COMPARISON OF THE OBSERVED AND PREDICTED FREQUENCIES OF TRANSGRESSIVE SEGREGATES FOR YIELD AND RELATED TRAITS IN TWO BREADWHEAT POPULATIONS

Abstract

The genetic parameters estimated in seven basic sets of generation mean analysis and Fl triple test-cross progenies were used to predict the frequency of recombinant inbred lines derivable from Flbreadwheat populations of HarrierXS308and Redpoll XHD 2204 crosses grown over two environments. The validity of predictions was tested by comparing the expected frequency with the observed frequency of transgressive segregates scored on family means of 183 F6lines. These lines were randomly derived through SSD in each of the Fl populations. In majority of cases, a close goodness of fit was achieved between the predicted and observed frequency of recombinant inbred lines. Recombinant inbred lines were obtained exceeding the parental limits for plant height, peduncle length, 1OO-grain weight and days to heading. The skewed distribution observed for predicted frequency of recombinant inbreds was due to the presence of additive X additive type epistatic interaction. The results of the experiments clearly demonstrated that genetic analysis of a characterin earlygeneration of a cross ofbreadwheatcan provide the necessary information to predict accurately the likely outcome of inbreeding in Fl. The breeding strategies for recovery of recombinant inbred lines having desired level of performance has been suggested.