Distinguishing Indian commercial wheat varieties using RAPD based DNA fingerprints

Abstract

Wheat is a major contributor to food self-sufficiency in India. A large number of varieties have been bred over years to sustain higher production levels. These varieties have been described primarily by morphological characteristics, which show stage and tissue specific expression, and interaction with environment. The present study was undertaken to test the efficiency of RAPD in distinguishing and determining the extent of genetic relatedness among 96 varieties belonging to Triticum aestivum, T. durum, T. dicoccum and Triticale, using 50 random decamer primers. Eighty-two per cent of these primers and 78.8% of the amplified fragments were found to be polymorphic. The number of polymorphic fragments per primer ranged from 1-13 with an average of 4.92. The varieties could be unambiguously distinguished from each other by RAPD profiles based on all the 50 as well as 10 most informative primers, which detected more than 5 polymorphic fragments each. The estimated probability of identical match by chance suggested that the RAPD based DNA fingerprints can be used with high degree of confidence for establishing distinctness of the varieties. Average similarity (75%) among the hexaploids was the same as in the tetraploids, although the range was broader in case of the former group of varieties. This suggested a relatively narrow genetic base of the tetraploid varieties as compared to the hexaploids. Cluster and principal component analysis clearly distinguished the tetraploids from the hexaploids.