【摘要】 缺素烟苗表现为生长缓慢,烟苗矮小,叶片少而小;叶片上出现不同的缺素症状;单叶干重以及根、茎、叶干重都有不同程度的减少;有机物质在不同器官中的正常分配比例失调。缺素可加速叶绿素分解,使烟苗叶绿素含量减少。其中叶绿素a的降解比叶绿素b的降解快些,使叶绿素a/b比值减小。缺素可使烟光呼吸下降并改变暗呼吸速率。净光合速率占总光合速率的比值减小而光呼吸与暗呼吸消耗占总光合速率的比值增大。所有这些导致有机物质在各器官分配失调,烟苗生长不正常,出现各种缺素症状。更多还原

【Abstract】 Lack element flue-cared tobacco plants show growth slowly, plants short, leaves shorlen and lack element symptom. The dry weight of single leaf and root, stem, leaves are reduced differ in degree and organic matter drstibutes imbalance in different organs. Chlorophyll in lack element plants is decomposed fast and chlorophyll content is reduced. Decomposition of chla is faster than chlb SO that chlalb is reduced. The ualue of Dr in lack element plants is descend and Dr is changed. The ratio of proportion fo Pnto Pt drops and the ratio of Pr and Dr to Pt increnses. All above lead to organic matter distribute imbalance in organs, plant irregular and show many lack element symptom.更多还原