Abstract: Inoculated excised leaf tissue from 600 plants of each of 5 alfalfa cultivars were recurrently screened for 6 times for their resistance capacity to Pseudopeziza medicaginis.Five topmost disease resistant plants and five the least disease resistant plants were identified.Together with five plants chosen at random and all their parent cultivars,a field experiment were conducted to compare and evaluate their disease resistnace capacity and dry matter productivity.The result shows that the progeny of the resistant group ascertains significantly lower disease index and higher dry matter yield than the progenies of the disease susceptible and randomgroups and also all their parent cultivars.Thus validating that inoculation of excised alfalfa leaf tissues for selecting the most Pseudopeziza medicaginis resistant strains is a reliable and effective method.

Key words: Grassland science, Alfalfa, Pseudopeziza medicaginis, Screening for resistance capacity

摘要： 对5个苜蓿遗传材料各600株的离体叶,经过6次对苜蓿褐斑病的抗性循环筛选,在每个遗传材料内筛选出最抗病的5株,并用同样方法选出最感病和随机单株各5株以及亲本材料在田间进行抗病性和干物质产量的比较和评价。结果表明,所筛选出的抗病组后代病情指数显著低于原始亲本及最感病株和随机组的后代,并且干物质产量显著高于原始亲本及感病和随机组后代,证明离体叶接种法是苜蓿抗褐斑病株系筛选的高效而可靠的方法。

关键词: 草原学, 苜蓿, 褐斑病, 抗性筛选