玉米粗缩病初显症叶龄与品种抗性关系研究初报

Preliminary study on the relationship between maize resistance to RBSDV and initial symptomatic needling age

针对玉米粗缩病采用传统的以病情指数为评价指标的人工接种鉴定方法存在一定问题,采用田间自然发病法和人工接种法,分析了不同抗性级别玉米自交系‘90110’、‘沈137’、‘DB544’、‘冀35’、‘丹360’、‘黄早四’、‘掖107’、‘掖478’、‘5003’田间自然发病严重度与人工接种发病的初显症叶龄的相关性。结果显示:试验材料田间病指分布在2.85～65.84之间,人工接种致病病株初显症叶龄分布在4～15叶之间,两者之间呈显著负相关(r=-0.923,P<0.01)。通过建立田间发病严重度与人工接种条件下初显症叶龄间的回归方程,制定了以病株初显症叶龄为抗性评价指标的抗性划分标准:初显症叶龄小于6.27的为高感;初显症叶龄在6.27～10.32间的为感病;初显症叶龄在10.32～12.35间的为中抗;初显症叶龄在12.35～13.77间的为抗;初显症叶龄大于13.77的为高抗。新评价指标的采用不仅可以将每材料每重复接种株数从15株减少到3株,同时还将试验调查终止期从19片叶缩短到14片叶。

Traditionally, disease index is taken as the evaluation indicator to identify RBSDV with artificial inoculation identification method. But this way of identification has some short- comings. In order to solve the problems the disease severity of nine maize inbreeds in field and their initial symptomatic needling age when artificial inoculation were investigated, and the cor- relation between the two was analyzed. The results showed that their disease index distributed between 2.85 and 65.84, their initial symptomatic needling age between 4 and 15, and there was a significant negative correlation between the two with r=-0. 923. It may form a new e- valuation indicator for artificial inoculation identification of maize resistance to RBSDV. The new indicator bring a feasibility that not only increase the efficiency of artificial innoculation i- dentification, but also can evaluate resistance in early stage of maize.