杂草稻的分类地位和利用途径探讨

对海南岛杂草稻和亚洲栽培稻及其近缘野生种的形态特征和生长习性作了对比观察,表明杂草稻虽然易落粒和种子休眠性较强,但它们与伴生的栽培稻如蕊稻（深水稻）在外部形态和叶表皮微形态等上很相似．结合前人研究结果,探讨了杂草稻的来源,指出杂草稻应归入栽培稻籼粳二亚种,作为变种,同时,观察到杂草稻与杂交稻Ｆ１等一样,在叶片远轴面脉间两气孔带之间的几行长细胞中零星分布较多气孔,简称“中气孔”,指出这种异常现象可作为杂合程度的量化指标之一,在选育杂种性品种中有应用价值,杂草稻的杂种性繁殖机制和特异基因值得鉴定、研究和利用．

A Study on Taxonomic Position and Utilization of Weedy Rices

The habit and morphological characters of weedy rices collected in Hainan Island are investigated and contrasted with Orpza sativa L.and close relatives of wild species.The result indicates that though weedy rices are subject to deciduous spikelets and high dormancy of seeds,they are allied to their companion cultivars such as cv.Ruidao(deepwater rice)in the characters of external morphology and leaf epidermis etc.The origin.of weedy rices are discussed with former studies. Weedy rices should be a variety under both subspecies(sativa and japonica)of cultivatied species. Moreover,in weedy rices,like in hybrid rices(F1)etc.,some stomata scattered in the middle long cells except two stomata bands between the veins on abaxial epidermis of leaves,namely "middle stomata".are observed for abnormal distribution of leaf stomata.The authors propose that it could be applied to breeding hybridizable varieties,as a quantitative mark for the level of hybridism. Weedy rices are worth identifying,researching and utilizing for propagating mechanism of hybridism and special gene.