Amrita Singh, B. G. Rossnagel, G. J. Scoles, R. A. Pickering
Tóm tắt
Scald resistance breeding requires identification and incorporation of novel resistance sources into local breeding populations. A New Zealand barley Hordeum vulgare L.) line (926K2/11/1/5/1) was evaluated in scald [Rhynchosporium secalis (Oud.) J.J. Davis] nurseries at Lacombe and Edmonton, Alberta, Canada, as a potential source of scald resistance derived from H. bulbosum. Primary objectives were to evaluate the level of resistance in 926K2/11/1/5/1 under Canadian conditions and determine its mode of inheritance. In western Canadian nurseries, 926K2/11/1/5/1 exhibited moderate resistance. 926K2/11/1/5/1 was crossed with the scald-susceptible cultivar CDC McGwire and resulting progeny (F2 and F4:5 recombinant inbred lines) were tested for normality of disease reaction distribution, and were used to estimate the number of effective factors controlling the resistance. F1 plants expressed an intermediate scald reaction compared with the parents. F2 and F4:5 data were normally distributed. Estimation of the number of effective factors using the Castle-Wright formula indicated that resistance from 926K2/11/1/5/1 is quantitatively inherited, but controlled by relatively few genes. The moderate scald resistance in 926K2/11/1/5/1 is an additional resistance source plant breeders can utilize. Key words: Barley, scald, quantitative resistance, Hordeum bulbosum
