为了建立甘蔗品种黑穗病抗性评价体系,选用9个引进品种,设计一个包括6个对照品种在内的田间试验。首次采用混合小种进行人工浸渍接种,通过整个新植蔗生长季病害进展曲线下的面积、茎感染率和株感染率3个病情指数,以及病害流行学参数潜伏侵染期和持续发病期的分析,对其扰痛性进行评价。在分析以上参数相关程度的基础上,引进了系统聚类分析法进行进一步评价。结果显示;9个引进甘蔗品种中,ROC26属于感病品种,其余属于抗病或高抗品种;3个病情指数和持续发病期的两两相关均为显著正相关,潜伏侵染期与这些参数的相关为负相关,但未达到显著水平;在类间距离大于1.0的条件下,可将15个品种聚为6类,进一步明确了备品种抗黑穗痛性的相似程度;抗性鉴定标准对照种NC0310、F134、NC0376和Ya71—374的应用,明确了接种源为小种1和小种2,通过一次接种试验,明确了供试品种对2个小种的抗性水平,标准对照种的抗性表现,还说明了本生长季发病条件基本是适宜的。本文建立的甘蔗品种抗黑穗病评价体系是切实可行的。
In order to establish the evaluation system of smut resistance for sugarcane varieties, nine introduced sugarcane varieties were chosen and a field experiment including six other control varieties was conducted. By means of manual dipping inoculation, smut resistance for tested sugarcane varieties was evaluated on the basis of analyses on three infected indexes of the area under disease progress curve, infected rate of stalk, infected rate of plant and on two disease epidemic parameters of latent infection period (LIP) and sustained disease duration (SDD). Systemic cluster analyses based on correlation coefficients of these parameters showed that ROC26 was sensitive to smut infection and the other varieties were resistant in nine introduced varieties. Positive significant correlation between three infection indexes and SDD, and negative insignificant correlation between infection indexes and LIP were found. Fifteen sugarcane varieties could be divided into 6 groups on the basis of the distance more than 1.0. It resulted most ot tested sugarcane varieties had similar smut resistance. It suggested that smut race 1 and race 2 were included in inocula and the condition for Ustilago scitaminea infection was suitable in the crop season by setting up the standard varieties of NCo310, F134, NCo376 and Ya71-374 for smut identification. In addition, the results of sugarcane varieties resistant to smut race 1 and race 2 were known by only a simple field trial. From above, a feasible evaluation system for sugarcane smut resistance was established.