Variations in the Growth of Cotyledons and Initial True Leaves as Affected by Photosynthetic Photon Flux Density at Individual Seedlings and Nutrients

Round 1

Reviewer 1 Report

General comments-

Hayashi et al developed a modular seedling production system (MSPS) for precise and non-destructive phenotyping. They validated the system by testing romaine lettuce seedlings from cotyledon unfolding to appearance of first true leaf stage under nutrient and water only conditions. Analysing RGB image data taken in an interval of 0.5 h, they calculated various plant growth related parameters, and noted a remarkable difference in the performance of seedlings under presence and absence of nutrients. The manuscript represents the important developments in the research area of high-throughput phenotyping. The adopted methodology, considered parameters, and interpretation and presentation of the results are very soundful and nicely done. Authors have also reflected the limitation of current study with probable approaches to overcome such challenges which will be helpful for researchers currently working in this field.

Below are my comments: 

Comment 1: Abstract is lacking the future implications of key findings of current study.

Comment 2: Authors need to mention about the number of individual plants placed in a single tray in the respective method section.

Author Response

Thank you very much for taking the time to review our work promptly. We appreciate your instructive suggestions. We are grateful for the opportunity to improve our manuscript. Thank you.

Point 1: Abstract is lacking the future implications of key findings of current study.

Response 1: We appreciate the reviewer’s point and suggestion. We have rewritten the abstract by adding the future implications of key findings of the current study. The number of total words in the abstract has been adjusted by minor amendments in some sentences. (L15; L20–22; L28–30).

Point 2: Authors need to mention about the number of individual plants placed in a single tray in the respective method section.

Response 2: Thank you for the suggestion. We have added the number of individual plants for each treatment and a single tray with additional explanations in the method section (L164–166; L169).

Reviewer 2 Report

The working methods used are appropriate to the proposed objective, so special devices have been created for the development of plant seedlings, in which humidity and temperature are constant, microenvironments that mimic natural environments ennobled with different types of organic nutrients. It is well known that variations in plant development and plant mass generation are dependent on soil and climatic conditions. Monitoring them by creating stable microenvironments is to the advantage of the development of certain types of plant species, with the generation of higher productive mass and higher quality. Assisted growth in artificial environments allows the production of organic crops, pesticide and heavy metal residues from different types of fertilizers are thus avoided. The use of artificial light technologies will certainly become a methodology applicable to different types of vegetable crops.

The diagrams used in expressing the results are justifying, highlighting the optimal evolutionary time of the cotyledon and the period in which the new seedlings develop. The observations made by the authors at different time intervals are relevant for the purpose of the research, the results obtained can be translated into the mass culture of different medicinal and non-medicinal species.

In conclusion, a very complex research, very well described the methodologies of analysis, processing of results and their correlation with the data reported in the literature.

Author Response

Thank you very much for taking the time to review our work. We appreciate your prompt review and thoughtful and insightful comments.