菜豆苗期抗锈性鉴定方法及种质资源的抗性筛选

RUST RESISTANCE IDENTIFICATION METHOD AND THE SCREENING OF RESISTANCE AMONG SOME CHINESE SNAP BEAN GERMPLASM RESOURCES

多种环境因素影响病原菌的致病性和寄主的抗病性，从而对抗病性鉴定和筛选的准确性产生影响。苗期人工接种温度超过28℃，保湿时间少于6h，接种时连续光照等都影响菜豆锈病菌的萌发和侵入。接种浓度过低（<10^3个孢子／ml)或过高（>10^5个孢子／ml)、接种的苗龄过大（超过叶片展平期）及接种的不同部位（叶正、背面）也都对菜豆的抗性表现产生严重影响。菜豆锈病菌虽为专性寄生菌，但其保存方式简单（夏孢子保存于4℃冰箱内），且可较长时间保存（至少9个月）。作者根据这些影响因素提出了菜豆苗期抗锈性鉴定方法，并对我国260份菜豆种质资源进行了抗锈性筛选。结果表明，我国菜豆种质资源的抗锈性类型丰富，这一结果为菜豆的生产和抗病育种研究提供了可利用的品种或材料。

The pathogenicity or virulence of snap bean rust fungus and the resistance of the host were affected by various factors. Germination rate of urediniospore and penetration of the germ tubers were reduced by adult leaves, higher temperature (above 28℃), shorter duration of dew time (shorter than 6h) and continuous lightening during germ tube' s penetration. Resistance of host changed with the inoculum concentration, i.e. , less than 103 spores/ml or more than 105 spores/ml were both not suitable. The infection frequency decreased also in correlation with different inoculated sites such as adaxial or abaxial side of the leaf. Although U. appendiculatus is a kind of obligate parasite, the method to keep its virulence in vitro is very simple. The urediniospores can be stored in a refrigerator at - 4℃ and conserved for a longer period of time, i.e. , 9 months. A rapid reliable and efficient method for screening snap bean resistance to rest was reported. 260 accessions of snap bean were screened for their rust resistance. The result indicated that there were different types of bean cultivars that resisted to U. appendiculatus in our country's snap bean accession.