根皮苷对平邑甜茶幼苗生理特性的影响

 【目的】探讨不同浓度根皮苷对平邑甜茶幼苗生理特性的影响。【方法】以平邑甜茶幼苗为试材，研究砂培条件下，不同浓度根皮苷对幼苗生物量和生理特性的影响。【结果】根皮苷浓度为0.001 mmol•L-1时促进幼苗生长，浓度达到1 mmol•L-1时开始抑制幼苗的生长，降低了干物质积累。随着处理浓度的增加，抑制作用加强。用浓度为1 mmol•L-1的根皮苷处理幼苗，叶片和根尖的超微结构受到破坏。保护性酶活性在处理初期提高，随着根皮苷浓度的增加和处理时间的延长，超氧化物歧化酶（SOD）活性一直增加，过氧化物酶（POD）、过氧化氢酶（CAT）活性先上升后下降，丙二醛（MDA）含量增加，造成细胞膜伤害，膜脂过氧化。高浓度根皮苷降低了幼苗的光合速率和蒸腾速率。【结论】高浓度根皮苷对幼苗的生长有抑制作用，是造成重茬障碍的重要因素。

Effect of Phloridzin on Physiological Characteristics of Malus hupehensis Rehd. Seedlings

Abstract: M hupehensis seedlings growing in sand were treated with 0.001, 0.1, 1, 10 mmol L-1 of Phloridzin every fourth day for three times. Effect on plant morphology and physiology characteristic was investigated. The results showed that phloridzin improved seedlings growth at 0.001mmol L-1 and inhibited the growth of seedlings at 1mmol L-1.Inhibition rate of phloridzin on seedlings enhanced with higher concentration. At 1mmol L-1 , deformation of the ultrastructures of chloroplast，mitochondrion in leaf and root was observed accompanying with increased MDA content and SOD activity. Activities of POD and CAT increased firstly, then decreased, and then increased again. Photosynthesis rate and respiratory rate of M hupehensis seedlings were reduced at higher concentration of phloridzin.