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《Acta Agronomica Sinica》 1984-04
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STUDIES ON THE INDIGENOUS RICES IN YUNNAN AND THEIR UTILIZATION Ⅱ.A revised classification of Asian cultivated rice

Cheng Kaisheng Lu Yixuan Luo Jun Huang Naiwei Lin Guangrond (Yunnan Academy of Agricultural Sciences)Wang Xiangkun (Beijing Agricultural University)  
This article deals with the usefulness of previously adopted systemsin the classification of rice cultivars,and puts forward the following sy-stematic categories:species-subspecies-ecogroup-ecotype-cultivar.The authors have suggested that the cultivated rice should be classi-fied into only two subspecies,i.e.,Oryza sativa L.emond.subsp.hsienTing(indica)and O.sativa L.emond subsp.keng Ting(japonica),asthey were first named by the ancient Chinese people and have come intouse from the Han dynasty to the present.Javanica,nuda,and communis areecogroups belonging to subspecies keng.Ecotypes under each of them areenumerated with brief descriptions.Experimental evidence showed that thejavanica and nuda ecogroups were more primitive than communis.As forsubspecies hsien,in view of different growing habits in tropical countries,the three seasonal types traditionally set up in India,i.e.,aus(sown inspring),aman(sown in summer)and boro(sown in winter)can be ad-opted as main ecogroups.The major criteria discriminating between the hsien and keng subspec-ies are described in some details.They are shape of grain,hairiness ofglume,glume color at heading,and phenol reaction.Any single charact-er,including F_1 fertility,gives no reliable judgement in identifying thetwo subspecies.The best discrimination is due to character combinations.There are a few rice varieties which can not be readily classified asthe hsien or keng type morphologically,and some show high F_1 fertilitywhen cross with both hsien and keng varieties.They are considered to bethe outcome of nonsynchronous evolution between morphological and ge-netic differentiaton,or they may be varieties not fully differentiated intosubspecies.
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