稻种遗传资源多样性的开发利用及保护

由于近年来栽培稻众多改良品种的育成和大面积推广，使之在很大程度上取代了地方品种，造成栽培稻基因源的大量基因流失，导致栽培稻品种的遗传基础越来越狭窄以至不能承受新病、虫害和不利环境的袭击。同时，由于人们长期施用杀虫剂、灭菌剂和除草剂等化学农药，严重地恶化了农业生态环境。要改变这种恶性循环的局面，开发和利用稻种的遗传资源，以丰富栽培稻品种的遗传基础是非常必要的。稻种基因源包括了亚洲栽培稻、非洲栽培稻、杂草稻、稻属的野生物种以及稻族内的近缘属种，它们是栽培稻品种进一步改良所不可缺少的遗传资源。但是，由于农业生产模式的改变，社会经济和工业化水平的迅速发展和提高，稻种基因源的多样性受到了严重的影响和威胁。一些野生稻种的居群已经迅速地缩小甚至从原产地消失。因此，对稻种基因源及其多样性进行及时有效的保护，并对其进行合理的开发和利用，是保证栽培稻进一步改良和持久生产的最有效方法。

Diversity of rice genetic resources and its utilization and conservation

The widespread adoption of improved high-yield rice varieties , which in a large scale replaced traditional and local rice varieties , has resulted in a great genetic erosion of the cultivated rice genepool. This process has narrowed genetic background of the cultivated rice. As a result , modern rice varieties become vulnerable and can not stand the attack of new disease and insect pests , and the unfavorable changes of environments. Meanwhile , the long2term use of chemical pesticides and herbicides significantly deteriorated agricultural ecosystem. In order to change this vicious cycle of the rice ecosystem , it is very important and necessary to explore and utilize the genetic biodiversity in the rice genepool to broaden the genetic background of the cultivated rice. The rice genepool encompasses varieties of Asia rice and African rice , weedy rice , wild species of rice in the genus Oryz a , and species in the related genera of the tribe Oryzeae. These are the essential germplasm resources for the further improvement of cultivated rices. However , due to the change of agricultural patterns , rapid development of social economy , industrialization and urbanization , biodiversity of the rice genepool , including wild species of rice , is under threat . Many populations of wild Oryz a species have been extinct from their original sites or are diminishing. Therefore , it is absolutely necessary and essential to strategically safeguard and conserve biodiversity of the rice genepool and to effectively utilize the elite rice germplasm resources in rice breeding programs. This is the only way to guarantee the long2term and sustainable production of rice varieties.