords, try to use different words than title.

Authors’ Response:  Thank you for the comment.  We have revised them, Line 42.

Review’ comment 4: “Among these external factors, most research reported that mango IFB is closely associated with deficiency of one or more mineral nutrients in fruit, and low calcium (Ca) content in fruit is widely believed to be the key factor leading to IFB development, and the disorder is also called as “Ca deficiency symptom” However, increasing Ca input through foliar and/or fruit application is not always an effective measure to prevent IFB in mangoes.” ---long and unclear sentence, please rephrase it.

Authors’ Response:  Thank you for the comment. We have rephrased it, line 64- line 66.

Review’ comment 5:  Muhammad et al. [5] found that pre-harvest spray or post-harvest fruit with 4% calcium chloride (CaCl₂) and 1% magnesium chloride (MgCl₂) solution reduced the incidence of IFB in mango (‘Samar Bahisht Chaunsa’), but 1% CaCl₂ pre-harvest treatment did not yield notable effects.—not correct sentence

Authors’ Response:  Thank you for the comment. We have rephrased it, line 71- line 73.

Review’ comment 6: Please provide the monthly average temperature and RH.

Authors’ Response:  There are many different factors impact the incidence of internal flesh breakdown (IFB) during mango production. However, according to our previous investigation, we find that long-term unreasonable fertilization is the main cause of IFB, which imbalances the nutrient elements in mango fruits, inducing internal flesh breakdown. Although the climate varies could influence the incidence of IFB, it is not the major cause. In addition, the incidence of IFB in different orchards could not vanish due to the climate varies. Therefore, the impact of climate varies on the incidence of IFB is not taken into consideration in this study. The main object of this study is to analyze the relationship between IFB and nutrient elements, and then to find the main nutrient element which causes the incidence of IFB. So, we don’t record the average temperature and RH.

Review’ comment 7: The position of the leaf and fruits sampled.

Authors’ Response:  From each tree, 15 expanded healthy leaves from bearing and non-bearing branches, and 20 fruits were sampled 80 days after full bloom (the second fruit fast expansion stage) and 150 days after full bloom (fruit commercial maturity stage) from four directions (east, south, west, and north) around the tree in the 2020 fruit season, respectively. Line 129 -133.

Review’ comment 8: Analytical methods, please provide the reference for every parameter.

Authors’ Response:  The analytical methods of mineral nutrients  were based on the method of  Bao, S. D. “Soil Agrochemical Analysis Tird Edition. China Agriculture Press, Beijing. 2000; pp. 432-470.”

Review’ comment 9: You have to present full analysis.

Authors’ Response: In present study, we think that the soil available Ca (ACa) and Mg (AMg) can reflect the status of soil Ca and Mg.

Review’ comment 10: These results indicate that IFB development is not always the result of low total Ca concentrations in mangoes.

Authors’ Response: Thank you for the comment. We have revised it, line 210 - line 212.

Review’ comment 11: Figure 5, what these color meaning?

Authors’ Response: The color of the Figure 5 represent the Ca content of individual orchard. We have added the explain in line 215 – line 217.

Review’ comment 12: Discussion need to improve?

Authors’ Response: Thank you for the comment. We have revised it, line 298 - line 302, line 308 -  line 319, line 321 -326, line 336 – line 338, line 345 – line347, line 375 –line 377, and line 393- line 400.

 

Reviewer 3 Report

 

Mango fruit is a popular subtropical and tropical fruit and China is the second-largest mango producer in the world after India. Internal flesh breakdown which is considered as a physiological disorder in mangoes often occurs during pre-harvest ripening and post-harvest storage of fruit. It is very important to investigate the extent of physiological disorders in mango orchards and how changes in the mineral nutrients of fruit flesh, leaves and soil affect fruit flesh breakdown. The topics of the article are very important for mango fruit growers.

Specific comments:

Line 92. “fruit transcription rates” – what do you mean? Maybe “respiration rate”?

In molecular biology, a transcription factor (TF) is a protein that controls the rate of transcription of genetic information from DNA…

Line 109. “…‘Keitt’ mango is the leading commercial variety…”, but in line 147 you wrote “…cv. Keitt…”.  It’s mean cultivar?

So, ʽKeittʼ is a variety or cultivar of mango fruit?

A variety refers to a variation within a plant species that develops naturally in the environment.

A plant cultivar refers to a variation within a plant species that has been developed by a human horticulturist through controlled plant breeding, as opposed to occurring naturally.

Probably it’s cultivar name.

Line 143-144. “Soil types in the study area are mainly the red and yellow-brown soil”.

You have to describe the soil of the study area according to the International soil classification system.

Line 151-152. “From each tree, 15 expanded healthy leaves, and 20 fruits were sampled…”

It is necessary to specify the size of the final samples.

Line 172-173. “…phosphorus (P) using the molybdenum blue method…”

Molybdenum blue phosphorus method in conjugation with UV-visible spectrophotometer is used to determine the amount of phosphate.

Line 173. „...and potassium (K) by flame photometry.”

You have to explain analysis methods more accurately.

Line 188. “…duncan’s multirange test at p-values < 0.05”. “Correlation was calculated using pearson’s correlation coefficient…”

David B. Duncan and Karl Pearson was real person, so test and coefficient title must be written in capital letters: Duncan multirange test and Pearson correlation coefficient.

Line 197. Part “Results” cannot be started from the figure, there must first be text with a reference to the Figure 3 and then the figure.

For the Figure 3 suggest putting numbers on the columns in figure to make it clearer.

Line 209-211. „To investigate the mineral elements in fruit flesh associated with the development of IFB, we measured the N, P, K and Mg content in the flesh of healthy fruit and fruit with IFB in the 100 sampled orchards”. But in Line 225-226. “…the potential differences in Ca content between healthy and IFB fruits from 76 orchards were analyzed.”

It's not clear why Ca content you analyzed of fruit and leaves from 76 orchards if you collected samples from 100 representative commercial mango orchards? It needs to be clarified.

Line 218, Figure 4 and Line 264, Figure 8, Line 275, Figure 10. Mineral content must be in mg kg^-1.

Line 232. In which units the amount of Ca is given in the Figure 5?Line 248. The graphs in Figure 7, Figure 9 and Figure 11 are so small that nothing can be seen. What’s the point of them? Maybe it is better to present the data in a table?

Line 255-256. “To examine the mineral elements in leaves involved in IFB development, we compared the differences in leaf N, P, K, Ca and Mg concentrations between samples from 76 orchards”. Why not from 100 orchards?

Line 272. Section 3.4 cannot be started from the figure, there must first be text with a reference to the Figure 10 and then the figure.

 

Author Response

Dear Editor

Thank you very much for giving us an opportunity to revise and resubmit our manuscript, which is now entitled, “Link between mineral elements variation and internal flesh breakdown of ‘Keitt’ mango in steep slope mountain area, Southwest China” (ID: horticulturae-1739296). We appreciate the positive and constructive comments and suggestions regarding our manuscript.

We have carefully considered the reviewers’ comments and have tried to revise our manuscript accordingly. In the following pages are our point-by-point responses to the comments and suggestions from you and the reviewers. Additionally, please find attached the revised manuscript, which we would like to re-submit for your kind consideration. We look forward to hearing from you at your earliest convenience.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

Dear authors,

Thank you for your efforts to improve the MS. A lot of modification was done. However, some comments you didn’t consider or have other view. My comments are:

1- You mention that (According to the United States 119 Department of Agriculture (USDA) soil classification system120(http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_051232.pdf), the soil of 121 the study area is a reddish brown loam soil derived from old alluvium).

But you have to analysis your experiment soil since you study the link between IFB and nutrient elements. Maybe you find any other elements (low or high) which could affect IFB. Please try to present it.

2- My previous comment (before you use ANOVA you have to run normality test to ensure that all your data have normal distribution. Did you do that?)

you don’t have reply. Please revised.

3- You mention that (The main object of this study is to analyze the relationship between IFB and nutrient elements. So, we don’t record the average temperature and RH).

But, in my opion, the temperature is normally affect the absorption of elements from the soil. Also, Ca absorption is affected by the humidity, temperature, transpiration, and evaporation from leaves because its immobile element. Thus, its important to show that. You can find these data easily from any climate station in the location of study.    

All the best,

Author Response

Response to Review’ Comments

Review’ comment 1: But you have to analysis your experiment soil since you study the link between IFB and nutrient elements. Maybe you find any other elements (low or high) which could affect IFB. Please try to present it.

Authors’ Response:  Thank you very much for you suggestion. We have present the basic characteristic of experiment soil based on the results of China’s second national soil survey [National Soil Survey Office (NSSO)] in the early 1980s, in line 120 – line 126. Because the data from NSSO has not been open, so we don’t attach the references. Moreover, the second soil survey did not investigate the contents of soil Ca, soil Mg and soil micronutrients (Fe, Zn, B, Cu).

Review’ comment 2: My previous comment (before you use ANOVA you have to run normality test to ensure that all your data have normal distribution. Did you do that?)

Authors’ Response:  According to your suggestion, we have revised them, Line 175 – line 176.

Analysis of variance (ANOVA) was performed to detect the statistical difference using Duncan’s multirange test at the significance levels of p < 0.05 (*) and p < 0.01(**).

But, we do not run normality test of our data.

Review’ comment 3: But, in my opion, the temperature is normally affect the absorption of elements from the soil. Also, Ca absorption is affected by the humidity, temperature, transpiration, and evaporation from leaves because its immobile element. Thus, its important to show that. You can find these data easily from any climate station in the location of study. 

Authors’ Response:  Thank you for the suggestion. Temperature and RH have been added, Figure 3, Line 128.

Reviewer 3 Report

Thank you for taking note of the comments and correcting them. Wish you success in your further research

Author Response

Thank you very much for your help.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Dear Authors, Thank you for selecting the significant topic of physiological disease of important cash crop as mango is. I would like to say that graphical presentation of your results is really outstanding and Discussion section is also a very strong point of your manuscript. Reviewer as non-native English speaker is not competent enough to evaluate language level but some mistakes are eveident and you should improve it by inspection by educated native English speaker. As far as Reference section is concrned I am not sure if you cited well position no 14 in line 178. The other suggestions are marked in the text.

Comments for author File: Comments.pdf

Reviewer 2 Report

Relationship between mineral elements variation and internal flesh breakdown of ‘Keitt’ 2 mango in steep slope mountain area, Southwest China

The article titled “Relationship between mineral elements variation and internal flesh breakdown of ‘Keitt’ 2 mango in steep slope mountain area, Southwest China” is based on the field experience with the main aim to research the most optimal technology and the influence of nutritional elements and its ratio on IFB appearance in mango orchards. The manuscript is quite interesting and acceptable for publication, but I suggest ad several corrections.

Line 30: Please just put coma ( , ) instead of sign ;

Line 30: Please just delete sign “ ; “  before  word:  „and” (in several places in manuscript).

Line 40: Please just delete sign  ;  before  and

Line 72: Instead part of sentence: However, internal flesh breakdown (a physiological disorder) in mangoes often occurs during pre-harvest ripening and post-harvest...

Please put:  However, internal flesh breakdown, which is considered as a physiological disorder, in mangoes

Line 108: maybe the word Investment sounds better than the word "money"

Line 305: ‘Keitt’ mango showed a high occurrence of IFB since it that 76 % of the orchards were affected.

Kind regards

Comments for author File: Comments.pdf

Reviewer 3 Report

Suggestions in the manuscript.

Comments for author File: Comments.pdf

Reviewer 4 Report

General comment:

This paper reports on a one-year study on the indidence of internal flesh breakdown (IFB) in 100 orchards of sourthwest China. Two to three years of experimentation are necessary to support conclusions because the climate varies between years and could impact differently the incidence of IFB. The paper lacks hypotheses to justify the methodologies and come to a robust conclusion. Meteorological conditions should be reported In more details due to their high impact on IFB incidence. The methodology is poorly described (chemical analyses) or presented at the wrong place (statistics). Simple correlation and one-way ANOVA analyses are conducted on multivariate data while it would require conducting multivariate analyses. The authors focused on macronutrients, but micronutrients such as boron may be of utmost importance to strengthen the fruit. Excessive N fertilization tends to dilute micronutrients in the plant and soften the leaf and the fruit. Nutrient report is thus little informative. This study is exploratory study and requires more data to support a robust conclusion. I suggest conducting the experiment for 1-2 more years, quantify micronutrients in fruit, leaf and soil, and use tools of multvariate analysis to fully capture the relationship between plant nutrition and IFB.

Specific comments:

1. 69-77: false start. Show first the importance of mango production in the world, then in China and Hainan. Hence move l. 98-106 to introduction. Indicate specific properties of mango flesh that are attractive to the consumer. Finally, focus on the deterioration of mango flesh through IFB and document the importance of the problem in terms of economic loss around the world and in the region, not just in general terms. Since you mentioned ‘farmers’, indicate the average size of the farms that must impact on farmer’s income.
2. 71: mention the acronym after ‘internal flesh breakdown’ (IFB). Thereafter, you can use IFB. If IFB starts a sentence (l. 75, 76), you should write ‘The IFB’.
3. 81, 85, 103, 108, 142: ‘humidity’ is too general: do you mean air relative humidity, rainfall, irrigation, soil moisture content?

l.86-90: what about boron?

1. 92: transcription?

Figure 1 could report farm size and plantation density. 

1. 127-131: you mention the objective of the study but you do not present any hypothesis for the research. Hypotheses are needed when reporting results and to support conclusions on whether they were accepted or rejected.
2. 153: these are resuts from a single season (2020).
3. 158: what absorbent paper? Is there a risk of contamination?
4. 160-161: how many points?
5. 162: what do you mean by ‘to avoid fertilization’?
6. 164: the soil sample rather than plant residues and stones was ground and sieved.
7. 165: why two sieves (1 mm and 2 mm)? In general, 2-mm sieve is used?
8. 168-170: were P and K digested using the Kjeldahl method?
9. 173: provide a referencce for AM.
10. 174-176: what was the extraction method for available P and K?
11. 176-178: you determined total Ca and Mg in the soil? Why did'nt you use a soil test method? You mention ‘available’ Mg and Ca in Figure 10 and l. 268, but you do not indicate the extraction method used to measure nutrient availability in soils.

How did you evaluate IFB? Visually? By machine vision? Other means? In terms of size of the damage, firmness, color, …?

Add a section on statistical analysis and software in M&M, not in the Results section and in Figures.

1. 187-192: how did you obtain those percentages?
2. 197-199: move to the M&M section.
3. 200, 201, 202…: provide a probability level for ‘significantly’.
4. 204: the correlation coefficient is extremely low and the probability level for rejection is also extremely low. There is an apparent contradiction here. Explain.

Figure 4: indicate the units for HF and BF in the graphs. The BF was not mentioned in the M&M section. How did you detemrine BF? What the BF unit?

1. 212: you mention 76 orchards but you monitored 100 orchards (l.147, 236). Why did you drop 24 orchards?

Figure 7: statisticians suggest using logarithmic transformations for percentages and pairwise ratios to control disparity from normality. For five nutrients analyzed (and presented in Figure 7), you could compute 10 pairwise ratios. Why do you show just three pairwise ratios?

Figure 9: why didn't you present relationships between IFB and pairwise ratios as in Figure 7?

1. 298-302: move to introduction.
2. 301: this study requires more to qualify as a systematic study.
3. 308-311: what is new in this finding?
4. 313: believe? Accept or reject hypotheses would make a more suitable basis for discussion.

Discussion

You could discuss your results in relation to results reported in the literature, not just refer to general statements in the literature (which would be suitable in the introduction).

Discussing simple correlations is extremely confusing without clearly posing plausible hypotheses beforehand. It is even more confusing because nutrient interactions cause interpretation biases. Pearson (1897) warned against ‘false correlations’ and Aitchison (1986) warned against ‘resonance’ in compositions. Egozcue et al. (2003) suggested using isometric log ratios to run multivariate analysis on compositions (here as a means to tackle imbalance among nutrients).

1. 370: this is not a long-term study. What were the initial conditions?

Conclusion

This is not a conclusion. It should be moved to the discussion section. Conclusions should be set in relations to the hypotheses.

1. 389: speculative? If this is a hypothesis, mention it at the end of the introduction.