青海湖畔3种高原盐生植物叶绿体淀粉粒的变化特征

Characteristics of starch grains in chloroplast of three alpine halophytes near the Qinghai Lake

以同种非盐生植物作为对照,利用透射电子显微镜对盐胁迫下3种高原盐生植物——鹅绒委陵菜、西伯利亚蓼和灰绿藜叶绿体淀粉粒的变化特征进行了研究。结果表明,在非盐胁迫下3种高原盐生植物其超微结构无明显差异;而在低温及盐胁迫等多种逆境生态条件下,3种高原盐生植物叶绿体中淀粉粒呈现大量积累且增大的趋势,同时它们多呈圆形沿叶绿体长轴,电子密度中间高、四周低的不均匀分布。此外,还发现3种高原盐生植物产生的潴泡与其叶绿体类囊体程度不同的膨大密切相关。据此,我们认为3种高原盐生植物中淀粉粒增大、增多及潴泡的产生,应是青海湖畔盐渍、低温、低气压、强辐射等多种逆境生态条件胁迫下的反应。

The ultrastrueture of chloroplast in the mesophyll cells of three typical alpine halophytes including Potentilla anserina, Po- lygonum sibiricum and Chenopodium glaucum grown at low temperature and in salt marsh near the Qinghai Lake was studied by using the transmission electron microscope. The result showed that the subcellular structure did not differ between the three halophytes under non-stress condition, but there were a lot of starch grains in the chloroplast of three alpine halophytes, which were usually round or oval in shape arranged along the longitudinal axis of chloroplasts, and the whole starch grains were low in electron-density. Meanwhile, the thylakoid of chloroplasts swelled differently, and some of them even became into cisterua. It suggested that the variations of starch grains in the chloroplast of three alpine halophytes stated above were the result of the long-time stress under the adverse ecological fac- tors such as low temperature, low air pressure, strong radiation, salt marsh, etc., and were an adaptation to the environment.