控制高粱分蘖与主茎株高一致性的基因定位

用分蘖与主茎株高一致的高粱品系K35-Y5与分蘖明显高于主茎的高粱恢复系1383杂交, F1自交获得F2分离群体,构建两混池,采用BSA (bulked segregation analysis)和SLAF (specific length amplified fragment sequencing)技术将高粱分蘖与主茎株高一致基因定位。遗传分析表明,分蘖与主茎株高一致性状由1对隐性核基因控制。参考已公布高粱基因组设计酶切方案,构建SLAF文库并测序。对高粱参考基因组序列进行电子酶切预测,确定限制性内切酶为Rsa I+Hae III,酶切片段长度为364～414 bp;测序Q30为91.70%, GC含量为45.79%,达到测序要求;与水稻的测序数据相比,高粱的双端比对效率为93.35%,酶切效率为90.60%, SLAF建库正常。共获得30.80 M reads,开发出133,246个SLAF标签,再通过分析SLAF标签的多态性,检测到319,428个SNP位点。利用SNP-index法和Euclideandistance法及取两者交集进行关联分析,最后得到一个关联区域,位于第9染色体上的54,788,026～56,740,873区间内,关联区域长度1.95 Mb。分析关联区域内的基因在2个亲本之间SNP,对这些SNP进行变异的注释,发现4个非同义突变的SNP。经验证,这4个SNP位点和分蘖与主茎株高一致性状相关。对应到Sobic.009G197901.1、Sobic.009G213300.1和Sobic.009G221200.1三个基因上,这些基因可能是与性状直接相关的功能基因。

Mapping of genes confessing same height of tiller and main stem in sorghum

In this study, an F₂ population derived from a cross between two sorghum lines with same height and different heights of tiller and main stem respectively was used to construct pools. In order to map genes related to same height of tiller and main stem, BSA and SLAF-seq technique were developed. Genetic analysis showed that the trait of same height of tiller and main stem was controlled by a single recessive nuclear gene. Reference genome of sorghum was used to design markers by simulating the number of markers produced by different enzymes. The SLAF library was conducted and sequenced by paired-end sequencing. The restriction enzyme was Rsa I + Hae III. The fragment length was 364-414 bp. The quality of Q30 was up to 91.70% and the GC content (45.79%) was low enough to perform sequencing. Compared with the sequencing data of rice, the construction of SLAF library fitted well to the standard, with its paired-end mapped reads reaching to 93.35% and normal digestion ratio reaching to 90.60% in sorghum. In total of 30.80 M reads and 133,246 SLAF labels were obtained and 319,428 SNPs were found. The associated region was located by SNP-index, Euclidean distance, and their combination. The candidate regions had a size of 1.95 Mb at nucleotides 54,788,026-56,740,873 on Chr.9. The SNPs locating at the associated region were analyzed between the two parents. Four non-synonymous-coding SNPs were found in this region. By verification, these SNPs were considered to be related to same height of tiller and main stem. Corresponding to three candidate genes (Sobic.009G197901.1, Sobic.009G213300.1, and Sobic.009G221200.1), these genes may be functional genes directly related to the traits.