Abstract:

In the early 21st century, weedy rice occurred just in some regions of Jiangsu Province. But it has already been popular in the whole province by far, which caused serious damage to high and stable yield of japonica rice. In order to reveal the mechanism of rapid occurrence of weedy rice and control it in rice production, the spreading pattern and the indica-japonica geographical distribution were analized. We collected 205 accessions of 58 weedy rice populations from 58 sites at 13 cities in Jiangsu Province. The samples have been planted in the paddy field of Jiangpu Farm of Nanjing Agricultural University. 38 morphological traits and 6 Cheng's index traits were measured. Euclidean Distance clustering analysis showed that weedy rice followed a mutual-spread pattern in 13 cities. The indica-japonica geographical distribution of weedy rice showed that indica and indica-clinous type weedy rice distributed in 58 sites, accounting for 54.15% and 42.40% of the total samples, respectively. Japonica and japonica-clinous type weedy rice distributed in only 6 sites, accounting for 0.48% and 2.93% of the total samples, respectively. In addition, the geographical distribution comparison between the indica-japonica weedy rice and indica-japonica landraces showed no corresponding relationship. The vast majority of weedy rice in Jiangsu Province is indica type and japonica type weedy rice takes only a small proportion, which conforms to natural gene flow’s proportion between weedy rice and cultivated rice.

Key words: weedy rice, morphology characters, Cheng’s index, indica-japonica classification

摘要：

21世纪初,杂草稻仅在江苏省局部区域发生,目前已扩大到全省,并对粳稻的高产和稳产造成严重威胁。为了掌握其快速发生机制,便于杂草稻的防除工作,需要进一步明确江苏省13市杂草稻是独立发生还是相互传播,以及江苏省杂草稻籼粳地理分布。采集了江苏省13个市58个样地的58个种群,总计205份的杂草稻样品。所有样品在南京农业大学江浦农场田间种植,并测量了38个形态学性状和6个程氏指数鉴别性状。欧氏距离聚类分析,表明江苏省13个市的杂草稻是相互混杂的。籼粳地理分布表明,江苏省杂草稻主要以籼型和偏籼型为主,籼型和偏籼型杂草稻在全部58个样点中都有分布,分别占样品总量的54.15%和42.40%;偏粳型和粳型仅分布于6个样点(淮安、苏州、盐城与扬州),分别占样品总量的2.93%和0.48%。此外,对比江苏省杂草稻的籼粳地理分布与江苏省地方品种的籼粳地理分布,未显示对应关系。籼粳比例和地理分布揭示了江苏省杂草稻主要为籼型,其中极少数为粳型杂草稻,粳型杂草稻的比例与杂草稻和栽培稻之间的自然基因漂移比例相近。

关键词: 杂草稻, 形态学性状, 程氏指数, 籼粳分类