高粱芒基因Awn3.1的精细定位

摘要

The inheritance character of the awnness of sorghum were investigated in F1 and 1 155 individuals of F2 segregation population derived from a cross between awnless cultivar Btx623 and awned cultivar 7361. It was showed that the trait of awnness was controlled by a single recessive gene. The polymorphism of totally 250 SSR markers distributed throughout the genome of sorghum were identified. The polymorphic markers and 22 recessive F2 plants were used to prima-rily map the gene. The gene was located between markers sm03100 and sm03108 on chromosome 3, with genetic distances of 11. 4 cM and 4. 5 cM, respectively. To narrow down the located interval, InDel markers were developed through sequen-cing 7361 and alignment with Btx623, and the mapping population was enlarged to 214 recessive F2 plants. With newly mined InDel markers and enlarged population, the target region harboring Awn3. 1 was finally narrowed down to a 115 kb fragment between markers InDel-1 and InDel-2.%为了确定高粱有、无芒表型的遗传特性，以无芒高粱品种Btx623和有芒品种7361为亲本做杂交，分析了F1植株和F2分离群体中的1155个单株的芒性基因遗传规律，结果显示有芒性状是受1个隐性单基因Awn3.1控制的质量性状。利用覆盖高粱10条染色体的自行开发的250对SSR引物在两亲本间筛选多态性标记，利用这些标记和22个表型有芒的F2隐性单株对芒性基因进行初定位，将目标基因定位在第3号染色体SSR标记sm03100和sm03108之间，与两标记的遗传距离分别为11.4 cM和4.5 cM。为了进一步缩小定位区间，对亲本7361的相关区段进行了测序，与已公布的Btx623序列比对后设计了InDel标记，并把定位群体扩大到214个F2隐性单株。通过扩大群体和开发新的标记，将目的基因Awn3.1精细定位在标记InDel-1和InDel-2之间的约115 kb范围内。