玉米抗玉米蚜种质的鉴定与抗性位点的定位分析

玉米蚜是世界性的玉米害虫,利用玉米自身的抗性是控制玉米蚜虫危害的重要途径。为培育抗蚜新品种,提高玉米的抗性,首先需要鉴定筛选抗性种质,明确其抗性遗传模式,发掘抗性基因。本研究首先对新收集的国内外玉米种质资源进行抗玉米蚜鉴定,然后采用分离群体分组分析与高通量测序技术相结合的方法,对鉴定出的高抗蚜玉米自交系携带的抗性位点进行了定位分析。结果表明,在98份玉米种质资源中有5份表现高抗玉米蚜,其中高抗蚜自交系32t33的抗蚜性受多基因控制,表现数量遗传特征,测序分析在第3、第5染色体上获得了2个与抗蚜性状关联的区域,其大小分别为19.66和6.34 Mb,并在关联区域初步筛选出5个抗蚜候选基因。本研究结果丰富了玉米的抗蚜基因资源,为最终分离出抗性基因、明确抗蚜的遗传机制和培育抗蚜品种奠定了基础。

Identification of Corn Leaf Aphid (Rhopalosiphum maidis Fitch) Resistance Germplasms and Mapping of Resistance Loci in Maize

Corn leaf aphid (Rhopalosiphum maidis Fitch) is one of the most predominant insect pests in maize fields and causes significant loss of the crop worldwide. The use of insect-resistant germplasms is a very effective and economical way to control this insect pest. In order to develop resistant hybrids for aphid control, it is necessary to identify and screen resistant germplasms, determine genetic pattern of resistance, and explore resistant genes. In the present study, newly collected maize germplasms for corn leaf aphid resistance have been evaluated; the aphid-resistance loci from maize inbred line 32t33 have been identified by employing a combination of bulked segregant analysis and high-throughput sequencing technology. The results showed that 5 out of 98 maize germplasms were highly resistant to corn leaf aphid. The resistance from the inbred line 32t33 is subject to polygenic control and exhibited quantitative genetic characteristics. Two genomic regions on chromosomes 3 and 5 were identified to be associated with corn leaf aphid resistance, with sizes of 19.66 Mb and 6.34 Mb, respectively. Furtherly, five candidate genes associated with the aphid resistance have been initially predicted. The results of this study could help to enrich aphid-resistance maize resources, better understand the maize aphid-resistance mechanism and develop new hybrids with corn leaf aphid resistance.