Genetic Identification of Hybrid Walnuts (Juglans × intermedia Carr.) in Hungary, the Hidden Potential for Future Breeding

Round 1

Reviewer 1 Report

I would like to congratulate the authors of the manuscript titled “Genetic identification of hybrid walnuts (Juglans × intermedia Carr.) in Hungary, the hidden potential for future breeding”. In a simple way by using only 13 SSR markers, the authors have been able to attain a final result from this research that successfully distinguished individual plants of all the 22 hybrid genotypes as a hybrid group whilst differentiating them from other two walnut groups commonly cultivated in Central or Eastern Europe. As we know, one of the major features of the SSR marker system is that the SSR primer pairs are highly species specific, but the authors have demonstrated that the SSR markers they selected were reliable and informative enough for the putative inter-specific hybrids as well as their original ‘parental’ species. Apart from such SSR genotyping analysis, the authors also present some significant phenotyping information concerning certain intermediate morphological traits, so that the final comparative analyses were supported by both the molecular data and the morphological descriptions. I think research projects like this one that authenticate the hybrid status of  individual plants from a population of tree species in their natural habit via germplasm analysis is quite creative and significant. Indeed, this paper not only highlights the hidden potential for walnut breeding in Central or Eastern Europe, but also provides insight into the effect on genetic inheritance due to possible inter-specific hybridization in some tree species germplasm during the breeding process.  The most obvious work includes the English expression, phraseology and sentence structure especially in the Discussion section.

Author Response

Dear Reviewer 1,

Thank you for reviewing our manuscript. Your comments and opinion highly promote our research and our breeding activity.

Following your suggestion, the Discussion section has been revised in order to improve the interpretation of our findings.

Kind regards,

The Authors

Reviewer 2 Report

The study presented by the authors is quite relevant and very well contextualized. This type of plant material is indeed under-exploited and consequently little studied for the Juglans species. The objectives are clearly presented and the tools used allow to clearly answer the objectives and questions asked by the authors. The analysis of the results and the ensuing discussion is well done and argued. The logical continuation of the work undertaken will consist in characterizing more precisely this plant material. 
The article does not require major corrections. 
In the introduction to line 54-55, the authors mention 3 hybrids developed by the University of Davis, Vlach and VX211 are J Hindsii x J. regia hybrids, the sentence presents some ambiguity on this subject with respect to RX1 which is indeed a J. microcarpa x J. regia hybrid. 

Author Response

Dear Reviewer 2,

Thank you for reviewing our manuscript. Your comments and opinion highly promote our research and our breeding activity.

Following your suggestion, the origin of the mentioned three hybrids has been corrected. The Discussion section has also been revised in order to improve the interpretation of our findings.

Kind regards,

The Authors