旱涝胁迫对薄壳山核桃光合特性和叶绿体超微结构的影响

Effects of drought and flooding stress on photosynthetic characteristics of pecan Carya illinoinensis Wangenh.and ultrastructure of its chloroplasts

以薄壳山核桃1年生实生苗为材料,研究了干旱和淹水胁迫对其光合特性和叶绿体超微结构的影响。结果表明,与淹水胁迫相比,薄壳山核桃幼苗对干旱胁迫更敏感。干旱10 d,薄壳山核桃幼苗叶片即开始萎蔫,光合能力丧失,出现大量溶酶体和嗜锇颗粒;而淹水10 d,幼苗仍保持较高的光合能力,叶绿体超微结构相对稳定;干旱30 d,叶绿体结构完全破坏,大部分细胞器已经破坏溶解;淹水30 d,薄壳山核桃幼苗叶片开始变黄,出现少量褐色斑点,叶绿体肿胀变圆,嗜锇颗粒数量增加,片层结构开始松散。

One-year-old pecan seedlings were adopted as materials to investigate the influences of drought and flooding stress on the photosynthetic characteristics and ultrastructure of chloroplast.Results showed that pecan seedlings were more sensitive to drought than to flooding.After ten-day drought,leaves wilted,photosynthetic ability lost,and lysosomes and osmophores increased sharply,whereas high photosynthetic ability and stable ultrastructure of chloroplasts were detected at day 10 after flooding.Chloroplast structures were completely destroyed,and most organelles were dissolved after thirty-day drought.After thirty-day flooding,pecan leaves turned yellow with spots appearing,accompanied with destruction in ultrastructure of leaves,including swelling chloroplast,increased osmophore and loosened chloroplast lamellae.