Crossbreeding Rootstocks Improve Nitrogen Efficiency of Grafted Watermelon by Inducing Leaf Physiological and Root Morphological Responses
Round 1
Reviewer 1 Report (New Reviewer)
I consider it relevant that the importance of nitrogenous fertilizer in food production and the low efficiency in its use are indicated. In addition, the effect of heterosis on plant growth is analyzed. Grafted plants significantly improved shoot and root growth and main stem length compared to autografted plants with high and low doses of N.
It seems clear to me that among the grafting combinations, plants grown in high N supply generally had higher yields in shoot and root growth and biomass production than plants grown in low N conditions.
In addition, the effect was expressed in total number of leaves, leaf area, photosynthetic rate and leaf chlorophyll content.
The same text is repeated in the document in lines 332 to 334 and in 362 and 364. I believe that it should be changed in one of the two places. Likewise, the conclusions repeat similar text indicated in the abstract. I suggest they be derived from the results.
Author Response
Please find the enclosed document.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
The author presented a manuscript Crossbreeding Rootstocks Improve Nitrogen Efficiency of Grafted Watermelon by Inducing Leaf Physiological and Root Morphological Responses. Although the manuscript has all the precedents for an interesting paper, further deep analysis and discussion are lacking. Therefore, my recommendation is that the manuscript cannot be accepted for publication as it stands.
My first concern is about the methodology and the depth of the discussion.
1.- The author indicated that “Between complete renewals of the nutrient solution (7 days intervals), all nutrients were replaced when the N concentration of the nutrient solution in the 3.0 mM N rate pots fell below 0.3 mM”, Why wait until the high nitrogen treatment reaches the level of the low nitrogen treatment?
2.- The author also indicated, “CaSO4 was applied (1.35 mM) only into the low N treatment”, without indicating whether or not a chemical balance study of the nutrient solution was carried out. What happened with sulfur in the nutrient solution?
3.- For photosynthesis measurement, why use 1000 µmol m−2 s−1 for measurement?, if the plants grew to 400 µmol m−2 s−1?.
4.- For photosynthesis measurements, Why measure photosynthesis in the third and fifth week if the experiment lasted 6 weeks?
5.- The author must specify at what time (day) measured with SPAD since the author indicates during the growth period!
6.- The discussion is based only on comparing results with other publications, without suggesting or proposing some mechanism that explains the results obtained or why the authors are observing these changes in the measured parameters.
7.- The conclusion should be improved and not summarize the results obtained.
Minor points:
1.- Some English language problems need to be corrected. For example, Objective line 10 “The aim of the study was to evaluated….”.
2.- Also, line 276 “The capable rootstocks that has vigorous root system improves enhance water and ion uptake from the soil solution, and transfer to aboveground plant parts. It is improves or enhance? It is have no has!
3.- Lines 198-202, please improve the sentence since it is very long!.
4.- Line 85, the first time this abbreviation is spelled, and then use NUE.
5.- The author should add a figure to clarify the experimental design and measurements.
Author Response
Please find the enclosed document
Author Response File: Author Response.pdf
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
This study tested the effects of different rootstocks on the growth and N absorption capacity of watermelon grafted seedlings, which has good application value. However, the experimental design was not repeated enough, and the processing and expression of experimental data were still insufficient. It is hoped that the authors can make serious modifications.
Line 101-108
The description of disease resistance of watermelon cultivars is better moved to the introduction section.
Line 111
“cleft grafting”-It can be describe the grafting method simply or show a picture of grafted seedlings.
Line 121
‘air pump’- Better to add details, such as air output.
Line 128 “Ca(NO3)2 was used as N source” So the concentration of Ca2+ is going to be different for different N treatments. How can you be sure the results aren't affected by different concentrations of Ca2+?
Line 128-131
All numbers in the molecular formula should be subscript.
Line 134
“Plant growth was measured by using three uniform plants from each replication.” Whether the experiment was a randomized experimental design? It should be a random selection rather than an artificial selection of uniform plants. And three plants per treatment is too few. Is each plant a repeat group?
Line 143
How is N content measured in various parts of the plant? Kjeldahl method?
“mg N g DW-1” Verify that the unit is correct.
Line 211
Table 1-Please use a three-line form (for all tables),
Why only Low N has F-test?
Line 279
Table 2. For nitrogen use efficiency & BPE , the gram units are recommended.
Line 348
Figure 1 -The “Graft combinations” in abscissa, a simplified abbreviation can be devised.
Why are the numbers at the bottom right of each figure 1A, 1B, 1C, etc.?
The description of F-test in the figure is not clear enough. Please use proper punctuation marks.
Are there photos and morphological analysis of plant growth differences after different treatments? It would be more beneficial to prove the experimental conclusion if it could be added in the result part
Line 451-464
The description of the experimental design need not appear again in the conclusion.
Author Response
Dear Reviewer,
Please find the attached document which is the Response to Reviewer1.
Author Response File: Author Response.pdf
Reviewer 2 Report
The study evaluated whether grafting could improve nitrogen use efficiency (NUE) of 9 watermelon through examining the changes induced by crossbreeding rootstocks.The test data is detailed, the results are reliable, and the writing is fluent.
There are several issues that require reorganization:
The author chooses several watermelon materials that are resistant to fusarium wilt, but this study did not design a disease-resistant experiment.
The author uses several cross combinations as rootstocks for experiments, and the author should pay more attention to the role of heterosis. Hybrids can fully improve the nitrogen utilization efficiency of plants and roots due to their own heterosis.
Author Response
Dear Reviewer,
Please find the attached document which is the Response to Reviewer2
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The main findings of the research
The current study entitled “Crossbreeding Rootstocks Improve Nitrogen Use Efficiency of Grafted Watermelon by Inducing Leaf Physiological and Root Morphological Responses” is an interesting and novel topic in watermelon research and breeding programs. The study evaluated whether grafting could improve watermelon's nitrogen use efficiency (NUE) by examining the changes induced by crossbreeding rootstocks. The author summarized that the efficiency of nitrogen uptake after grafting increases in watermelon, influencing agronomical, morphological, and physiological characteristics, which can be improved by crossbreeding rootstocks (heterosis). The authors have provided detailed and reliable results, and the statistic applied is satisfactory.
Final decision
The author responses to the last comments are admirable and satisfactory. The manuscript is well designed, and the data provided in the manuscript is complete and accurate. Currently, I am endorsing the manuscript and suggesting to authors to read the entire manuscript carefully and check for English grammatical errors.
Final Suggestions
Following are mistakes that need to be corrected
- The same sentence is repeated two times in lines 127-128 and 138-139.
- Lines 141-149, the instrument used for measurements is not mentioned, how author measured the weight (FW/DW) of leaves root and shoots.
- Line 158-161 is not clear. Explain the methodology of grinding of samples and measurements.
Author Response
Dear Reviewer 3,
Please find the enclosed pdf file as the response to reviewer.
Best regards,
Author Response File: Author Response.pdf
