Review Reports - Bulgarian Local Cherry Genetic Resources towards Sustainable Agriculture

Round 1

Reviewer 1 Report

Research on pathogen resistance, local cherry cultivars is very interesting. Gene resources of local varieties can be a source of genes for resistance breeding. I have some questions about local cultivars.

1.Do the local cultivarsincluded in the study have high dessert value?

2. For what reason were they included in the study?

3.Please clearly indicate the research hypothesis in the manuscript

4. Conclusions are very laconic, please indicate clearly how the results answer the authors' hypotheses

Author Response

Dear reviewer, thank you for your comments of the article.

Point 1. Do the local cultivars included in the study have high dessert value?

Response 1: The fruits of SM-57 (found at 43°00'06.0"N 24°55'31.9"E) have a primitive taste qualities, but it was widely spread as single trees in old vineyards in some small mountain villages because of its ripening period, yields and appearance. In present days, it exists only as very old single trees in abandoned places, thriving despite the lack of cares.

Specimen SM-58 (found at 43°00'08.5"N 24°55'26.1"E) has very good taste, but it lacks the adequate fruit size for the modern-day market. Because of its resistance to brown rot, it is recommended to be included in crossings with large-fruited cultivars in order to achieve the breeding goals of FGI-Plovdiv’s breeding programme.

Point 2. For what reason were they included in the study?

Response 2: As mentioned in the “3.1. Plant sampling and field observations” section of the article, during scientific expeditions, several local cherry forms were discovered without visual symptoms of brown rot and cherry leaf spot. We selected the two most promising specimens combining resistance to both pathogens. During the lab tests, only the resistance to brown rot of SM-58 was confirmed.

Point 3. Please clearly indicate the research hypothesis in the manuscript

Response 3: We have improved the “Introduction” section as follows:

During these scientific expeditions, several local cherry forms were discovered without visual symptoms of brown rot and cherry leaf spot. The objectives set in this paper are to confirm the degree of field resistance / low susceptibility of the specimens by conducting laboratory tests with artificial inoculations of fruits and leaves. The results would contribute to both the conservation of local genetic resources and enhancement of the sweet cherry breeding programme in the Fruit Growing Institute – Plovdiv, Bulgaria (FGI).

Point 4. Conclusions are very laconic, please indicate clearly how the results answer the authors' hypotheses

Response 4: We have improved the “Conclusions” section as follows:

The cherry specimen SM-58 is immune when inoculated with the test pathogen Monilinia laxa (Aderh. and Ruhl.) Honey from the phytopathological collection of FGI-Plovdiv and therefore is recommended as a donor of resistance in the sweet cherry breeding programme in the institute.

Reviewer 2 Report

The work deals with the important topic of adapting fruit crops to climate change and the growing pressure of diseases and pests. The uniform nursery material of similar varieties, used in large areas, contributes to increasing the problems in cultivation. The most important and most sensible way to deal with these problems is to look for plants with high genetic resistance to diseases and adapted to local climatic conditions. Especially wild plants that produce healthy and tasty fruit can become the beginning of a new breeding of varieties. This action affects many plant species.

The results of the research indicate a promising application in the future of the obtained specimens, which may significantly contribute to the improvement of the stability of fruit production. The proposed research may be an example for other regions where similar research is also carried out (e.g. in Poland, where old apple trees are searched for).

A particularly valuable element of the work is the indication of the resistance and degree of infection after pathogen inoculation, which clearly indicate the suitability of selected specimens for further work.

the research results are very promising and research should be continued.

Author Response

Point 1: The research results are very promising and research should be continued.

Response 1: Dear reviewer, thank you for your comments of the article. Preserving local genetic resources is a challenge but is of great importance for breeding programmes. Most old Bulgarian cherry cultivars are not kept in collection orchards, and currently it is unknown how many can be traced. Finding these cultivars is primary objective of the team working on KP-06-N46/3 project, assessing the agronomic characteristics and including them in the breeding programme is a work in progress and hopefully will continue in a follow-up project.

Reviewer 3 Report

1- Formulate the purpose of the research (last paragraph of the Introduction)

2- You should improve the introduction (add information about the disease)

3- Add new reference in Discussion section

4- You should improve the conclusion section.

Author Response

Dear reviewer, thank you for your comments of the article.

Point 1. Formulate the purpose of the research (last paragraph of the Introduction)

Response 1: We have improved the “Introduction” section as follows:

During these scientific expeditions, several local cherry forms were discovered without visual symptoms of brown rot and cherry leaf spot. The objective set in this paper is to confirm the degree of field resistance / low susceptibility of the specimens by conducting laboratory tests with artificial inoculations of fruits and leaves. The results would contribute to both the conservation of local genetic resources and enhancement of the sweet cherry breeding programme in the Fruit Growing Institute – Plovdiv, Bulgaria (FGI).

Point 2. You should improve the introduction (add information about the disease)

Response 2: We have improved the “Introduction” section by clarifying research hypothesis, but in our opinion including additional information (morphology, symptoms, life cycle, …) on the two of the most important and widely spread economically important diseases on cherries with divert the focus of the article from genetic resources.

Primary objective of the team working on KP-06-N46/3 project is finding and preserving old local cultivars, as well as assessing the agronomic characteristics and including them in the breeding programme for creation of new market-oriented cultivars with resistance to abiotic or biotic stress factors while preserving the traditional taste.

Point 3. Add new reference in Discussion section.

Response 3: Not applicable

Point 4. You should improve the conclusion section.

Response 4: We have improved the “Conclusions” section as follows:

Reviewer 4 Report

The subject of the article is of interest and concerns the conservation of genetic resources, which is directly related to breeding programs and research in the field of integrated plant protection and organic agriculture.

Author Response

Point 1. The subject of the article is of interest and concerns the conservation of genetic resources, which is directly related to breeding programs and research in the field of integrated plant protection and organic agriculture.