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最近十年来,世界水稻生产中品种组成和栽培技术发生了很大变化。据报导,约有100多种具有熟期适当、光周期反应不敏感、矮秆、分蘖力强、叶色深、叶片挺立特点的改良品种,在世界稻区取代了几百个传统的高秆品种,其种植比例增加到25%以上。由于这些高产品种的推广应用,在栽培上采用了密植,多肥,以及光周期不敏感的早熟品种应用于多熟制等方法,使水稻生产得到了较大发展,与此同时也暴露了一些改良品种易遭受病虫危害的遗传上的弱点。若单靠化学农药控制高密度的害虫和猖獗的病害,既不经济,又会污染环境造成公害。为了解决这一问题,从事水稻育种的科学家们已把主要精力逐步地转移到抗病虫育种上,
In the recent decade, great changes have taken place in the composition and cultivation techniques of rice in the world’s rice production. It is reported that there are about 100 kinds of improved varieties with appropriate mature maturity, insensitive to photoperiod, dwarfing, strong tillering ability, dark leaf color and upright leaves, replacing hundreds of traditional tall stalks Varieties, the proportion of their planting increased to 25%. Due to the popularization and application of these high-yielding varieties, cultivation of rice has been intensively developed, fertilizers and early-maturing varieties insensitive to photoperiod have been applied to methods such as multi-cropping to make a big development in rice production and at the same time expose some Improved varieties vulnerable to pests and diseases of the genetic weaknesses. If pesticides alone are used to control high-density pests and rampant diseases, it will be neither economical nor harmful to the environment. In order to solve this problem, scientists engaged in rice breeding have gradually shifted their major efforts to disease-resistant insect breeding,