47份木薯资源对朱砂叶螨的抗性鉴定及其抗性机理的初步研究

Resistance Evaluation and Preliminary Studies on Resistance Mechanism of Tetranychus cinnabarinus for 47 Cassava Germplasms

以47份木薯资源为材料,通过田间螨害情况调查,评价并鉴定木薯品种的朱砂叶螨抗性级别,同时对其中8份不同抗性木薯品种的形态学特征和生理生化特性进行调查及检测,研究木薯对朱砂叶螨的抗性与植株外部形态、叶片营养及生理生化特性的关系。结果表明:47份资源共包含4种抗性级别,分别为R、MR、S和HS,抗性最高的品种为食用木薯品种SC9和ST-1;未发现木薯品种螨害指数与株高、分枝部位、分枝数、叶形、叶片质地、裂叶长、裂叶宽、叶厚等植株形态学特征及氢氰酸含量、单宁含量、粗蛋白含量、可溶性糖含量间的相关关系;螨害指数与SPAD值间呈显著负相关关系,相关系数为-0.741。木薯对朱砂叶螨的抗性可能是各营养成分和生理指标等影响因素综合作用的结果,或者是在某一个指标达到对朱砂叶螨取食性产生作用的临界点时,才会对抗性起决定作用。SPAD值可作为木薯的朱砂叶螨抗性鉴定指标之一。

47 cassava germplasms were taken as the materials to evaluate the resistance level of Tetranychus cinnabarinus of Cassava varieties by investigating the mite damage in the field. And the morphological characteristics, physiological and biochemical characteristics of varieties with a variety of resistance levels were investigated and detected to research the relationship between morphology, leaf nutritional, physiological and biochemical characteristics and resistance level of T. cinnabarinus. The results showed that the 47 cassava germplasms including the four resistance levels, that is R, MR, S and HS respectively, edible cassava varieties SC9 and ST-I had the highest resistance to T. cinnabarinus; the relationship between mites damage index and morphological characteristics such as plant height, branches position, branches number, leaf shape, leaf texture, leaf length, leaf width, leaf thickness and hydrocyanic acid content, tannin content, crude protein content, soluble sugar content had not found. The damage parameters of mites had a significant correlation with SPA D value, the correlation coefficients was -0.741. The resistance to T. cinnabarinuz of cassava may be caused synthetically by factors such as nutrient composition and physiological and biochemical indicators, or the factor in its decision function when it reached the critical value of impact T. cinnabarinus taking diets; SPAD values could be a indicator of evaluating the resistance to T. cinnabarinus in cassava.