Taxonomy, Phylogeny, and Life Cycle of Four Neophysopella Species on Meliosma myriantha and M. oldhamii in Korea
Round 1
Reviewer 1 Report
This paper clarified morphological and phylogenetic differences of 4 species of Neophysopella on plant species of Meliosma based on specimens collected in Korea. Life cycles of these species were also clarified by field observations and phylogenetic analyses. Therefore, this paper is acceptable for publication. However, following points should be reconsidered before publication.
Line 4: Hyen-Dong Sin 2 ?
Line 16: Two species are autoecious. Do these species need alternate host plants?
Line 18: each macrocyclic stage. What is this meaning?
Line 33: their significant ecological roles. Need to explain their roles how they maintain biodiversity and forest health.
Line 36: Cited reference 10. But this reference reported Phakopsora, not Neophysopella. Need to add references describing Neophysopella.
Line 47: Same as above.
Line 67: Table 1. Need to arrange style. Spore stages on specimens are important information for this study. Need to add this information to table.
Line 69: Histological. “Histopathological” is better.
Line 98: Life cycle and alternate host. “Field observation” is better.
Line 149-158: Is there possibility of infections mixed together with two or three species? Need to discuss mixed-infection of two or three species on the same host plant.
Line159-160: Need to discuss distribution of 4 species. Are they observed in the same place or different place? Is there any relationship between distribution of Meliosma species and occurrence of Neophysopella species?
Line 184: Need to add distribution of each species in Korea
Line 307: Figure 7. Host plant of F, G and H is not Meliosma.
Line 312: Figure 8. Host plant is not only Meliosma.
Line 346, 351: Figure 9, 10. Host plant is not only Meliosma.
Line 381: Figure 11. Morphology of teliospores is those of Puccinia (?), not Neophysopella. Need to change.
Line 383: other alternate host plant? N. meliosmae has no alternate host plant.
Author Response
Reviewer 1
This paper clarified morphological and phylogenetic differences of 4 species of Neophysopella on plant species of Meliosma based on specimens collected in Korea. Life cycles of these species were also clarified by field observations and phylogenetic analyses. Therefore, this paper is acceptable for publication. However, following points should be reconsidered before publication.
Line 4: Hyen-Dong Shin 2 ?
→ corrected
Line 16: Two species are autoecious. Do these species need alternate host plants?
→ specified two heteroecious species.
Line 18: each macrocyclic stage. What is this meaning?
→ revised "at each stage of their life cycles"
Line 33: their significant ecological roles. Need to explain their roles how they maintain biodiversity and forest health.
→ This sentence was revised to emphasize the trees' present-day benefits rather than their unspecified roles.
Line 36 & 47: Cited reference 10. But this reference reported Phakopsora, not Neophysopella. Need to add references describing Neophysopella.
→ Added the reference.
Line 67: Table 1. Need to arrange style. Spore stages on specimens are important information for this study. Need to add this information to table.
→ Added the spore stage for all specimens in Table 1.
Line 69: Histological. "Histopathological" is better.
→ revised
Line 98: Life cycle and alternate host. "Field observation" is better.
→ revised
Line 149-158: Is there a possibility of infections mixed together with two or three species? Need to discuss mixed-infection of two or three species on the same host plant.
→ Thanks for this sense comment. The authors added a discussion for the mixed infection: While we found several M. myriantha leaves exhibiting symptoms of two or three rust species, such samples were excluded from the current study to prevent misidentification arising from the mixed infection. Further research is needed to verify whether these rust species co-infect a single plant.
Line159-160: Need to discuss distribution of 4 species. Are they observed in the same place or different place? Is there any relationship between distribution of Meliosma species and occurrence of Neophysopella species?
→ added: "The two host plants (Meliosma myriantha and M. oldhamii) are widely distributed in the southwestern areas of Korea. However, our field observations indicated that N. hornotina is confined to a specific region (Wanju-gun) of Jeollabuk-do, whereas the distribution of N. vitis broadly aligns with one of M. myriantha." In addition, the authors added the geographic distribution of each species in the Taxonomy.
Line 184: Need to add distribution of each species in Korea
→ added the geographic distribution of each species.
Line 307: Figure 7. Host plant of F, G and H is not Meliosma.
→ added the host plant name for F, G and H
Line 312: Figure 8. Host plant is not only Meliosma.
→ added its host plant name.
Line 346, 351: Figure 9, 10. Host plant is not only Meliosma.
→ added the host plant name for Figures 9 and 10
Line 381: Figure 11. Morphology of teliospores is those of Puccinia (?), not Neophysopella. Need to change.
→ changed the picture with teliospores of Neophysopella
Line 383: other alternate host plant? N. meliosmae has no alternate host plant.
→ deleted "other alternate host plant"
Reviewer 2 Report
‘Taxonomy, Phylogeny, and Life Cycle of Four Neophysopella species on Meliosma myriantha and M. oldhamii in Korea’
The authors have undertaken a comprehensive study on 73 field collected samples of infected leaves in Korea to understand the life-cycle, morphology and evolutionary relatedness of pathogens that cause rust disease on two species of Meliosma. Of particular interest is the clarification of the alternate host for two of the four rust-causing pathogens.
General comments:
I found the study to be sound and the data reasonably well presented, however I have a few comments and edits that I think will improve the manuscript for publication.
1. The authors often refer to rust species or rust pathogen. Rust is the disease symptom caused by the microbe or fungal pathogen. This should be corrected throughout the manuscript or alternatively, make the case for referring to the causal agent to be termed rust (within this manuscript) or cite an example of this use in other research paper.
2. I think that the hypothesis being tested could be clearly stated in the introduction. What is the key question that the researchers are asking? In this case it seems that the authors had a goal to clarify the taxonomy and life-cycle for this pathogen?
3. While no alternate host was identified in this study, perhaps this study is not conclusive that N. hornotina and N. myrianthae are autoecious?
4. Please also see intext edits in the attached manuscript.
Methods:
2.1 Sample collections.
It appears that collections were made opportunistically rather than systematically. While I appreciate that this is often necessary for disease causing agents, the collection method should be stated clearly. Was there a random sampling approach/grid/GPS locations? It would be useful to present the locations on a map.
2.2 Histology.
Please describe how the four Neophysopella species were designated to guide the histological examination of each life-cycle stage. Were these examinations completed after the phylogeny studies or based on the host species or cross-referenced later?
Comments for author File: 
Comments.pdf
Author Response
General comments:
- The authors often refer to rust species or rust pathogen. Rust is the disease symptom caused by the microbe or fungal pathogen. This should be corrected throughout the manuscript or alternatively, make the case for referring to the causal agent to be termed rust (within this manuscript) or cite an example of this use in other research papers.
Answer: Thank you for your insightful comment. While it's true that disease names are not interchangeable with their causative pathogens, there are exceptions. In instances where a group of fungi is solely responsible for a specific disease—like Pucciniales causing rust disease, Erysiphales causing powdery mildew, and Peronosporales causing downy mildew—the name of the disease is widely used also to identify the pathogen responsible. For example, a Google Scholar search reveals that the terms "rust species" and "rust pathogen" have appeared in over 15,000 scientific papers (see references below).
- LUO, Ming, et al. A five-transgene cassette confers broad-spectrum resistance to a fungal rust pathogen in wheat. Nature Biotechnology, 2021, 39.5: 561-566.
- LI, Feng, et al. Emergence of the Ug99 lineage of the wheat stem rust pathogen through somatic hybridization. Nature communications, 2019, 10.1: 5068.
- AWAIS, Muhammad, et al. Himalayan mountains imposing a barrier on gene flow of wheat yellow rust pathogen in the bordering regions of Pakistan and China. Fungal Genetics and Biology, 2023, 164: 103753.
- I think that the hypothesis being tested could be clearly stated in the introduction. What is the key question that the researchers are asking? In this case it seems that the authors had a goal to clarify the taxonomy and life-cycle for this pathogen?
Answer: In the last paragraph of the Introduction, the authors clarified the aim of the present research.
- While no alternate host was identified in this study, perhaps this study is not conclusive that N. hornotina and N. myrianthae are autoecious?
Answer: the authors found that N. hornotina and N. meliosmae developed all different stages on each host plant. It means that neither species requires an additional host to complete its life cycle. Similar observations about their autoecious life cycles have been documented in Japan.
- Please also see intext edits in the attached manuscript.
Answer: Thank you for your valuable contributions to our manuscript. We have incorporated all of your suggested edits in the revised text.
- Methods:
2.1 Sample collections: It appears that collections were made opportunistically rather than systematically. While I appreciate that this is often necessary for disease causing agents, the collection method should be stated clearly. Was there a random sampling approach/grid/GPS locations? It would be useful to present the locations on a map.
Answer: the authors systematically investigated the rust occurrence on the host plants using the occurrence data for the two plants. This method was added as “We sourced the occurrence data for the two plants in Korea from the Global Biodiversity Information Facility (GBIF.org (31 August 2023) GBIF Occurrence Download https://doi.org/10.15468/dl.43h4bn for M. myriantha; GBIF.org (31 August 2023) GBIF Occurrence Download https://doi.org/10.15468/dl.uygkfb for M. oldhamii)”.
The authors are still investigating the locations where these pathogens occur and preparing for an ecological study on them. Since the present research focuses on the classification, phylogeny, and life history of rust fungi, we would like not to use a map. Instead, we've summarized information on the geographic distribution of each species in the taxonomy section.
2.2 Histology: Please describe how the four Neophysopella species were designated to guide the histological examination of each life-cycle stage. Were these examinations completed after the phylogeny studies or based on the host species or cross-referenced later?
Answer: Histological analysis was performed after the species identification by phylogenetic analysis.
