中国板栗品种对疫病的抗病性评价

通过在板栗离体枝条上接种栗疫病病原菌,对感染后的病斑进行观察,结果表明:不同板栗品种对疫病菌的感染程度不同,在供试的２１个品种和类型中,病斑较小的品种(类型)主要有北峪２号和兴隆城９号,其次为野生板栗、渤海所１８、燕魁、短花栗等７个品种和类型,以上品种抗病性较强,抗病性强的品种占供试品种的３３．３%;抗病性弱的品种有红光栗、怀黄、怀九等,抗病性弱的品种占取样量的３８．１%,以红光栗抗病性最弱,病斑面积显著地高于其它品种。不同生态品种群中均有抗性强的品种和抗性弱的品种。不同品种在感染病菌后对病菌的抗扩展能力不同:红光和怀黄品种的抗扩展能力最差,且病斑上病菌的分生孢子多;野生板栗的抗病性强,病菌侵染后有自愈现象;北峪２号和兴隆城９号感染病后病斑扩展速度显著慢于其它品种。通过试验把供试的品种分为抗性强品种、中度抗性品种。中度感病品种和抗性差的品种共４类。通过接种来源不同的毒性菌株,证明不同板栗品种对强毒性菌株的抗病性表现是一致的。

Evaluation of the Resistance of Chinese Chestnut Cultivars to Cryphonectria parasitica

Cryphonectria parasitica (Murr.) Barr.is presently the most important pathogen affecting Genus Castanea.To de-tect tree resistance would be helpful to select blight-resistant chestnut trees for hyhridization and propagation.Twenty-oneChinese chestnut cultivars were used for evaluating their resistance to Cryphonectria parasitica by inoculated with two viru-lent isolates.The results showed that the canker of 'Beiyu No.2' and 'Xinglongcheng No.9' were the smallest in six weeksand the canker expanded rather slowly after inoculation,they expressed the highest blight resistance to Cryphonectria para-sitica.The eultivars'Bohaisuo No. 18', 'Yankui', wild Castanea mollissima and' Duanhuali' were the higher resistant cul-tivars and species.The high resistant and moderate-high resistant cultivars were in the ratio of 33.3%; the cankers expandedslowly,some of the canker could be eicatrized such as wild Castanea mollissima. The most sensitive cultivars were Hong-guang, its cankers were significant larger than that of others. The canker expansion speed of'Hongguang' and 'Huaijiu'were higher,and more conidiophore were in the canker. The susceptible cultivars were in the ratio of 38.1%.The cultivars orvarieties could be divided into four groups:high resistant cultivars,moderate-high resistant cnltivars,moderate-sensitivecultivars and susceptible cultivars.The test also showed the resistance of cultivars was coincident after inoculating two viru-lent strains of Cryphonectria parasitica.