瓜类(葫芦科)包括许多经济上重要的水果蔬菜作物,如西瓜,南瓜/南瓜,黄瓜,还有甜瓜.种子大小(SS)是瓜类育种的重要性状,由数量性状位点(QTL)控制。最近的进展已经破译了模型植物如拟南芥和水稻中种子大小变异的几个信号通路,但是对瓜类SS变异的遗传基础知之甚少。在这里,我们对西瓜中鉴定的种子大小QTL进行了文献综述,南瓜/南瓜,黄瓜和甜瓜,并根据它们在各自草案基因组中的物理位置推断14、9和13个共有SSQTL。其中,四个来自西瓜(ClSS2.2,ClSS6.1,ClSS6.2和ClSS8.2),两个来自黄瓜(CsSS4.1和CsSS5.1),其中一个来自甜瓜(CmSS11.1)是主要影响,种子大小和重量的稳定QTL。全基因组序列比对表明,这些主要效应QTL位于不同基因组的同势区域,这表明瓜类作物中一些重要基因的结构和功能可能保守,以控制种子大小。四个西瓜共有SSQTL区域中的基因注释确定了已知在种子大小控制中起重要作用的基因,包括锌指蛋白和E3泛素蛋白连接酶家族的成员。本工作强调了比较分析在理解种子大小变异的遗传基础上的实用性,这可能有助于将来在瓜类中定位和克隆种子大小QTL。
Cucurbits (Cucurbitaceae family) include many economically important fruit vegetable crops such as watermelon, pumpkin/squash,
cucumber, and melon. Seed size (SS) is an important trait in cucurbits breeding, which is controlled by quantitative trait loci (QTL). Recent advances have deciphered several signaling pathways underlying seed size variation in model plants such as Arabidopsis and rice, but little is known on the genetic basis of SS variation in cucurbits. Here we conducted literature
review on seed size QTL identified in watermelon, pumpkin/squash,
cucumber and melon, and inferred 14, 9 and 13 consensus SS QTL based on their physical positions in respective draft genomes. Among them, four from watermelon (ClSS2.2, ClSS6.1, ClSS6.2, and ClSS8.2), two from
cucumber (CsSS4.1 and CsSS5.1), and one from melon (CmSS11.1) were major-effect, stable QTL for seed size and weight. Whole genome sequence alignment revealed that these major-effect QTL were located in syntenic regions across different genomes suggesting possible structural and functional conservation of some important genes for seed size control in cucurbit crops. Annotation of genes in the four watermelon consensus SS QTL regions identified genes that are known to play important roles in seed size control including members of the zinc finger protein and the E3 ubiquitin-protein ligase families. The present work highlights the utility of comparative analysis in understanding the genetic basis of seed size variation, which may help future mapping and cloning of seed size QTL in cucurbits.