Impact of PGPR Formulations Combined with Exogenous IBA Levels to Enhance Root Capacity in Poinsettia Cuttings
Round 1
Reviewer 1 Report
The article presents information of interest to increase the rooting of the plant, however, the combination of AIB with the PGPR used did not consistently induce rooting. It is advisable to use other bacteria, such as Azospirillum.
Author Response
Dear Reviewer,
First of all, thank you very much for your valuable suggestion. As a matter of fact, there are many successful literatures on plant growth and development of Azospirillum bacteria. Based on the results from previous studies and some biochemical test results, bacterial strains with very good nitrogen fixation and phosphorus solvent properties were selected for use in the experiment (Pantoea agglomerans, Paenibacillus polymyxa, Bacillus subtilis, Bacillus megaterium, Pseudomonas putida, Bacillus megaterium, Kluyvera cryocrescens and Pantoea agglomerans). The properties we targeted for the bacteria belonging to the Azospirillum strain/s in our collection were not sufficient, therefore they were not selected. We also continue to isolate bacteria from new host plants from different locations and experiment areas. We wish to continue our research with these bacteria and Azospirillum bacteria.
Reviewer 2 Report
The manuscript entitled "Impact of PGPR formulations combined with exogenous IBA levels to enhancing root capacity in poinsettia cuttings" is an original manuscript that falls into the scope of the journal. The manuscript could be accepted for publication after moderate revisions mentioned on the attached pdf.
English used need significant improvements.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 2 Comments
Point 1: The manuscript entitled "Impact of PGPR formulations combined with exogenous IBA levels to enhancing root capacity in poinsettia cuttings" is an original manuscript that falls into the scope of the journal. The manuscript could be accepted for publication after moderate revisions mentioned on the attached pdf.
Response 1: The attached pdf has been carefully studied.
- The title has been revised: “Impact of PGPR formulations combined with exogenous IBA 2 levels to enhance root capacity in poinsettia cuttings”
- In the abstract, what the formulations contain is explained. It has been revised as follows: ((BI) formulation 1 (Paenibacillus polymyxa TV-12E + Pseudomonas putida TV-42A + Pantoea agglomerans RK-79), (BII) formulation 2 (Bacillus megaterium TV-91C + Pantoea agglomerans RK-92 + Bacillus subtilis TV-17C), (BIII) formulation 3 (Bacillus megaterium TV-91C + Pantoea agglomerans RK-92 + Kluyvera cryocrescens TV-113C) and (BIV) formulation 4 (Bacillus megaterium TV-91C + Pantoea agglomerans RK-79 + Bacillus megaterium TV-6D).
- Two sentences in the abstract have been deleted. These sentences were as follows: "The study was consisting of conducted using two factor experimental design of 20 treatments ar-ranged in Completely Randomized Design. The 20 treatments were tested and each treatment was repeated as much 3 times."
- The sentence in the abstract has been revised as follows. “This study provides positive feedback on fertilization of stock mother plants with PGPR to provide sprout production by cuttings technique”.
- The last paragraph of the introduction is reworked.
- The growing medium mentioned in lines 107 and 108 is the mortar used to grow the stock mother plants (Figure 1A, B). What is seen in the photos is the medium used for rooting the cuttings. So it is perlite (Figure 1 C,E,F). It was added “The main components of the peat (Peat Klasmann TS1 (Peat Moss)) used are decomposed white sphagnum peat and frozen black sphagnum peat, EC; 40 mS m-1 (+/-25%), pH value (H2O); 5.5–6.5 and nutrient content (NPK fertilizer 14-10-18) 1.5 kg m-3 and sterile. The pumice used has the characteristics of 45-90% porosity, water absorption 30-70 wt%, pH value 7.0-7.3 and water soluble matter amount (wt%) ≤ 0.15.”
- All suggested changes in section Materials and Methods have been made. The entire article has been re-examined.
8 . Table titles and parameter names and details have been revised.
- The discussion section has been reworked.
- New references have been added.
***All changes made are indicated in red in the attached document.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Line 12 – The Abstract should be thoroughly revised. In this form is difficult to read, with too many details. Please explain all abbreviation (IBA, NR, NAS, etc) when they are first time used.
Line 80 – what do you mean by phosphate solvents?
Line 90 – please emphasize the novelty of your work at the end of Introduction section.
Line 91 – please revise the following formulation - feeding the rootstock plants with the bacterial formulation.
I suggest a serious English language evaluation of the introduction. In this form is not acceptable.
Line 102 – it is not relevant to have the Figure 1-d photo with IBA flasks.
Line 118 – What Nitrogen and Phosphate represent in the Table 1 head? Also, it is not clear what Strong +, W: Weak +; +: Positive, -: Negative means? Why two strains of Bacillus megaterium with similar PGP traits were selected? The authors should explain in the manuscript why PGPR strains isolated from different plants were selected to be used on Poinsettia plants?
Line 128 – the authors must present in the manuscript the reason of choosing 3 PGPR strains with similar PGPR traits for each bio- formulation. Also, information about the culture medium and growth conditions must be presented – one culture medium for all strains? Why was sugar added to the bacterial suspensions? This added sugar can influence the plant growth? How 1 × 108 CFU ⋅ mL−1 dilution was obtained by assessing bacterial density spectrophotometrically?
Line 143 - plastic pots and the growing medium were sterilized before adding cutting inoculated with PGPR formulations? If not, a serious question appears related to the epxeriments.
Also, the growth of PGPR on cuttings were monitored after inoculation? If not, how can we be sure that the inoculants survived on plant material – especially for such a long period of time – 1 year and also how can we be sure about the effects on plant nutrition?
Line 195 – The authors are using this form: Bacteria formulations - Used to provide plant nutrition to stock mother plants – how can they be sure of that? There is any experimental evidence for that?
The main goal of the paper remains unclear for me. From my point of view, the paper should be about IBA influence on rooting performance of poinsettia cuttings, and not about PGPR influence on mother plants nutrition (for this, experimental evidence is missing).
Author Response
Response 1: - The abstract has been reworked. It has been revised in line with the recommendations of reviewer-3 and other reviewer. Changes made on the article text are indicated with red lines.
Response 1: - It has been revised in line with the recommendations of reviewer-3: “ In recent years, it has been reported that plant nutrient balance can be achieved with the use of as a biological fertilizer in mixture nitrogen fixers with phosphate solvents [25, 26] and soil pathogens can be better controlled [27].”
Response 3: The novelty of our study was already emphasized in the Introduction section in Line 86. “However, after the use of PGPRs as a biofertilizer in stock mother plant nutrition, no research was found in which the rooting performance of cuttings taken from these plants was examined.”
Response 4: Line 91 has been revised. “In this study, different bacterial formulations were used in the cultivation of poinsettia stock mother plants and it was aimed to evaluate the rooting status of cuttings taken from the stock mother plants.”
English language evaluation was was done in the entire article text.
Response 5: Line 102 – The Figure 1-d photo was changed.
Response 6: Line 118- Nitrogen and Phosphate in the Table 1 represents the nitrogen fixing and phosphorus solubilizing abilities determined as a result of some biochemical test results for bacterial strains isolated from the locations.
Also, descriptions of the concepts "Strong +, W: Weak +; +: Positive" are given below Table 1. “S: Strong +, strong nitrogen fixation property; W: Weak +, weak nitrogen fixation property; +: Positive”
“Based on the results of previous studies and some biochemical test results [32-35], bacterial strains found to have the best nitrogen fixation and phosphorus solubilizing properties were selected for use in the experiment.”
- The selected bacteria were isolated from the locations of the plants growing in their natural areas and positive results were obtained on many different plant species after isolation. It was asked to investigate whether these positive effects would be the same for poinsettia. More importantly, more important than the poinsettia used as a plant material, what could be the effects of PGPRs used in the cultivation of parent plants on propagation by cuttings?
Response 7: “In order to determine the best bacterial formulation, 3 PGPR strains with similar PGPR properties were selected.” Sentence was added in Line 143.
Information about the culture medium and growth conditions for bacterial strains is presented with reference (Turan et al. [37], Parlakova Karagöz et al. [38] and Kaymak et al. [39]).
Adding sugar is a routine practice for bacteria to adhere to the surface of seed or seedling root dipping. It does not make a difference between applications because the sterile culture medium + sugar is added to the control application.
Sentence was revised: “Each bacterial suspension (measured spectrophotometrically at 600 nm) was properly diluted to 1 × 108 CFU ⋅ mL−1 with distilled water.”
Response 8: Line 154 was added “Pots were sterilized with 20% sodium hypochlorite solution.”
Also, the growing medium and perlite were sterilized. These sentences have been added to the relevant places in the material and method section.
Response 9: The expression "in the cultivation of poinsettia stock mother plants" was used instead of the expression "plant nutrition".
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 4 Report
Article title:
“Impact of PGPR formulations combined with exogenous IBA levels to enhancing root capacity in poinsettia cuttings".
To increase root development and root yield of cuttings made from stock mother poinsettia plants, this study investigated the hypothesis that the use of bacterial mixtures made with PGPRs as biofertilizer in the cultivation of stock mother poinsettia plants and the determination of an effective IBA dose would be beneficial.
The work completed has unquestionably broad appeal, and the format used is unquestionably appropriate for an article. The topic was presented in a unique and appealing manner in this essay, and the titles are connected. The work is unique, particularly fascinating, and can undoubtedly inspire further study on the subject and the conclusion highlights the objectives of the study and its potential.
Regarding the manuscript, there are some points, which the authors should be to modify i.e.
- Line 26: NR (write complete).
- Line 30: NAS (write complete).
- Line 40, 83: rhizobacteria bacteria, delete bacteria
- Line 135: × 108 CFU, change to × 108 CFU
- Line 179: NaHCO3, change to NaHCO3
- Line 260 and 282: standart change to standard
- Line 266: 2000 mg l., change to 2000 mg l-1
- Line 463: formulation (Bacillus, delete (.
Author Response
Dear REviewer,
First of all, thank you very much for your ideas that highlight the importance of our work. Also, thank you for your careful and thoughtful evaluation. The whole article has been revised, especially the points you have mentioned.
Response 1: - Line 26: NR was writed as number of rooted cuttings (NR).
- Line 30: NAS was writed as number of mean shoots (NAS).
- The 'rhizobacteria bacteria' in the lines (40, 83) has been revised to rhizobacteria only.
- Line 135: × 108 CFU was changed to × 108 CFU
- Line 179: NaHCO3 was changed to NaHCO3
- Line 260 and 282: standart was changed to standard
- Line 266: 2000 mg l was changed to 2000 mg l-1
- Line 463: Bacteria information in parentheses has been deleted.
Round 2
Reviewer 2 Report
The authors have revised the manuscript according to the comments made on the first version of the manuscript, and I therefore suggest it could be published after a final check on the English language used.
Author Response
Dear Reviewer,
The text of the article has been edited. Changes made are marked in yellow. the article text document has been added.
Author Response File: Author Response.docx
Reviewer 3 Report
Although the authors responded to some of the questions, the main concerns about the paper quality remains: the main concept of the paper is still questionable, there are not enough experimental evidence to support the paper hypothesis, the experimental design concerning PGPR inoculation still has serious flaws, the discussions are still pure speculations when it comes to PGPR effect on mother plants nutrition.
Author Response
Dear Reviewer,
The text of the article has been edited. Changes made are marked in yellow. The changes you suggested have been made and these are highlighted in blue. The article text document has been added.
Thank you for your contribution.
Author Response File: Author Response.docx
