高温下花红苋和绿叶苋叶片生理特性变化的比较

Comparison of Physiological Characteristics in Leaves of Amaranthus tricolor L. ‘Red flower’ and ‘Green leaf’ under High Temperature

摘要:

40℃连续6 d处理苋菜(Amaranthus tricolor)两个栽培品种花红苋和绿叶苋，探讨热胁迫下它们生理特性的改变。结果表明：与绿叶苋相比，高温下花红苋叶中可溶性糖和脯氨酸含量明显增加，PPO(多酚氧化酶)和POD(过氧化物酶)活性增强，苋菜红素显著积累。绿叶苋对高温表现敏感，苋菜红素含量在处理2 d后明显降低，膜脂过氧化产物丙二醛和质膜透性均高于花红苋，叶片呈现较明显的氧化漂白症状。与常温对照相比，高温下两种苋菜的总酚含量变化不大。热胁迫下花红苋积累较多的苋菜红素和渗透调节物质，酶活性提高，可能是其对高温逆境具有较好耐受能力的生理基础。

Abstract:

The changes in some physiological characteristics in two cultivars of Amaranthus tricolor L., such as ‘Red flower’ and ‘Green leaf’, were investigated under 40℃ for 6 days. The results showed that the contents of soluble sugar and praline, the activities of polyphenol oxidase (PPO) and peroxidase (POD) were enhanced in ‘Red flower’ under high temperature, compared with ‘Green leaf’, while amaranthine content in ‘Red flower’ was remarkably accumulated under 40℃. The ‘Green leaf’ exhibited sensitively to high temperature, in which the content of amaranthine decreased, malondialdehyde (MDA) content and membrane leakage rate increased, as well as the visible damage symptom appeared during heat stress. In comparison with, the content of total phenolic in leaves of two cultivars under 40℃ had no significant difference from that in the control under 30℃. It was suggested that the accumulation of osmoregulatory matter and amaranthine, and enhancement of the activities of enzymes might be the physiological basis of ‘Red flower’ resistanted to heat stress.