【摘要】 从小麦抗赤霉病的抗源库中,表型转回选择选出RC0、RC1、RC2、RC3等群体,进行两年研究。结果表明:群体抗病性因轮回选择而显著提高。发病穗数和发病率逐轮降低,发病株中发病小穗数也显著减少,平均海轮减少20%左右。群体中抗病植株的频率有增大趋势。穗长、结实小穗数、穗粒数和穗粒重等农艺性状也得到显著改良。千粒重有所降低。群体遗传变异得到较好保持。从基因库中选出抗性增强、农艺性状改善的优良单株机率明显增大。在进一步的轮回选择中,可对抗性改良的同时,对其他农艺性状进行选择,以期改良群体的综合性状。更多还原

【Abstract】 Different cyclical populations RC0, RC1, RC2, and RC3 of the scab-resistance resource gene pool (SRRGP) in wheat and the resistant cultivar Sumai 3 were investigated during two crop seasons 1988-1990 in Nanjing to evaluate the effects of the population improvement. The experimental results showed that the resistance of the population to scab was significantly improved by phenotypic recurrent selection. The number or percentage of diseased male-fertile plants was significantly reduced in the populations. Of these diseased plants, the average of diseased spikelets was decreased by about 20% per cycle and the frequency of plants with R-level resistance tended to increase distinctly. The effects of improvement were significant with spike length, total and seeded spikelets, number and weight of grains per spike, population means of which increased cycle by cycle. However, 1000-kernel weight in RC3 was lower than that in RC1 and RC2,and obvious change of plant height was not found during the recurrent selection for the resistance. The genetic variability of the gene pool was maintainted, and the probability of superior plants obtained with improved resistance as well as some desirable agronomic traits from it was obviously enhanced. It was suggested that both selection for scab-resistance and some agronomic characters should be simultaneously conducted in further recurrent selection programme in order to improve the synthetic performance of the gent pool.更多还原