大豆菌核病鉴定方法比较及分析

COMPARISONS AND ANALYSES ON THE METHODS OF EVALUATING TOLERANCE TO SOYBEAN WHITE MOULD

大豆菌棱病鉴定方法对于大豆菌核病的研究至关重要,本文比较了子叶接种、离体茎段接种、离体叶片接种和离体茎的草酸反应4种大豆菌核病鉴定方法。结果表明:利用子叶接种法接种5 d后所有植株的子叶全部干枯皱缩,10 d后敏感品种合丰25植株开始萎蔫变黄,接种部位周围开始出现白色菌丝;15 d后植株布满白色菌丝;20 d后发病植株开始死亡;而耐性品种MAPLE ARROW出现这些症状的时期较晚,死亡率也较低。离体茎段接种法和离体叶片接种法,基本上体现了大豆菌核病的主要致病特征。在离体茎的草酸接种中,合丰25和MAPLE ARROW对草酸的敏感度明显不同,且受害程度有明显差别,是一种方便快捷而且准确性较高的鉴定方法,对于大量种质资源筛选有着重要意义。

The methods of evaluating tolerance of soybean cultivars to soybean white mould are very important for selection of soybean variety with white mould resistance. Four methods including mycelia inoculation of cotyledons, stems, detached leaf assays and response to oxalic acid were discussed. The results showed that after 5 days inoculating in cotyledons, all of the cotyledons became kraurotic; susceptible cultivar Hefeng 25 became blasted and yellow, and white mycelia appeared in inoculation part 10 days later; all plants with white mycelia 15 da plants with white mycelia died 20 days later. However,the above symptoms appeared ys later; all later in tolerant cultivar MAPLE ARROW and mortality was low. Mycelia inoculation of stems and detached leaf assays basically showed the main processes and characters of soybean white mould, which were effective methods to simulate field disease processes. The results of response to oxalic acid showed significant differences between Hefeng 25 and MAPLE ARROW,it was a convenient and high veracity method for screening of mass germplasm resources of soybean.