黄瓜种子大小遗传分析与QTL 定位

 以种子大小差异显著的黄瓜野生变种‘PI183967’（Cucumis sativus var. hardwickii）和栽培 品种‘新泰密刺’选系‘931’为亲本，通过6 世代混合模型分析方法，研究种子长度和宽度的遗传规律， 并利用包含160 个株系的F9 代重组自交系群体，构建SSR 分子遗传图谱，完成种子长度、宽度及百粒质 量的QTL 染色体定位。结果表明：（1）种子长度与宽度在正、反交6 世代群体中均符合C–0 遗传模型 （加性-显性-上位性多基因遗传模型），且以多基因加性效应为主。（2）构建的永久SSR 遗传图谱，包 含149 个SSR 标记，9 个连锁群，覆盖基因组长度389.2 cM，平均标记间距为2.61 cM。（3）2012 年春季 与2013 年春季共检测到14 个与种子长度、宽度和百粒质量相关的QTL，分布在Chr.2、Chr.3、Chr.4、 Chr.5、Chr.6 染色体上，LOD 值介于2.59 ~ 9.39 之间，可解释7.4% ~ 28.3%的表型变异率，贡献率 ≥ 10.0% 的QTL 位点6 个，占QTL 总数的42.9 %，可在两年中重复检测出的QTL 位点3 个，占QTL 总数的21.5%。

Inheritance Analysis and QTL Mapping of Cucumber Seed Size

The cucumber wild variety‘PI183967’（Cucumis sativus var. hardwickii）and a cultivated cucumber Northern Chinese inbred line‘931’were used as parental materials to construct genetic populations because of their significant difference in seed size. The inheritance of seed length and width was studied by joint segregation analysis using positive and negative six-generation populations. A SSR genetic map was constructed using the RILs to finish QTL mapping of seed length，width and 100-seed weight. Results showed that（1）The inheritance of seed length and width fitted into C–0 model（Additive dominance-epistasis polygene inheritance model）in the positive and negative cross six-generation，and mainly with additive effect of multi-genes（2）A SSR linkage map of cucumber was constructed 149 SSR markers. The map included 9 linkages and spanned 389.2 cM with a mean marker interval of 2.61 cM.（3） 14 QTLs related to seed length，seed width and 100-seed weight were detected 2012 and 2013 spring. These QTLs accounted for 7.4%–28.3% of phenotypic variance were located on Chr.2，Chr.3，Chr.4，Chr.5，Chr.6 with LOD scores of 2.59–9.39. Of all the QTLs，6 QTLs explained over 10.0% of phenotypic variance accounting for 42.9% and 3 QTLs could be detected in different years which accounted for 21.5%.