Linkage analysis between gene for grain shattering and semi-dwarfing gene and character expression of shattering in rice

半矮秆水稻品种的选育，使世界上许多水稻种植国的产量潜力得到了突破。热带和温带半矮秆水稻品种的半矮秆基因与半矮秆基因SD-1位于同一基因座上。对半矮秆水稻品种太翠1号和粳稻半矮秆品种石兰泥进行了半矮秆与吐丝习性的连锁分析。本研究以高秆粳稻品种诺林29和两个近等基因系SC2、SC4为材料。SC2和SC4分别含有半矮秆基因sd-1和来自台中原生1号和石井的碎裂基因。用无菌外膜基座抗张强度测定仪测定无菌外膜的破碎程度。SC2/Norin 29和SC4/Norin 29 F2代的碎粒习性分离符合3：1的非碎粒遗传比例，表明SC2和SC4分别携带一对控制碎粒习性的隐性基因。SC2/SC4的F_1和F_2表现出与双亲相同的粉碎习性。因此，SC2和SC4被认为具有相同的粉碎基因。在SC2/Norin 29和SC4/Norin 29的F_2代中，观察到半矮秆基因与粉碎基因的连锁关系。两个杂交组合的重组值的加权平均值为13.1%。一个中国半矮秆品种也被证明在第1染色体上含有SD-L和与SD-L连锁的粉碎基因。由此推测，在半矮秆高产品种的育种中，粉碎基因已与SD-L一起传递到多个半矮秆品种中。这个粉碎基因被标记为sh-2。不育外种皮底部的离层在抽穗期之前就出现了。

The development of semi-dwarf rice cultivars has brought about a breakthrough in yield potential of yield in many rice growing countries of the world. It has become apparent that most semi-dwarf rice cultivars in the tropical and temperate regions carry the semi-dwarfing gene at the same locus As the Dee-geo-woo-gen gene sd-1.The linkage analysis between the semi-dwarfism and the shattering habit in both indica semidwarf cultivar Taicuiig Native 1 and japonica semi-dwarf cultivar Shiranui were carried out. The japonica tall cultivar Norin 29 and the two near-isogenic lines SC2 and SC4 were used in this study. SC2 and SC4 have both semi-dwarfing gene sd-1 and shattering gene derived from Taichung Native 1 and Shiranui, respectively. The degree of shattering was measured by an, apparatus for measuring the breaking tensile strength of the base of sterile lemma. The segregation patterns of shattering habit in the F_2s of SC2/Norin 29 and SC4/Norin 29 showed fit to a 3 non-shattering : 1 shattering genetic ratio, indicating that both SC2 and SC4 carry a single recessive gene controlling shattering habit, respectively. The F_1 and F_2 of SC2/SC4 showed the same shattering habit as that of both parents. Therefore, both SC2 and SC4 were considered to have the same shattering gene. The linkage relationship between the semi-dwarfing gene and the shattering gene was observed in the F_2s of SC2/Norin 29 and SC4/Norin 29. The weighted average of the recombination values estimated from the two-crosses was 13.1 %. A Chinese semi-dwarf cultivar was also proved to have the sd-l and the shattering gene linked to the sd-l in the 1st chromosome. From these result, it is assumed that the shattering gene has been transmitted to many semi-dwarf cultivars together with the sd-l in the breeding programs of semi-dwarf high-yielding cultivars. This shattering gene was symbolized sh-2.The abscission layer at the base of sterile lemma was observed before heading time.