一种籼稻新矮源的分离和遗传鉴定

 目前生产上推广的半矮生性籼稻品种，均受隐性主基因sd-1控制。为寻找新的矮源，将矮秆籼稻双矮与高秆籼稻品种南京6号杂交，F#-2代中分离出高秆、半矮秆和矮秆（双矮型）三类植株，比例为9∶6∶1，表明双矮的矮秆性状受两个不等位的隐性主基因控制。通过以携有主基因sd-1的半矮秆水稻品种南京11号与F#-2代中的半矮秆个体成对测交和自交分离，获得了一种新的矮秆主基因单独控制的半矮秆系新桂矮。该基因被定名为sd-g。从系谱分析，sd-g渊源于华南晚籼品种桂阳矮1号。sd-g的发现，说明半矮秆籼稻的矮秆基因位点至少有两个，常见半矮秆品种南京11号的基因型可定为sd-1 sd-1 Sd-g Sd-g，高秆品种南京6号为Sd-1 Sd-1 Sd-g Sd-g，新桂矮为Sd-1 Sd-1 sd-g sd-g，双矮为sd-1 sd-1 sd-g sd-g。

A NEW SEMIDWARF GERMPLASM ISOLATED FROM DWARF VARIETY AND ITS GENETIC IDENTIFICATION IN ORYZA SATIVA L. SUBSP. HSIEN

In order to exploit new semidwarf gene which can be used in breeding program in Hsien rice (Oryza sativa L. Subsp. hsien), a dwarf variety, Shuang-ai, was crossed with Nanjing 6, a tall native cultivar. The segregation of F_2 generation showed the ratio 9 tall: 6 semidwarf: 1 dwarf, which meant two semidwarf genes were involved. Nanjing 11, a semidwarf cultivar carrying major gene sd-1, was used as tester to croes with semidwarf plants selected from F_2 generation individually. The isolation of semidwarf genes was conducted in three generations successfully and a new semidwarf line named Xin-Gui-Ai was isolated. The gene being non-allele of sd-1 was named sd-g which can be traced back to Gui-Yang-Ai 1. With two semidwarf genes being found in Hsien rice, the genotype of common semidwarf cultivars, such as Nanjing 11, can be denoted as sd-1 sd-1 Sd-g Sd-g, tall cultivar Nanjing 6 as Sd-1 Sd-1 Sd-g Sd-g and the new germplasm Xin-Gui-Ai as Sd-1 Sd-1 sd-g sd-g, dwarf variety Shuang-Ai as sd-1 sd-1 sd-g sd-g.