Journal of Applied Horticulture. 2002: 4(1): 10-13

Identification of genotypes using leaf isozymes: a study to assess biochemical gene markers in walnut

Dhiraj Vyas; Sharma, A D; Sharma, S K; Sharma, D R

Department of Biotechnology, University of Horticulture & Forestry, Nauni-Solan - 173 230, H.P., India.

Leaf isoenzyme patterns were studied in Juglans nigra and 8 cultivars of J. regia (ACO, Blackmore, Gobind, Hartley, KX Giant, Lake English, Payne and Tutle) for their identification in the field. The results showed differences in specific relative mobility values for the various isoenzymes in walnut cultivars. Of the 6 enzyme systems that were localized on native gels, only esterase and malate dehydrogenase showed wide diversity in Rm values for the different isoenzymes. A total of 16 loci and 24 alleles were observed for 5 enzyme systems, out of which 10 loci were polymorphic. J. nigra was found to be more heterozygous and polymorphic than J. regia. PPO I, PRO I and EST III were found as reliable markers for distinguishing the two species of walnut. The values obtained for similarity coefficient were used to make the dendrogram. Among the cultivars of J. regia, the most diverse relationship was found between Tutle and Blackmore, whereas Blackmore and Payne were the most genetically related.