QTL analysis of maize （ Zea mays L. ） embryo culturing capacity

Chinese. 以18．599（红）和R15组配的F2群体，构建了含88对SSR标记的玉米遗传连锁图谱，覆盖基因组1636．6cM，标记间平均距离为18．6cM。结合幼胚组织培养试验将幼胚发生胚性愈伤组织诱导率和胚性愈伤组织绿苗再分化数作为反映玉米培养过程中胚性愈伤组织诱导力和胚性愈伤组织绿苗再分化力的性状指标，以此调查玉米幼胚培养能力。利用复合区间作图法进行QTL分析，共检测到5个与胚性愈伤组织诱导率有关的QTL，位于第1、3、7和8染色体上，可解释5.25％～23.4％的表型变异；检测到1个与胚性愈伤组织绿苗发生数有关的QTL，位于第3染色体上，可解释表型变异率为13.42％。

English. The good acceptors for maize transgenic engineering are insufficient in China, especially in the southwest mountain areas. The hereditary variation regularity of maize culture capacity is not very clear. The efficiency of embryonic callus induction and the number of regenerated plantlet were used as the characters of the maize culture capacity in this research. A genetic linkage map was constructed using 88 simple sequence repeat （SSR） markers on a maize （Zea mays L. ） population consisting of 202 F2 individuals derived from the cross between the inbreds 18-599 （red） （higher culture capacity） and R15 （lower culture capacity）. The SSR map covers 1 636.6 cM over the ten chromosomes, with an average interval length of 18.60 cM （Fig.3） with software MAPMAKER version 3.0b. The immature embryos from the population of 202 F2：3：4 lines were evaluated in two traits which were in a normal distribution based on the investigated values （Table 1, Fig.1 and Fig. 2）. With the method of composite interval mapping （CIM） described in QTL Cartographer V2.0 procedure, 5 quantitative trait loci （QTL） were identified for efficiency of embryonic callus induction, on chromosomes 1, 3, 7 and 8 respectively, accounting for phenotypic variation from 5.25% to 23.4% （Table 2） ; one QTL was revealed for number of regenerated plantlet on chromosome 3 and explained the phenotypic variation of 13.42% . Combining the marker assisted selection （MAS） method, the necessity and possibility will be enhanced greatly to transferring the high-culture capacity as well as to accurately location, clone and transformation of the main effect QTL of these two characters.