Studies on factors controlling plant vigor in tomato. An approach to elucidating the eco-physiological properties in horticultural crops

众所周知，旺盛的营养生长阻碍生殖发育，但这种现象的生理和遗传背景尚不清楚。本研究利用数量性状分析(QTL)探讨开花时间的遗传控制。以商品番茄品种茄子与野生种辣椒杂交而成的回交自交系作为作图群体。对114个BC1F4家系在春夏两季进行了表型鉴定。在第1染色体上，在标记C2_At5g49480附近检测到一个主效的DTF(开花天数)QTL，该QTL可解释番茄春季表型变异的40%左右，其贡献等位基因来自番茄。然而，在夏季，这个QTL只解释了16%的表型变异，而位于第3染色体上靠近标记C2_At5g51110的DTF QTL解释了更多的变异。大多数QTL位于第1、3染色体上，其余的QTL分布在第5、7、10染色体上。第1染色体上的DTF QTL与叶长、侧枝数、鲜重等QTL共同定位。该基因座也对应于以前在BC_1群体中定位的DTF、出苗天数和第三叶天数的QTL所在的区域。另一方面，在第3染色体上，DTF QTL与LN(第一次开花前的叶片数)QTL共定位。DtF和LN QTL的共同定位表明，控制这些性状的可能是同一个基因/S。这些结果表明，第1和第3染色体上的DTF QTL可能分别控制着叶片的萌发速度和从营养到生殖的时期。

It is well-known that vigorous vegetative growth hinders reproductive development but the physiological and genetic background of this phenomenon is not clear. In this study, quantitative trait analysis (QTL) analysis was performed to explore the genetic control of flowering time. Backross inbred lines developed from a cross between the commercial cultivar, Solunum lycopersicum and the wild species, S. pimpinellifolium were used as a mapping population. A phenotypic evaluation was done in spring and summer using the 114 BC1F4 families. In chromosome 1, a major DTF (days to flowering) QTL was detected near marker C2_At5g49480, which accounted for about 40% of the phenotypic variation in spring with contributing alleles from S. lycopersicum. However, in summer this QTL was responsible for only 16% of the phenotypic variation, while the DTF QTL in chromosome 3 near marker C2_At5g51110 explained more of the variance. Most of the QTLs were co-located in a single locus in chromosomes 1 and 3, while the other QTLs were sparsely mapped in chromosomes 5, 7 and 10. The DTF QTLs in chromosome 1 were co-located with QTLs for LL (leaf length), LS (number of lateral shoots) and fresh weight (FRW). This locus also corresponds to the same region to which a QTL was previously mapped for DTF, days to emergence and days to third leaf in a BC_1, population. On the other hand, in chromosome 3, the DTF QTL was found to be co-located with QTLs for LN (number of leaves before first inflorescence). Co-localization of DTF and LN QTLs indicates that the same gene/s may be control these traits. These results suggest that the DTF QTLs in chromosomes 1 and 3 probably control the rate of leaf initiation and the period from the vegetative to reproductive stage, respectively.