Exploiting genetic diversity of walnut (Juglans regia) from Jammu region of India for export related traits

The present field work was done to study the existing genetic diversity and its exploitation through identifying elite walnut(Juglans regia L.) mother trees from the large number of naturally growing seedling trees in erstwhile Doda district of Jammu region of Jammu & Kashmir state. The field work was done from 2006 to 2012. A total of 63 walnut trees were marked as elite, out of 790 trees visited at 18 locations situated at 1500m-1750m above mean sea level. Out of total collections, 49.20% samples have attractive colour influencing the consumer acceptability. Five collections (BS1207, BT1807, MR0309, MR0509 and GL0109) had kernel recovery of >50%. Wide range of variability was recorded for various nut characters being highest in kernel recovery (18.54-61.40%) with highest coefficient of variation. Nut weight was positively correlated with nut size. The total variance in first principal component was due to nut size and weight while, in second component, it was contributed by kernel recovery. Further, analysis based on export quality traits (prescribed by J&K walnut grower association) lead to the identification of 8 most promising walnut clones, viz. BS1207, PK2707, MR0309, MR0509, MR0809, GL0109, PR0309 and NZ0112. Of these, GL0109 proved best in respect of export related traits and can be developed as a good table cultivar.