【摘要】 采用不同抗蓟马特性的苜蓿品系,于不同蓟马虫口密度下测定苜蓿水杨酸含量和虫害程度,以明确苜蓿叶片水杨酸含量与其抗蓟马特性的关系.结果表明,苜蓿叶片游离态、结合态水杨酸含量均与苜蓿抗蓟马特性密切相关;高抗品系(抗蓟马品系)的水杨酸初始含量(0.539 mg·g-1)高于低抗品系(0.403 mg·g-1);与较低抗品系相比,高抗品系受害器官(叶)水杨酸含量随虫口密度和危害点面积的增大而增加相对缓慢,而随危害指数的增大而增加较快(3.84倍).可见,水杨酸主要是间接增强苜蓿对蓟马的抗性;高抗蓟马苜蓿品系能通过快速获得较高水杨酸含量来阻碍被危害伤口的扩大,降低其受危害程度,促使自身产量和品质提高.更多还原

【Abstract】 The relationship between the content of salicylic acid in alfalfa and its anti-thrips property was investigated in detecting the content of salicylic acid and damage level of insect pest according to the different density of thrips in different anti-thrips alfalfa.The results showed that the anti-thrips property of alfalfa was closely related to the free salicylic acid,bound salicylic acid and the total content of salicylic acid.The initial content of salicylic acid in high-level(thrips resistant strains) resistant strains of alfalfa was higher(0.539 mg·g-1) than that of in low-level(0.403 mg·g-1) resistant strains.Contrasting to the lower-level resistant strains of alfalfa,the content of salicylic acid in the damage organ(leaf) of high-level resistant strains of alfalfa was slowly increased with the increasing of the thrips,as well as rapidly improved with the increasing of the damage index(3.84 times).Moreover,the results indicated that high-level resistant strains of alfalfa can reduce the damage of insect pest by obtaining quickly the high content salicylic acid to prevent the enlarge of the damage.Salicylic acid indirectly strengthened the resistance of alfalfa for thrips.更多还原