Julier Bernadette, Huguet Thierry, Chardon Fabien, Ayadi Radia, Pierre Jean-Baptiste, Prosperi Jean-Marie, Barre Philippe, Huyghe Christian
INRA, Unité de Génétique et d'Amélioration des Plantes Fourragères, BP6, 86600, Lusignan, France.
Theor Appl Genet. 2007 May;114(8):1391-406. doi: 10.1007/s00122-007-0525-1. Epub 2007 Mar 21.
In many legume crops, especially in forage legumes, aerial morphogenesis defined as growth and development of plant organs, is an essential trait as it determines plant and seed biomass as well as forage quality (protein concentration, dry matter digestibility). Medicago truncatula is a model species for legume crops. A set of 29 accessions of M. truncatula was evaluated for aerial morphogenetic traits. A recombinant inbred lines (RILs) mapping population was used for analysing quantitative variation in aerial morphogenetic traits and QTL detection. Genes described to be involved in aerial morphogenetic traits in other species were mapped to analyse co-location between QTLs and genes. A large variation was found for flowering date, morphology and dynamics of branch elongation among the 29 accessions and within the RILs population. Flowering date was negatively correlated to main stem and branch length. QTLs were detected for all traits, and each QTL explained from 5.2 to 59.2% of the phenotypic variation. A QTL explaining a large part of genetic variation for flowering date and branch growth was found on chromosome 7. The other chromosomes were also involved in the variation detected in several traits. Mapping of candidate genes indicates a co-location between a homologue of Constans gene or a flowering locus T (FT) gene and the QTL of flowering date on chromosome 7. Other candidate genes for several QTLs are described.
在许多豆科作物中，尤其是在饲用豆科植物中，地上形态发生（定义为植物器官的生长和发育）是一个重要性状，因为它决定了植物和种子的生物量以及饲草质量（蛋白质浓度、干物质消化率）。蒺藜苜蓿是豆科作物的模式物种。对一组29个蒺藜苜蓿种质进行了地上形态发生性状评估。利用重组自交系（RIL）作图群体分析地上形态发生性状的数量变异并进行QTL检测。将其他物种中描述的与地上形态发生性状有关的基因进行定位，以分析QTL与基因之间的共定位情况。在29个种质以及RIL群体内，发现开花日期、分枝伸长的形态和动态存在很大差异。开花日期与主茎和分枝长度呈负相关。检测到所有性状的QTL，每个QTL解释了5.2%至59.2%的表型变异。在7号染色体上发现了一个解释开花日期和分枝生长大部分遗传变异的QTL。其他染色体也参与了多个性状的变异。候选基因定位表明，7号染色体上的开花日期QTL与CONSTANS基因或成花素基因（FT）的同源基因存在共定位。还描述了几个QTL的其他候选基因。
