Differential Growth in Purslane Species Grown in Two Different Seasons

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors conducted a study on Differential growth in purslane species grown in two different seasons, which holds certain significance, but there are many issues.

 

18 What exactly do the “two agro-climatic conditions” refer to?

 

19 For the traits “with 3 replicates,” does this mean three plants per accession, or three independent blocks? Please clarify.

 

25–26 What is superior to P. oleracea species, higher yield, better morphological traits, or better nutritional value?

 

29–31 I do not recommend using the keywords “Portulaca umbraticola; Portulaca grandiflora; Portulaca halimoide; Portulaca werdermanni; Portulaca oleracea; Portulaca amilis.” The authors are not conducting a taxonomic study, and such keywords omit a great deal of relevant information. Moreover, the Latin name Portulaca halimoide seems incorrect; should it be Portulaca halimoides? And should Portulaca werdermanni actually be Portulaca werdermannii? Please confirm.

 

37–38 The sentence “We often do not explore the full food potential available in local biodiversity, being restricted to a small group of options.” is overly colloquial and contributes nothing to the article; it should be deleted.

 

43–49 I suggest using Latin names. There is substantial variation within the genus Portulaca—ornamental cultivars are mostly P. grandiflora, while edible types are mostly P. oleracea. Using “purslane” interchangeably could cause confusion.

 

The abstract is logically disorganized: it jumps from WEP/NCEP, to ornamental value of Portulaca, to nutritional value, then to phytoremediation and allelopathy. The themes shift abruptly, lacking a clear central thread. The authors should integrate and streamline the content to highlight the core focus of this study.

 

62–63 In fact, purslane is consumed as a wild vegetable in many regions or used as animal feed.

 

85–86 What exactly does “the aforementioned institution” refer to? How were these germplasms obtained? Since multiple species are involved, how did the authors verify the correct identification of seeds or cuttings? Relevant images should be provided.

 

87 Can results truly be represented by just three cuttings? Is this statistically appropriate?

 

89 The column header should be “Accession,” not “Acession.”

 

95–97 Was the greenhouse environmentally controlled (temperature, humidity, light)? If both summer and winter trials were conducted in a greenhouse, how can a genuine “seasonal effect” be ensured?

 

108 If the authors propagated plants via cuttings, why is “sowing” mentioned? And what was the rationale for choosing 45 days? Only one measurement was taken? What about growth dynamics?

 

118 Why was (p≤0.01) chosen rather than the more common 0.05? Why did the authors use the Scott–Knott test instead of more commonly used multiple comparison methods like Tukey’s?

 

Given the number of varieties, why didn’t the authors include images for visualization? The tables are nearly unreadable.

 

Table 3 lacks crucial statistical information, df, F values, and error terms are missing, and no CV (coefficient of variation) is provided. Listing only Mean Squares without statistical test references makes it impossible for readers to verify the reported significance.

 

Table 4 needs a clear footnote explaining whether uppercase and lowercase letters indicate row-wise or column-wise comparisons. Standard deviation (SD) or standard error (SE) is also missing.

 

Table 5 similarly lacks SD/SE, and numerical precision is inconsistent.

 

220 Where did the authors measure “yield”? Fresh weight, dry weight, yield per area? The text mentions “yield differences” without supporting data. Is this the authors’ conclusion or is it cited from literature?

 

In the discussion, it is often unclear which statements are “experimental findings” and which are “refs comparisons.”

 

226–229 The narrative abruptly shifts, from emphasizing P. oleracea as an edible species, to “ornamental purposes,” then to “vegetable production”, with no transition.

 

236–237 The sentence “The majority of scientific works about purslane did not evaluate this trait [11, 23, 26, 27, 25, 28, 29, 30,31, 32].” contains excessive citations.

 

239 (Souza et al. 2024) is not formatted according to journal style.

 

The conclusion has many issues: multiple typos such as writing P. olearacea instead of P. oleracea; the sentence “It is important highlighted it is important…” is grammatically incorrect, repetitive, and must be rewritten. The sentence structure is poor, and the tone is overly colloquial.

 

243–261 In the plant height and stem diameter sections, the authors directly compare their data to numbers from other studies without accounting for key variables (sampling time, growth stage, cultivation method, measurement method). For example, was measurement taken 45 days after sowing/cutting in this study? Were cited studies measured at the same stage? Some references used field cultivation, others soilless substrates, these environmental differences make direct numerical comparisons invalid.

 

Section 4.3 contains virtually no meaningful content.

Author Response

First of all, thank you very much for taking the time to review this manuscript. We think the reviewer’s comments improved the manuscript quality. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

Reviewer 1

Comment 1:

18 What exactly do the “two agro-climatic conditions” refer to?

Response 1:

The term two “agro-climatic conditions” refer to two seasons. Therefore, this term was replaced this sentence by two seasons, please, see in the manuscript (line 17 and 18).

Comment 2:

19 For the traits “with 3 replicates,” does this mean three plants per accession, or three independent blocks? Please clarify.

Response 2:

It was used three plants per accession. This information was added in the manuscript (line 19).

Comment 3:

25–26 What is superior to P. oleracea species, higher yield, better morphological traits, or better nutritional value?

Response 3:

Better morphological traits. We added this information in the manuscript (line .26).

Comment: 4

29–31 I do not recommend using the keywords “Portulaca umbraticola; Portulaca grandiflora; Portulaca halimoide; Portulaca werdermanni; Portulaca oleracea; Portulaca amilis.” The authors are not conducting a taxonomic study, and such keywords omit a great deal of relevant information. Moreover, the Latin name Portulaca halimoide seems incorrect; should it be Portulaca halimoides? And should Portulaca werdermanni actually be Portulaca werdermannii? Please confirm.

Response 4:

We agree with this comment. Therefore, we modified the keywords, please, see in the manuscript (line 30).

Comment 5:

37–38 The sentence “We often do not explore the full food potential available in local biodiversity, being restricted to a small group of options.” is overly colloquial and contributes nothing to the article; it should be deleted.

Response 5:

We agree with this comment. Therefore, the sentence was deleted.

Comment 6:

43–49 I suggest using Latin names. There is substantial variation within the genus Portulaca—ornamental cultivars are mostly P. grandiflora, while edible types are mostly P. oleracea. Using “purslane” interchangeably could cause confusion.

Response 6:

We agree with this comment. Therefore, the sentence was modified, please, see the manuscript (lines 43 and 44).

Comment 7:

The abstract is logically disorganized: it jumps from WEP/NCEP, to ornamental value of Portulaca, to nutritional value, then to phytoremediation and allelopathy. The themes shift abruptly, lacking a clear central thread. The authors should integrate and streamline the content to highlight the core focus of this study.

Response 7:

Sorry, but I did not understand what the reviewer want in this comment. Please, see above in the comment the reviewer start speaking about the abstract. I really read the abstract and there is no such information in there.

Comment 8:

62–63 In fact, purslane is consumed as a wild vegetable in many regions or used as animal feed.

Response 8:

We agree with this comment. Therefore, we added this information in the manuscript (Lines 45 and 46).

Comment 9:

85–86 What exactly does “the aforementioned institution” refer to? How were these germplasms obtained? Since multiple species are involved, how did the authors verify the correct identification of seeds or cuttings? Relevant images should be provided.

Response 9:

We agree with this comment. Therefore, we added the name of the university and also a figure with the species and accessions used in the study (lines 89 to 91).

A PhD in Botany Doctor Thaíla Vieira A. Santos made the identifications. In the Acknowledgements we cited her.

Photography of the analyzed species was added in supplementary Material.. Please, see Figure 1, 2 and 3 in the manuscript ( attached file).

Comment 10:

87 Can results truly be represented by just three cuttings? Is this statistically appropriate?

Response 10:

I hope the comments below helps to clarify the reviewer questions.

Our experiment was based on a previous work published by Alam et al. 2014 [1], please see the reference below. Therefore, we added this information in the manuscript. Beside this, considering that the experiment was duplicated in time we believe it is representative of the accessions bulk.

Furthermore, using the p-value of 0.01 reduces the probability of rejecting H0 if it is true (Type I error) since we use three cuttings as replicates as you can see in Zar [2], 1999 (Page 178).

1) Alam, M. A., Juraimi, A. S., Rafii, M. Y., Hamid, A. A., Aslani, F., & Mohsin, G. M. (2014). A Comparison of Yield Potential and Cultivar Performance of 20 Collected Purslane (Portulaca oleracea L.) Accessions Employing Seeds vs. Stem Cuttings. Journal of Agricultural Science and Technology, 16(7), 1633-1648.

2) Zar, J. H. Biostatistical analysis. Pearson Education India, 1999.

 

Comment 11:

89 The column header should be “Accession,” not “Acession.”

Response 11:

We agree with this comment. Therefore, we made the change in the manuscript (page 94).

Comment 12:

95–97 Was the greenhouse environmentally controlled (temperature, humidity, light)? If both summer and winter trials were conducted in a greenhouse, how can a genuine “seasonal effect” be ensured?

Response 12:

The greenhouse had not environmental control, then we believe in the insurance of seasonal effect estimative.

Comment 13:

108 If the authors propagated plants via cuttings, why is “sowing” mentioned? And what was the rationale for choosing 45 days? Only one measurement was taken? What about growth dynamics?

Response 13:

We agree with this comment. Therefore, we replace the term sowing by propagation (line 117).

In the majority of literature with Portulaca the data collection is at the flowering stage wihich is around 45 days. It was also based based on previously published literature (page 188). The authors state that purslane is ready to be harvested between six and eight weeks. Please see the reference below [1]. We also based on our experience from previous works. In our region's climate, purslane can be harvested from 40 to 83 days after propagation, please see the references below [2,3]. Since the experiment was replicated in time we decided not to follow the growth.

• https://hort.extension.wisc.edu/articles/common-purslane-portulaca-oleracea/

 

• Pessoa, A. M. D. S., Freitas, S. Q. D., Lima, F. F. D., Santos, F. J., Aquino, G. S. D., Sousa, W. K. D., ... & Rêgo, E. R. D. (2025). Parental selection in Portulaca umbraticola Kunth for ornamental purposes. Revista Brasileira de Engenharia Agrícola e Ambiental, 29(10), e291158.

 

• Souza, J. D. S., Rêgo, E. R. D., Freitas, N. D. S. S., Pessoa, A. M. D. S., Silva, P. D., & Rêgo, M. M. D. (2024). Phenotypical characterization of Portulaca umbraticola: A non-conventional edible ornamental crop. Acta Scientiarum. Agronomy, 46, e62326.

Comment 14:

118 Why was (p≤0.01) chosen rather than the more common 0.05? Why did the authors use the Scott–Knott test instead of more commonly used multiple comparison methods like Tukey’s? Given the number of varieties, why didn’t the authors include images for visualization? The tables are nearly unreadable.

Response 14:

Question 1. Using the p-value of 0.01 reduces the probability of rejecting H0 if it is true (Type I error) since we use three cuttings as replicates [1].

Question 2. to be separated into exclusive groups without overlapping as occurs in the Tukey’s test, and for this reason, it was chosen [2; 3]. Beside this, Scott-Knott’s test is viable alternative to supply the need of an experiment with low number of replicates and large number of genotypes [2].

• ZAR, J. H. Biostatistical analysis. Pearson Education India, 1999, pages 231-250 and pages 178.
• SCOTT, A. J., & KNOTT, M. (1974). A cluster analysis method for grouping means in the analysis of variance. Biometrics, 507-512.

 

• MALAQUIAS, J.V.; AMABILE, R.F.; ZORZO, F.; MELO, J.V.P.; FAGIOLI, M. Analysis of variance in augmented block design and Scott- Knott’s test in hybrid corn selection studies. Pesquisa Agropecuária Brasileira, v.58, e03023, 2023. DOI: https://doi.org/10.1590/ S1678-3921.pab2022.v57.03023.

Question 3. We chose to present the data in tables due to the large number of variables. In our opinion, the table allows for the visualization of all the data in a single view.

Comment 15:

Table 3 lacks crucial statistical information, df, F values, and error terms are missing, and no CV (coefficient of variation) is provided. Listing only Mean Squares without statistical test references makes it impossible for readers to verify the reported significance.

Table 4 needs a clear footnote explaining whether uppercase and lowercase letters indicate row-wise or column-wise comparisons. Standard deviation (SD) or standard error (SE) is also missing.

Table 5 similarly lacks SD/SE, and numerical precision is inconsistent.

Response 15:

We agree with this comment. Therefore, we added this information (DF, Error and CV) in the Table 3, Table 4 and Table .The standard error and footnotes with the mean of the letters was also added in Table 4 (from line 141`to line 214)..

Comment 16:

220 Where did the authors measure “yield”? Fresh weight, dry weight, yield per area? The text mentions “yield differences” without supporting data. Is this the authors’ conclusion or is it cited from literature?

In the discussion, it is often unclear which statements are “experimental findings” and which are “refs comparisons.”

 Response 16:

We agree with this comment. Therefore, we made modifications in this section. We hope helps to clarify about these questions (line 222).

In the experimental findings we cited the appropriated table where they are found in the results section.

Comment 17:

226–229 The narrative abruptly shifts, from emphasizing P. oleracea as an edible species, to “ornamental purposes,” then to “vegetable production”, with no transition.

Response 17:

We agree with this comment. Therefore, we modified this sentence (lines 230 to 234).

Comment 18:

236–237 The sentence “The majority of scientific works about purslane did not evaluate this trait [11, 23, 26, 27, 25, 28, 29, 30,31, 32].” contains excessive citations.

Response 18:

. Sorry, but we do not agree with this point. How can we start with the statement “the majority of scientific works” and do not made the references about them?

Comment 19:

239 (Souza et al. 2024) is not formatted according to journal style.

Response 19:

We agree with this comment. Therefore, the reference was modified (lines 361 and 362). We hope it is ok now.

Comment 20:

The conclusion has many issues: multiple typos such as writing P. olearacea instead of P. oleracea; the sentence “It is important highlighted it is important…” is grammatically incorrect, repetitive, and must be rewritten. The sentence structure is poor, and the tone is overly colloquial.

Response 20:

We agree with this comment. Therefore, the conclusion was rewritten (from line 298 to 306).

Comment 21:

243–261 In the plant height and stem diameter sections, the authors directly compare their data to numbers from other studies without accounting for key variables (sampling time, growth stage, cultivation method, measurement method). For example, was measurement taken 45 days after sowing/cutting in this study? Were cited studies measured at the same stage? Some references used field cultivation, others soilless substrates, these environmental differences make direct numerical comparisons invalid.

Response 21:

We only compare with trials where the data were collected before flowering as our work.

Comment 22:

Section 4.3 contains virtually no meaningful content.

Response 22:

We agree with this comment. Therefore, we rewrite this section (lines .291 to 296)

 

Reviewer 2 Report

Comments and Suggestions for Authors

In this manuscript, the author studied and evaluated the morphological differences of 18 purslane germplasms in winter and summer, aiming to screen out germplasms with stable traits and excellent agronomic characteristics for future breeding. The topic is in line with the global demand for food security and climate-adaptive crops, and the experimental design is basically reasonable.Although the topic is pertinent to the breeding of resilient non-conventional edible plants, the work exhibits major deficiencies in experimental conditions, methodology, and analytical depth, and consequently fails to provide novel insights into purslane breeding or agronomy. The principal concerns are outlined below.

 

1. The introduction briefly mentions the potential of purslane as a non-traditional edible plant, yet fails to comprehensively integrate existing literature to elucidate its core advantages as an "alternative crop" and the current research gaps in this domain.

 

2. In materials and methods the authors state that the experiment was laid out with three replicates in a 2-season × 18-accession factorial design. The manuscript, however, reports growth data for only one summer cycle (17 Oct 2022–23 Jan 2023) and one winter cycle (1 May 2023–7 Aug 2023). At minimum, data from three consecutive years for both summer and winter seasons should have been collected; the experimental design is therefore insufficiently rigorous.

 

3. The data on temperature, humidity, etc. in Table 2 are split by month and do not directly compare the overall differences between the two seasons. For instance, the average temperature in summer is 22.6 - 23.5℃ versus 21.0 - 22.8℃ in winter, making it difficult to intuitively understand the impact of the seasons on plants.

 

4. The authors merely documented basic growth parameters (canopy width, plant height, stem diameter, internode distance, leaf width, leaf length, flower diameter, number of leaves, and number of branches) for the 18 accessions in summer and winter. No further investigation—such as gene expression, protein function, or biochemical characterization—was undertaken, rendering the experimental design overly simplistic.

 

5. The authors assert that superior accessions (PU02, PU10, PU11, etc.) should be used for hybridization programs, but no evidence is provided for heritability, heterosis, or trait correlations.

 

6. While the Introduction emphasizes *Portulaca*’s nutritional value (ω-3 fatty acids, vitamins), no data are presented on phytochemical profiles or edibility of the evaluated accessions.

 

7. The proportion of references from the past five years is less than 30%. For instance, the genomic research on Portulaca after 2020 has not been cited. It is recommended to update the references.

 

8. Some terms are inconsistent, such as the mixed use of "purslane species" and "Portulaca spp.", which should be uniformly expressed in Latin scientific names.

Author Response

First of all, thank you very much for taking the time to review this manuscript. We think the reviewer’s comments improved the manuscript quality. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

 

Reviewer 2

Comment 1

The introduction briefly mentions the potential of purslane as a non-traditional edible plant, yet fails to comprehensively integrate existing literature to elucidate its core advantages as an "alternative crop" and the current research gaps in this domain.

 Response 1

We agree with this comment. Therefore, the Introduction was rewritten (pages 43 to 53).

Comment 2

In materials and methods the authors state that the experiment was laid out with three replicates in a 2-season × 18-accession factorial design. The manuscript, however, reports growth data for only one summer cycle (17 Oct 2022–23 Jan 2023) and one winter cycle (1 May 2023–7 Aug 2023). At minimum, data from three consecutive years for both summer and winter seasons should have been collected; the experimental design is therefore insufficiently rigorous.

 Response 2

Sorry but we disagree with this statement. When you perform a two-factor analysis of variance you do not need make repetitions in time. We perform a two-factor analysis of variance with equal replication.

A two-way ANOVA statistical model for genotype and seasons is typically expressed as: Yijk = µ + Gi + Sj + (GS)ij + εijk, where Yijk is the phenotypic response for the i-th genotype (Gi) in the j-th season (Sj), µ is the general mean, (GS)ij is the genotype by season interaction term, and εijk is the random error. This model accounts for the effects of genotype and season independently, as well as their combined interaction effect on the trait being measured.

On the other hand if you add replicates in time, we should performance another statistical analysis considering the variation within season. This result in a three-way analysis of variance with the following model:

yijkl = µ + τi + βj + γk + (τβ)ij + (τγ)ik + (βγ)jk + (τβγ)ijk + eijkl 

• yijkl: The observed outcome for the l-th observation in the ith level of factor A, jth level of factor B, and kth level of factor C.

• µ: The baseline mean.
• τi, βj, γk: Main factor effects.
• (τβ)ij, (τγ)ik, (βγ)jk: Two-way interaction effects.
• (τβγ)ijk: The three-way interaction effect.
• eijkl: The random error term.

For more details about these analysis , please, see the following reference or any other book of Statistical analysis.

Zar, J. H. Biostatistical analysis. Pearson Education India, 1999, pages 231-250 and pages 282-299.

Comment 3

The data on temperature, humidity, etc. in Table 2 are split by month and do not directly compare the overall differences between the two seasons. For instance, the average temperature in summer is 22.6 - 23.5℃ versus 21.0 - 22.8℃ in winter, making it difficult to intuitively understand the impact of the seasons on plants.

 Response 3

Sorry, but we disagree with this statement. Meteorological data were collected throughout the months of evaluation because we assumed that the plant's development was affected by these variations. Using only averages would lose this effect, and we may be underestimating the impact of meteorological variables on plant growth.

Comment 4

The authors merely documented basic growth parameters (canopy width, plant height, stem diameter, internode distance, leaf width, leaf length, flower diameter, number of leaves, and number of branches) for the 18 accessions in summer and winter. No further investigation—such as gene expression, protein function, or biochemical characterization—was undertaken, rendering the experimental design overly simplistic.

Response 4

Sorry, but we disagree with this statement. This work was made based on quantitative data, which is a part of quantitative genetics. We do not work with molecular data. Our research group works with quantitative genetics, applied statistics, and biometrical models applied to plant breeding.

The goal of our work was to fill the gap of agronomical information about production since there is a gap in the literature about agronomical trials.

With all respect of the comments, we can not expect that all scientific work have to applied molecular data, genomics or proteomic. Regarding the biochemical characterization it was not our goal in this work. We emphasized that on Introduction section only to highlight the importance of consuming Portulaca species since they are a nutraceutical vegetable.

Comment 5

The authors assert that superior accessions (PU02, PU10, PU11, etc.) should be used for hybridization programs, but no evidence is provided for heritability, heterosis, or trait correlations.

 Response 5

We agree in part with this statement. Therefore, we added the estimates of heritability in the tex (lines 138 and 139). On the other hand, we cannot provide heterosis estimates because we did not work with hybrids.

The goal of our work was estimate the differential behavior for the analyzed accessions in different environmental condition in order to select the more stables to proceed the hybridization.

Comment 6

While the Introduction emphasizes *Portulaca*’s nutritional value (ω-3 fatty acids, vitamins), no data are presented on phytochemical profiles or edibility of the evaluated accessions.

Response 6

We agree with this comment. Therefore we modify the Introduction in hope to clarify our goal (pages 43 to 53).

Please, see the response of comment 4, where we explain that.

Comment 7

The proportion of references from the past five years is less than 30%. For instance, the genomic research on Portulaca after 2020 has not been cited. It is recommended to update the references.

 Response 7

Sorry, but we disagree with this statement.

In the instruction for authors in the reference topic, there is any statement guiding us to use only references from the past five years. On the other hand, we cannot to cite genomic research since our work is not about genomics. Please see the response of comment 4.

Comment 8

Some terms are inconsistent, such as the mixed use of "purslane species" and "Portulaca spp.", which should be uniformly expressed in Latin scientific names.

Response 8

We agree with this statement. Therefore we made the asked changes (lines 218-224).

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed most of my questions, and I have no major concerns regarding the manuscript. Just a few minor issues: the authors do not seem to have uploaded the supplementary materials. If the figures are included in the supplementary file, then line 91“Figure 1 xx” should be corrected to Figure S1, Figure S2, and Figure S3. In addition, some Latin names in the text should be italicized, such as P. umbraticola (line 303), P. oleracea (line 311), and P. umbraticola (line 323), and others.

Author Response

First of all, thank you very much for taking the time to review this manuscript. We think the reviewer’s comments improved the manuscript quality. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

Reviewer 1

Comment 1:

The authors have addressed most of my questions, and I have no major concerns regarding the manuscript. Just a few minor issues: the authors do not seem to have uploaded the supplementary materials. If the figures are included in the supplementary file, then line 91“Figure 1 xx” should be corrected to Figure S1, Figure S2, and Figure S3. In addition, some Latin names in the text should be italicized, such as P. umbraticola (line 303), P. oleracea (line 311), and P. umbraticola (line 323), and others.

 

Response 1:

We uploaded the supplementary materials and made the changes in the line 91“Figure 1 xx” should be corrected to Figure S1, Figure S2, and Figure S3.

 

The Latin names were italicized, such as P. umbraticola (line 303), P. oleracea (line 311), and P. umbraticola (line 323), and others.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The author has responded to my suggestions and made revisions accordingly. After carefully reviewing them, I agree with all the modifications and responses. 

The authors have included three subheadings in the discussion section, but I recommend removing them. The third subheading, in particular, contains very little substantive content. Additionally, these subheadings appear more appropriate for the results section rather than the discussion.

Author Response

Reviewer 2

Comment 1

The author has responded to my suggestions and made revisions accordingly. After carefully reviewing them, I agree with all the modifications and responses. 

The authors have included three subheadings in the discussion section, but I recommend removing them. The third subheading, in particular, contains very little substantive content. Additionally, these subheadings appear more appropriate for the results section rather than the discussion.

 

Response 1

The subheadings in the discussion section were removed.

 

Author Response File: Author Response.pdf