珍稀濒危植物--云南药用野生稻自然生态群的新发现及其特性

野生稻包括云南药用野生稻(Oryza officinalis Wall.ex Watt.,染色体组CC，染色体数2n=24)是宝贵的基因资源库，自然分布急剧减少。2001年，在云南耿马孟定遮甸新发现了1个药用野生稻分布点，该地药用野生稻植株高度可塑性大，可以根据密度和荫蔽情况自动大幅度调节株高；比其它生态群的结实率高；而其自然发病和人工接种鉴定发现抗稻瘟病能力中等偏上，抗白叶枯病害能力强，抗螟虫和稻飞虱能力也很强。品质分析结果表明该居群药用野生稻蛋白质含量比其它野生稻的高，而直链淀粉含量偏低，说明品质较好。本发现对采取有效措施进行药用野生稻原生地保护，以及试验结果对药用野生稻有利基因的发掘和利用都有重要参考价值。

Charateristics and Discovery of the Newly Found Natural Live Material of Oryza officinalis at Edge of Extinction in Yunnan

Wild rice species belong to a germplasm treasure because they have many good traits and relevant genes which are very useful for development of new rice varieties with resistance to disease. Oryza officinalis Wall.ex Watt (chromosome type CC,2n=24) is one of the important wild rice species.In the past,there were 12 populations of O.officinalis found separately at 12 sites in Yunnan. O.officinalis is now already at edge of extinction.However,in November,2001 we found a new population of O.officinalis locating at Zhedian,Mengding,Yunnan,China.We did investigation on plant characteristics including resistance to white blight disease and blast disease of this population both at original site and another planting site.We also analysed seed nutritional quality of the population.The plants of this population has two significant traits:high seed setting percentage rate and the high flexibility of auto changing the plant height according to their environment while compared with another population of O.officinalis -Genma population and the other wild rice species.Under innoculation of 8 blast fungus strains and 3 typical white blight bacterium strains,the plants of this population showed comparatively stronger resistance to white blight disease.The protein percentage in brown rice of this population is higher than that of other wild rice species.The amylose content in brown rice of this population is lower than that of other wild rice species.This newly found population of O.officinalis has many traits which can be used potentially in rice breeding.