Genetic diversity of walnut for horticultural traits under mid hill conditions

Abstract

Seedling selection and characterization of superior genotypes of walnut in two districts of Himachal Pradesh, Solan and Sirmour were surveyed to identify, select and characterize the prevalent diversity based on growth, flower and nut traits to build a sound database of selected types for future use in crop improvement works. The seedling populations were systematically studied after following UPOV guidelines based on 48 characters. Out of the total, 16 characters were selected to establish a sound and stable database. The quantum of variation observed was categorized in three specific ranges from the total observed variation obtained from evaluation and genotypes classed under each character ranges. Plant height ranged from 4.5-16.5 m, trunk girth 0.5-3.5 m, yield 15-16 kg/tree leaf size (length 20-46 cm, width 20-42 cm), leaflet (length 4-16 cm, width 2-8 cm, leaflet number 4-10, leaf area 250-650 cm2 , catkin number 3.5 - 5.5, nut weight 7-16 g, nut thickness 20-36 mm). Shell thickness 1.25-2. 75 mm, kernel weight 2.5 to 9.25 g, kernel thickness 18-30 mm and kernel percentage 20-65. A database was developed and six promising types were identified and described.