5种谷物胚乳表层细胞的比较研究

Comparison of peripheral endosperm cell development in five cereals

通过光学显微镜及透射和扫描电镜研究水稻、大麦、小麦、高粱、玉米5种谷物胚乳表层细胞的结构。结果表明:胚乳表层细胞的分化具有位置效应,且不同谷物胚乳表层细胞的发育程度不同。一般而言,粒重较大的谷物其胚乳表层细胞比粒重较小的谷物发达。谷物胚乳传递细胞中壁内突皆为肋状内突,其长轴方向与溶质流运输方向一致。玉米、高粱胚乳传递细胞中的肋状内突较大麦、小麦发达。不同谷物糊粉层细胞结构类似,其细胞壁较厚。根据胚乳表层细胞分布位置和结构特点可推测,胚乳表层细胞在养分的质外体和共质体运输过程中起着重要作用,且胚乳传递细胞的结构比糊粉层细胞更适合灌浆物质的运输。

Light microscopy,transmission and scanning electron microscopy were employed to investigate the structure of peripheral endosperm cells（PECs） of different cereals.Results showed that the differentiation of PECs was determined by their surface position,and the development extent of PECs from different cereals was various.PECs in cereals with large grain weight were generally more developed than those in cereals with small grain weight.All wall ingrowths in-endosperm-transfer cells of different cereals belonged to the flange-type wall ingrowths with their long axes consistent with that of the predicted direction of the solute flow.Wall ingrowths in endosperm transfer cells of maize and sorghum were more developed than those of barley and wheat.Aleurone cells of different cereals had the similar structure with thick walls.According to the position and structure features,PECs may play an important role in apoplastic and symplastic transport of nutrients.The structure of endosperm transfer cells is more suitable for the transport of grain filling nutrients than that of aleurone cells.