连作晚稻秧苗徒长的化学调控——2.多效唑控长效应的生理分析

Chemical Control of Seedling Overgrowing in the Continuous Cropping of Late Rice——2.Physiological Analysis of the Growing-Controlling Effect of MET

新型植物生长调节物质——多效唑对连晚秧苗有明显的控长效应。于一叶一心期施用300ppm多效唑,控长率可达30%左右,有效期为4—5周。多效唑的控长效应与相对低温对苗高的影响相似。多效唑对稻苗各器官均有控长效应,可有效地调整秧苗株型,改善秧田群体条件。多效唑的控长效应主要表现为降低稻苗生长速度,是一种植物生长延缓物质。多效唑与外源 GA_3、IAA 等植物激素有拮抗作用,并增强稻苗体内吲哚乙酸氧化酶活性。

In the previous paper,it was pointed out that the use of MET(Mult-EffectTriazole)to rice seedling could reduce it's height.This paper discussed the physiologicalbasis of the growing-Controlling effect of MET.According to the experimental results,the decrease of growth speed in rice seedlingwas the character of growing-Controlling effect of MET.Spraying MET during 1-2 LeafStage of rice seedling could promot the enhancement of IAA-oxidase in the rice Seedling.on the other hand,the antagonism on the growth of rice Seedling between MET andexogenous IAA was observed.The results showed:(1)The MET might be called plant growth retardant(2)The increase of IAA-oxidase activity would reduce endogenous IAA concentrationin rice seedling,the IAA-oxidase which may play a part in Controlling IAA levels ingrowing plant.this was the physiological causes of growing-Controlling effect of MET.