Pomological and phenological characterization, genetic variability and genetic diversity of walnut (Juglans regia L.) genotypes in the Kodaikanal hills of Western ghats
The walnut (Juglans regia L.) is one of the most important temperate nut crops grown in India. The present investigation was conducted to study the variations available in the walnut population found in the Kodaikanal hills of Tamil Nadu. Twelve selected walnut genotypes of seedling origin were evaluated for their phenological and pomological characters. The results revealed that among the genotypes, two of them (JR-7 and JR-11) were early in the first leafing (2nd - 3rd April). Genotypes JR-1, JR-3, JR-7, JR-8 and JR-12 were earlier in harvesting (15th – 20th October) than the other genotypes. High variation for nut and kernel characteristics was also observed among the genotypes evaluated. Genotypes, JR-5, JR-7, and JR-8 were identified as promising as they recorded higher kernel weight (6.00 g), nut weight (12.00 g) and kernel per cent (48%) than other genotypes. Diversity analysis (Mahalanobis D2 statistics method) resulted in a total of five clusters from the 12 walnut genotypes using 10 biometrical traits. More number of walnut genotypes were accommodated in cluster IV and cluster V with three genotypes each whereas cluster I, cluster II and cluster III comprised of two walnut genotypes each. Intra and inter cluster distance of five clusters was assessed and it varied from 1.29 to 10.82 and 7.66 to 21.36. Maximum intra cluster distance was recorded by cluster V (10.82) followed by cluster IV (3.14). Inter cluster distance was high between cluster III and cluster IV (21.36) followed by cluster IV and cluster V (20.55). Principal component analysis of 12 walnut genotypes with 10 quantitative traits resulted in the formation of three principal components viz. PC I, PC II and PC III with eigenvalues of 4.06, 1.84 and 1.44, respectively. These superior genotypes could be used for cultivation or as parents in future breeding programmes.
Keywords: Juglans regia L., walnut, variation, phenological and pomological characters, Kodaikanal
It is certified that:
- The corresponding author is fully responsible for any disputes arising due to the publication of his/her manuscript.
- The article has been seen by all the authors who are satisfied with its form and content.
- The sequence of names of authors in the by-line is as per their relative contribution to this experiment, giving due credit to all scientists who made notable contribution to it.
- All the authors fully understand that inclusion of any other co-authors or exclusion of any co-authors is not possible once the article has been submitted to the journal.
- The corresponding author takes full responsibility for this article.
- The address of the organization where the research was conducted is given.
- The article is exclusive for this journal, and the results reported here have not been sent (and will not be sent during its consideration by this journal) for publication in any other journal.
- Authors agree to abide by the objective comments of referees and do agree to modify the article into a short note as per the recommendation, for publication in the Electronic Journal of Plant Breeding.
- If published in Electronic Journal of Plant Breeding, the copyright of this article would vest with the Indian Society of Plant Breeders, who will have the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in it, and neither we nor our legal heirs will have any claims on royalty.