玉米单倍体诱导系诱导双生苗的观察

以不同玉米杂交种与单倍体诱导系为材料,对从杂交种中诱导双生苗的情况进行了观察。结果表明,在农大108、高油5598、郑单958与CAUHOI-1的杂交当代籽粒中,双生苗的平均频率为0.15%,显著低于单倍体的平均诱导频率3.38%,而在自交籽粒中没有发现双生苗。利用45个双列杂交组合为母本分别与两个诱导率不同的诱导系(CAUHOI01和CAU79)进一步杂交,在杂交籽粒中发现26对双生苗,其中有23对来自于CAUHOI-1的杂交后代。本研究结果表明双生苗诱导与单倍体诱导一样,不仅与诱导系有关,在一定程度上也受母本基因型影响,而二者诱导能力表现趋势不一致。对双生苗类型的观察结果表明,双生苗主要为二倍体-二倍体类型,少数为单倍体-单倍体类型,没有发现单倍体-二倍体类型。SSR分析表明每个双生苗两个体间基因型一致,但部分双生单苗田间生长存在着差异。双生苗的发生与单倍体诱导机理的关系有待于进一步研究。

Observation of twin seedling in maternal haploid induction in maize

Different hybrids and haploid inducers were used as female and male materials to observe the twin-seedling induction from the hybrid kernels crossed with maize haploid inducers.The results showed that the average frequency of twin-seedlings from three hybrids crossed with CAUHOI-1 was 0.15%,while the average haploid rate was 3.38%,and no twin-seedling was found from the selfed progeny.Furthermore,26 twin-seedlings were found in 45 diallel hybrids pollinated with two haploid inducers,CAUHOI-1 and CAU79,of which 23 twin-seedlings were from the progeny of CAUHOI-1.These indicated that twin-seedling induction,which was similar to haploid induction,was mainly stimulated by the haploid inducers with some degree influences from the female parents,but the two induction rates performed inconsistent trend.Most of the twin-seedlings were diploid-diploid and a few of haploid-haploid,no haploid-diploid was found.SSR analysis showed that both seedlings in one twin-seedling had same genotype,and some have different agronomic performances.