中文摘要：

太湖流域稻作历史悠久，是我国粳稻高产地区之一。但育成品种的遗传基础日趋狭窄，将会给农业生产带来潜在风险。为了有效利用地方水稻资源以扩大改良品种的遗传基础，作者通过调查19个农艺性状，对823个太湖流域粳稻地方品种的遗传多样性进行了研究。结果表明：15个数量性状的变异系数（CV）范围在4．6％（结实率）和33．7％（单株产量）之间。颖壳色、稃尖色、芒型和粒型4个质量性状分别有10、6、5、4种表现犁。19个农艺性状的多样性指数旧，变化范围在0．757（粒型）和1．930（每穗实粒数）之间，平均为1．540。9月10日以后抽穗的品种比9月10日及其以前抽穗的品种具有更丰富的表型变异。主成分分析表明，株高、单株有效穗、每穗总粒数、每穗实粒数、着粒密度、干粒重、单株产量和穗颈长等8个性状是解释太湖流域粳稻地方品种多样性的重要性状。

英文摘要：

The Taihu Lake region has a long history of cultivating rice （Oryza sativa L. sub. japonica） and has a high yield of rice. However, the genetic basis of rice varieties is becoming more and more narrow, which may result in potential risk to agricultural production. In order to enlarge the genetic basis of rice varieties by virtue of local varieties, we examined the genetic diversity of 823 varieties of japonica rice landraces from Taihu Lake region. We found that, among the 19 traits studied, the coefficient of variation of 15 quantitative traits ranged from 4.6% （seed setting rate） to 33.7% （yield per plant）. There existed 10 phenotypes for husk color, 6 for apiculus color, 5 for awn type, and 4 for grain shape, respectively. For the 19 traits, the phenotypic diversity index （H＇） ranged from 0.757 （grain shape） to 1.930 （filled grains per panicle）, averaging 1.540. Phenotypic variance of accessions headed after 10 September was larger than that of accessions headed before 10 September （including this day）. Principal component analysis showed that plant height, panicles per plant, spikelets per panicle, filled grains per panicle, spikelet density, 1,000-grain weight, yield per plant, and panicle neck length were important traits in explaining the phenotypic diversity of japonica rice landraces from the Taihu Lake region.