玉米自交系耐密性的SNP标记发掘

以238份玉米自交系为试验材料，设置两个种植密度水平，研究不同密度对农艺性状的影响，筛选用于评价玉米自交系耐密性的指标并建立耐密性评价体系。结合关联分析找到相应的SNP标记，将标准化值变异系数较大的指标作为耐密性指标。结果表明，单株产量降幅、秃尖长差值、ASI差值可作为玉米自交系耐密性评价指标。利用建立的评价体系从本试验材料中筛选10个耐密性材料，包括B283-1、良玉S122、丹黄212、L201、D25-2-1-1-1、pr07007-1、pr07438-2-2-1、黄早四、SN7135和Y32-1-1-1-1-1。两个环境条件下，共检测到单株产量相关联的4个较重要的（-Log p>3.0） SNP标记，位于第3、4、5和9染色体上；检测到秃尖长相关联的13个较重要的（-Log p>4.5） SNP标记，位于第1、4、7和10染色体上；检测到ASI相关联的12个较重要的（-Log p>4.5） SNP标记，位于第1、4和8染色体上。

Identification of SNP Marker Association with Density-tolerant Characteristics in Maize Inbred Lines

This research was carried out with 238 maize inbred lines as testing materials under two different densities(75 000 and 135 000 plants/ha). The indexes used to evaluate the density tolerance of maize inbred lines were screened and the evaluation system of density tolerance was established. The corresponding SNP markers were found by association analysis. The index with large variation coefficient of standardized value was used as the density tolerance index. The results showed that the yield decline per plant, bald tip difference, and ASI difference could be used as indexes to evaluate density tolerance of maize inbred lines. According to an evaluation system, 10 density-tolerant materials were selected, including B283-1, LiangyuS122, Danhuang212, L201, D25-2-1-1-1, pr07007-1, pr07438-2-2-1, Huangzaosi, SN7135, Y32-1-1-1-1-1-1. Under the two environmental conditions, four significant SNP molecular markers(-Log p>3.0) association with yield were detected, which were located on chromosome 3, 4, 5 and 9. Thirteen significant SNP molecular markers(-Log p>4.5) association with bald tip difference were detected, which were located on chromosomes 1, 4, 7 and 10. Twelve more significant SNP molecular markers(-Log p>4.5) associated with ASI differentials were detected, and located on chromosomes 1, 4 and 8.