一、前言水稻与稗草异属植物的远缘杂交,无论在选种实践上和遗传学理论研究上,都有重大的意义。因为稗草不论生长在水田里或旱地上都长得又粗又壮,夺取水稻的养分,遮蔽水稻的光照,侵占稻田的土壤,农民为了拔除田里的稗草,不知曾费了多少工夫?它却仍然长起来,因为稗草的生活力是很强的,它的穗子比水稻大,种子结得又多,又密,特别是栽培饲用的贵州稗草,一穗有2000—3000粒,比本地野生稗草一穗只 I. Introduction The distant hybridization of rice and barnyardgrass is of great significance both in the practice of selection and in the study of genetics. Because barnyard grass grows in the paddy fields or dry land are thick and strong, to seize the nutrients of rice, covering the rice light, invade the soil of rice fields, farmers in order to remove the barnyard grass fields, I do not know how much time worked? It still grows up because the viability of barnyardgrass is very strong, its ears are bigger than rice, the seeds are much more dense and dense, especially for Guizhou barnyard grass, which has 2000-3000 grains per spike , Than the local wild barnyardgrass only a spike