Effects of Phosphorus Supply on the Leaf Photosynthesis, and Biomass and Phosphorus Accumulation and Partitioning of Canola (Brassica napus L.) in Saline Environment

Round 1

Reviewer 1 Report

General comments:

It is widely acknowledged that salt stress and P deficiency inhibit crop growth and yield,. However, the interactive effects of soil salinity and P nutrition have not been well documented for canola. This article is interesting as it explored the beneficial effects of P supply on alleviating the impairment of canola growth and yield formation induced by salt stress. The results, supported by data observations, suggested that P supply can improve the canola plant growth and seed yield in saline environment, by promoting the assimilate transporting from vegetative to reproductive organs and from pod shell to seed as well. The findings are significant and the article is worth considering for publishing in this journal, with minor revision and English polishing.

Following points if deemed for incorporation may be useful to increase the readability and more clear presentation of the manuscript:

Detail comments:

-- Statistical analysis: In this study, the Year is used as an additive factor in ANOVA. Though it is acceptable, but it is not optimal. The ANOVA Table 2 showed the Year effects on most of measures, suggesting it is better to do statistical analysis separately by year. The year x P rate interactions observed in the ANOVA Table 3 also suggested the performance discrepancy from one year to another for some of measures.

-- replace the term of “ANOAV” with “ANOVA” throughout the manuscript. It is abbreviation of “Analysis of Variance”.

-- Please cite your tables and figures as reference sources in the text, such as on Lines 107,  170, 193, 199, 212, 232, 245, 255, 268, 286 etc.

Lines 14-16: rewrite the sentence. “P supply is considered as an effective way to alleviate the damage of salt stress, however the knowledge of how P supply to promote plant growth  in saline environment was limited”.

Line 54, page 2: Change “compared with nitrogen, phosphorus (P)” to “ compared with N, P”, as the  terms of “nitrogen” and “phosphorus”  have been already abbreviated on Line 51.

Line 59, page3: Change “and P deficiency can intensity the damage of salt stress” to “and P deficiency can increase the severity of salt stress”

Line 65, page 3: replace “the availability of utilizable P” with “the available P” or “bio-available P”

Lines 80-82. Rewrite the last sentence: “These improvements conferred by P fertilizer supply under saline environment in aforementioned plants might suggest the same positive effects exist in canola.”

Lines 117-119: Comment: Did 270 kg N ha^-1 include the partial N applied as ammonium phosphate? If yes, you can rewrite the sentence: “In addition, N was supplemented as urea (46% N) to a rate of 270 kg N ha^-1, and K and B fertilizers as potassium sulphate (52% K2O) and borax (12% B) were applied to all plots at the rates of 75 kg K20 ha^-1 and 4.5 kg B 118 ha^-1, respectively.”

 Line 137, Page 4: change the second “ At flowering stage” to “At maturity stage”

Line 149 and also on the formula: replace “the sum der weight” with “the sum dry weight”

Line 182, page 5: change “were par with” to “ were comparable with”, same problem on Line 226 and Line 178

Lines 212 -218: Comment: these sentence describe the comparison of P accumulation between CK and treatment of 120 kg P2O5 ha^-1. The authors confused the term of “P accumulation” and “increment of P accumulation”. As the Figure 2 showed the P accumulation, I suggest the use “P accumulation’ instead of “increment of P accumulation”. Also, please double check the increase percentages, relative to CK.

Lines 277-279: Comment: rewrite the sentence. “The photosynthetic rate was consistently comparable in treatments received 60 and more kg P2O5 ha^-1 in two growing seasons, which was greatly higher than that in CK and low P supply of 30 kg P2O5 ha^-1 (Fig. 4c and 4d)

Line 289, page 12: correct the correction coefficient r = 0.987

Line 304: Replace “ P deficiency” with “salt stress”

Lines 324-329: re-organize the sentences of “…suggesting that P supply can help canola plants develop stronger root systems [35]. However, opposite results showed that the greater ratio of root to shoot was produced under P deficiency [17]. In other words, P supply resulted in more biomass partitioning in shoot rather than root. The reason for this unexpected difference may be that increasing P rate resulted in more P partitioning in root to support root growth.” For example, “… suggesting that P supply can help canola plants develop stronger root systems [35], in spite of the opposite results was observed in Li et al. (2009) that showed the greater ratio of root to shoot was produced under P deficiency [17]”.

Author Response

please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The study is interesting and was well conducted. The manuscript is well organized and the writing is clear. In my opinion, it deserves publication after some corrections:

 

A major flaw in the text is the reference to Tables and Figures. Instead of those references, it appears the sentence “Error! Reference source not found”. Please correct it and make appropriate use of reference to tables and figures in the text

You inappropriately use the word “leave”. You must replace it by leaf (singular) or leaves (plural) depending on the meaning of the sentence

 

L53-54 and L68. Correct the use of abbreviation of Nitrogen and Phosphorus. Use the abbreviated forms (N and P) since you previously describe these abbreviations

L77. Replace “P fertilizer additional” by the addition of P fertilizer

L167,192,194, 229. Replace “ANOAV” by “ANOVA”

L170. This sentence is incomplete, please correct it.

Tables 2-5. Use Capital letter for the first letter of each word and superindex for ha-1 in these tables. Tables 1-2 are correct

L268. Use capital letter for “p”

L289. The r value is wrong. I think that is 0.987

L335-343. There are no references in this part. You should add at least one.

L340. Use capital letter for “we”.

L341-345. These sentences are not clear as they are written as if they refer to results from your study but actually refer to other studies. You should rewrite this part

You should discuss more about why you choose the 120 dose. I suppose that this dose is more suitable because it produces similar positive effects as the 150 dose but to avoid over application of P it is more appropriate to use the 120 dose. Also, you should include some information about the long-term sustainability of P fertilizers in the discussion part.

References: You should carefully check the reference formatting and make some corrections. For instance, some references appear in capital letters. In ref. 8 the year is duplicated and neither the volume nor the pages appear. In ref. 10, delete the dot after Brassica. Ref. 41, Add a space after Rape

Author Response

Dear reviewer,

Thank you and reviewer very much for your constructive comments. We have considered them carefully and made a revision to our manuscript based on your suggestions. Revisions have been made.

Enclosed please find the detail responses to your comments.

Your sincerely,

Long Wang, Qingsong Zuo

 

Comment1: A major flaw in the text is the reference to Tables and Figures. Instead of those references, it appears the sentence “Error! Reference source not found”. Please correct it and make appropriate use of reference to tables and figures in the text

Response: the mistakes about the reference of Tables and Figures in the text had been corrected.

 

Comment2: You inappropriately use the word “leave”. You must replace it by leaf (singular) or leaves (plural) depending on the meaning of the sentence.

Response: we had replaced the “leave” with “leaf” or “leaves”.

 

Comment3: L53-54 and L68. Correct the use of abbreviation of Nitrogen and Phosphorus. Use the abbreviated forms (N and P) since you previously describe these abbreviations

Response: done as requested.

 

Comment4: L77. Replace “P fertilizer additional” by the addition of P fertilizer

Response: done as requested.

 

Comment5: L167,192,194, 229. Replace “ANOAV” by “ANOVA”

Response: we had replaced “ANOAV” with “ANOVA” in this manuscript.

 

Comment6: L170. This sentence is incomplete, please correct it.

Response: we had corrected this sentence.

 

Comment7: Tables 2-5. Use Capital letter for the first letter of each word and superindex for ha-1 in these tables. Tables 1-2 are correct

Response: tables had been revised as requested.

 

Comment8: L268. Use capital letter for “p”

Response: done as requested.

 

Comment9: L289. The r value is wrong. I think that is 0.987

Response: we had corrected the correction coefficient r = 0.987.

 

Comment10: L335-343. There are no references in this part. You should add at least one.

Response: we had added a reference in this part,

 

Comment11: L340. Use capital letter for “we”.

Response: this sentence had been rewritten.

 

Comment12: L341-345. These sentences are not clear as they are written as if they refer to results from your study but actually refer to other studies. You should rewrite this part

Response: wo had rewritten this part to reflect on our results.

 

Comment13: You should discuss more about why you choose the 120 dose. I suppose that this dose is more suitable because it produces similar positive effects as the 150 dose but to avoid over application of P it is more appropriate to use the 120 dose. Also, you should include some information about the long-term sustainability of P fertilizers in the discussion part.

Response: we had added a part to discuss why 120 kg ha^-1 is recommended.

 

Comment14: References: You should carefully check the reference formatting and make some corrections. For instance, some references appear in capital letters. In ref. 8 the year is duplicated and neither the volume nor the pages appear. In ref. 10, delete the dot after Brassica. Ref. 41, Add a space after Rape

Response: we had check all the reference and make corrections. 2014 is the volume of this reference, which also happens to be the year of it. Some of the references were published online without page numbers.

 

In addition, we added a reference for line79 “the addition of P fertilizer to saline soil improved root growth in sugar beet (Beta vulgaris L.)”.

Author Response File: Author Response.docx

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.