ABSTRACT

The QTL mapping for gynoecy in cucmber (Cucumis sativus L.)was carried out by using backcross populations (BC₁F₂ & BC₁F₃) of a cross using two inbred lines; one monoecious with multiple (≥ 5) lateral branching habit cv. Pusa Uday (Indian slicing type) and gynoecious exotic line Gy14 (American pickling type) with few lateral branches (1–2). QTL detection was performed by employing QTL Ici mapping software (version 4.1) of the two mapping populations. We detected seven gynoecious QTLs in two genomic regions (chromosome 5 and 6), on which three significant QTLs (qGyn 5.1, qGyn 6.5 and qGyn 6.6) had higher LOD score (10.5, 26.2, and 24.5) and phenotypic variance (5.9, 14.5 and 14.5%) in BC₁F₂ population. However, two significant QTLs (qGyn 5.1 and qGyn 6.1) accounted for gynoecism which could explain 22.90 and 12.88% of the phenotypic variation with the LOD score of 15.86 and 11.82 in linkage group 5 and 6, respectively in BC₁F₃ population. Out of 82 simple sequence repeats (SSR) markers, three (SSR00233, SSR15516 and SSR13251) was found tightly linked and flanked to gynoecious trait QTLs (qGyn6.5 and qGyn6.6) in BC₁F₂ population at <1.5 cM, which could be used for marker-assisted selection (MAS) in cucumber improvement programmes. In order to increase the productivity of Indian cucumber, the introgressed Indian gynoecious cucumber lines derived from an exotic genetic background using MAS may be directly used as a variety or parent of hybrid.

摘要

利用两个自交系的回交群体（BC ₁ F ₂和BC ₁ F ₃）对黄瓜（Cucumis sativus L.）的雌性进行QTL定位。一个具有多个（≥5）侧向分枝习性的雌雄同株。Pusa Uday（印度切片型）和雌雄异株Gy14（美国酸洗型），侧枝很少（1-2）。通过使用两个映射种群的QTL Ici映射软件（4.1版）执行QTL检测。我们在两个基因组区域（染色体5和6）中检测到七个雌性QTL，其中三个显着QTL（qGyn 5.1，qGyn 6.5和qGyn 6.6））在BC ₁ F ₂人群中具有较高的LOD评分（10.5、26.2和24.5）和表型差异（5.9、14.5和14.5％）。然而，两个重要的QTL（qGyn 5.1和qGyn 6.1）构成了妇女生殖，可以解释表型变异的22.90％和12.88％，在BC ₁ F ₃人群中，连锁组5和6的LOD得分分别为15.86和11.82 。在82个简单序列重复（SSR）标记中，发现三个（SSR00233，SSR15516和SSR13251）紧密连接，并与BC ₁ F _2中的雌性性状QTL（qGyn6.5和qGyn6 .6）紧靠在一起。种群<1.5 cM，可用于黄瓜改良计划中的标记辅助选择（MAS）。为了提高印度黄瓜的生产力，使用MAS从外来遗传背景衍生的渗入的印度雌核黄瓜系可以直接用作杂种或杂交亲本。