HERITABILITY OF BETA-GLUCAN, GROAT PERCENTAGE, AND CROWN RUST RESISTANCE IN 2 OAT CROSSES

Parent-offspring regression was used to estimate heritability for thre e traits (beta-glucan content, great percentage, and resistance to cro wn rust (Puccinia coronata Cda.f.sp.avenae Eriks.) in oat (Avena sativ a L.). The populations used were derived from two crosses, Nova x Mari on QC and Sylva x Marion QC. Marion QC was used as a parent because ot her research had shown that it is relatively high in beta-glucan, a tr ait for which heritability had not previously been estimated. Nova and Sylva are similar in adaptation to Marion QC, and Sylva may be a sour ce of general resistance to crown rust. Random F-5 plants were grown i n a greenhouse, and their F-6 and F-7 progeny were grown in replicated field trials. Heritability estimates for the two grain quality traits were based on regression of F-6 values on F-5 values, F-7 values on F -6 values, and F-7 values on F-5 values. Heritability estimates for be ta-glucan content were between 0.27 and 0.45. The highest estimate was the one based on the F-6 and F-7 generations of Sylva x Marion QC: 0. 45, compared to estimates of 0.32 or less for earlier generations of t he same cross, and to estimates of 0.35 or less for all generations of Nova x Marion QC. Heritability estimates for great percentage were al l between 0.23 and 0.32. The F-6 and F-7 generations were evaluated fo r resistance to crown rust resistance. The Sylva x Marion QC cross see med to segregate for heritable resistance (h(2) = 0.31) but the Nova x Marion QC cross did not (h(2) = 0.07). Several lines from the Sylva x Marion QC cross had low symptoms in both the Fg and F-7 generations. There were no strong genetic correlations among the traits.