两系杂交稻优势生态型的初步研究

研究了培矮６４Ｓ和Ｎ４２２Ｓ与粳亚种中的东北粳、华北粳、日韩粳、云贵粳、非洲粳、美国稻及籼亚种中的云贵籼、太湖籼、华中籼和Ａｕｓ稻的杂种Ｆ１的产量及产量构成因素的杂种优势，初步确定美国稻、非洲粳、云贵粳以及华北粳中的改良品种是粳稻的优势生态型，太湖籼与云贵籼是籼稻的优势生态型。对籼粳优势生态型的产量优势进行比较发现，Ｎ４２２Ｓ／太湖籼低于Ｎ４２２Ｓ／美国稻，但与Ｎ４２２Ｓ／非洲粳和Ｎ４２２Ｓ／云贵粳相当；培矮６４Ｓ与粳稻优势生态型的优势强于与籼稻优势生态型的优势。两个不育系的优势比较表明，培矮６４Ｓ与各生态型的杂种优势强于Ｎ４２２Ｓ与各生态型的杂种优势。

Studies on Heterotic Ecotypes for Two line Hybrid Rice

The heterotic ecotype for two line hybrid rice was studied by analysis of the heterosis of F 1 hybrids between two two line MS lines, Pei'ai 64S and N422S, and 6 ecotypes including Northeast ecotype, North China ecotype, Japan Korea ecotype, Yunnan Guizhou ecotype, Africa ecotype and America ecotype, in japonica subspecies and 4 ecotypes including Yunnan Guizhou ecotype, Taihu ecotype, Middle China ecotype and Aus, in indica subspecies. The results showed that America ecotype, Africa ecotype, improved varieties in North China ecotype and Yunnan Guizhou ecotype might be the heterotic ecotypes in japonica subspecies, while Taihu ecotype and Yunnan Guizhou ecotype the heterotic ecotypes in indica subspecies. The comparison of yield heterosis of the heterotic ecotypes in indica and japonica subspecies showed that N422S/Taihu ecotype (indica) was lower than N422S/America ecotype (japonica), but near to N422S/Yunnan Guizhou ecotype (japonica) and N422S/Africa ecotype (japonica). The heterosis between Pei'ai 64S and its heterotic ecotypes in japonica subspecies was superior to that between Pei'ai 64S and its heterotic ecotypes in indica subspecies. It was also found that the heterosis between Pei'ai 64S and various ecotypes in indica and japonica subspecies was stronger than that between N422S and various heterotic ecotypes in indica and japonica subspecies.