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了生殖发育，但这一现象的生理和遗传背景尚不清楚。本研究通过数量性状分析（QTL）探讨了开花时间的遗传控制。利用商业栽培番茄茄（Solunum lycopersicum）与野生品种S. pimpinellifolium杂交而成的回交自交系作为定位群体。在春季和夏季对114个bc14f4家族进行表型评价。在1号染色体上，在C2_At5g49480标记附近检测到一个主要的DTF（开花天数）QTL，该QTL占春季表型变异的40%左右，贡献等位基因来自番茄葡萄。然而，在夏季，这个QTL只负责16%的表型变异，而3号染色体上靠近标记C2_At5g51110的DTF QTL解释了更多的变异。大部分qtl分布在1号和3号染色体上，其余qtl分布在5号、7号和10号染色体上。1号染色体上的DTF qtl与叶片长度（LL）、侧枝数（LS）和鲜重（FRW） qtl共定位。该位点也对应于先前在BC_1群体中定位的DTF，出芽日和第三叶日的QTL的相同区域。另一方面，在第3染色体上，发现DTF QTL与LN（首次花序前叶数）QTL位于同一位置。DTF和LN QTLs的共定位表明可能是同一基因/s控制这些性状。这些结果表明，1号染色体和3号染色体上的DTF qtl可能分别控制着叶片起始率和营养期到生殖期的时间。

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.