高密度SNP标记法解析两个玉米重组自交系穗夹角的遗传基础

Genetic Basis of Panicle Angle from Two Maize Recombinant Inbred Lines Using High Density SNP Labeling Marker

为了探究控制玉米穗夹角的遗传基础,本试验以BYD和MX两个玉米重组自交系群体为材料,采用高密度SNP和连锁分析,对调控玉米穗夹角性状的基因进行QTL定位和可能的功能基因分析。结果表明,穗夹角性状具有较高的遗传性,受基因型和环境的影响。穗夹角经过多环境的调查表明,在两个分离群体中均呈正态分布;共定位到调控穗夹角性状27个QTL,包括5个主效QTL,分别位于2号、4号和7号染色体上,两个来自BYD群体,3个来自MX群体,穗夹角性状QTL的表型贡献率从5.7%(qBYDEA2)到6.9%(qMXEA2-2);进一步通过bin图谱法缩进主效QTL区间,共发掘7个穗夹角性状候选基因,它们主要编码转录调控和代谢的酶。本研究结果首次揭示了玉米穗夹角的遗传基础,并有助于未来通过分子育种应用从而提高玉米优良穗夹角的品种。

In order to reveal the genetic basis on controlling maize panicle angle, two recombined maize inbred lines, BYD and MX were used as materials in this study to carry out QTL location and possible functional gene analysis for the genes regulating maize panicle angle by high density SNP markers and linkage studies. The results showed that maize panicle angle trait was highly hereditary and affected by both genotypes and environments. The multi-environmental survey of panicle angles showed a normal distribution in the two RIL populations. Besides,27 QTLs controlling the panicle angle trait were co-located, including five major QTLs, located on the 2 nd, 4 thand7 thchromosomes, respectively. Furthermore, two QTLs were from the BYD population and the other three were from the MX population, and the phenotypic contribution rate of the QTLs for maize panicle angle trait was from5.7%(qBYDEA2) to 6.9%(q MXEA2-2). Bin mapping method was used to further narrow the major QTL intervals,a total of seven candidate genes for maize panicle trait were identified, which mainly encoded enzymes related to transcriptional regulation and metabolism. The results first revealed the genetic basis of the corn panicle angles,which would help improve the varieties of excellent maize panicle angles through molecular breeding applications in the future.