玉米核雄性不育系7024不育性遗传分析及不育基因初步定位

Genetic Analysis of Sterility and Preliminary Mapping of Sterility Genes in Maize Genic Male Sterile Line 7024

以玉米核雄性不育系7024为研究对象,通过田间可育株/不育株雄花育性鉴定和花药I2-KI染色、品红染色鉴定败育时期,分析不同发育时期花药的生理生化特性。利用自交系Mo17 Ht、B73和17-703与不育株杂交构建3个F2群体和2个BC1F1群体进行遗传分析,利用BSA法对不育基因进行初步定位。结果表明,该雄性不育材料是无花粉型雄性不育,败育时期初步判定为减数分裂期;不育株花药不同发育阶段超氧化物歧化酶(SOD)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性均低于可育株,不育株花药CAT活性在时期3、时期4显著低于可育株,表明抗氧化酶系统的破坏可能导致花粉败育。F2分离群体中可育株数与不育株数的分离比为3∶1,BC1F1群体分离比为1∶1,表明该雄性不育性状应由单隐性细胞核基因控制。

This experiment takes the maize genic male sterile line 7024 as the research object.Through identifying the fertile/sterile plants male flower fertility in field.In addition,the abortive period of anthers were identified by I2-KI and fuchsin staining.The physiological and biochemical properties of anthers at different developmental stages were analyzed.Three F2 populations and two BC1F1 populations were constructed by crossing inbred lines Mo17 Ht,B73,and 17-703 with sterile plants for genetic analysis.BSA method was used to locate the sterility genes.The results indicated that the male sterile material is pollen free,and the abortion period was preliminary determined to be the meiosis period.The activities of SOD,POD,and APX in the pollen sterile were lower than those of fertile plants at different developmental stages.The CAT activity in the anthers of sterile plants was significantly lower than the fertile plants in stages 3 and 4,indicating that the damage of antioxidant enzyme system may lead to pollen abortion.The segregation ratio between fertile and sterile plants in the F2 segregation population is 3∶1.The segregation ratio in the BC1F1 population is 1∶1.This result indicates that this male sterile trait should be controlled by a single recessive gene.