Analyzing Variances and Correlations of Quantitative Traits in Two Long Term Randomly Mated Soybean Populations.

Effects of long term random mating on genetic correlations and variances is under researched in soybeans [Glycine max (L.) Merr.]. Two populations developed at NCSU were randomly mated (with the aid of genetic male sterility) for 26 generations, followed by 6 generations of inbreeding. Yield tests were grown in 2009 at three locations, each with two replications. Data was collected on flower color, flowering date, maturity date, pubescence color, height, lodging, yield, seed weight, percent protein, and percent oil. Genetic variances, heritabilities, and correlations were determined and compared to previous results of these populations in earlier generations of random mating and to check varieties.

Heritabilities in these two populations were high, many traits having an estimated value over 90%. Less than half of the traits tested were correlated with another trait. Long term random mating should decrease the genetic linkage disequilibrium significantly and current genetic correlations may be assumed to be caused by pleiotropy. Given the significant genetic variances in these two populations and high heritabilities, random mating followed by inbreeding also lead to producing high yielding inbred lines for use in other breeding experiments.