A major QTL introgressed from wild Lycopersicon hirsutum confers chilling tolerance to cultivated tomato (Lycopersicon esculentum)

Abstract

Many plants of tropical or subtropical origin, such as tomato, suffer damage under chilling temperatures (under 10 degrees C but above 0 degrees C). An earlier study identified several quantitative trait loci (QTLs) for shoot turgor maintenance (stm) under root chilling in an interspecific backcross population derived from crossing chilling-susceptible cultivated tomato (Lycopersicon esculentum) and chilling-tolerant wild L. hirsutum. The QTL with the greatest phenotypic effect on stm was located in a 28 cM region on chromosome 9 (designated stm 9), and enhanced chilling-tolerance was conferred by the presence of the Lycopersicon hirsutum allele at this QTL. Here, near-isogenic lines (NILs) were used to verify the effect of stm 9, and recombinant sub-NILs were used to fine map its position. Replicated experiments were performed with NILs and sub-NILs in a refrigerated hydroponic tank in the greenhouse. Sub-NIL data was analyzed using least square means separations, marker-genotype mean t-tests, and composite interval mapping. A dominant QTL controlling shoot turgor maintenance under root chilling was confirmed on chromosome 9 using both NILs and sub-NILs. Furthermore, sub-NILs permitted localization of stm 9 to a 2.7 cM interval within the original 28 cM QTL region. If the presence of the L. hirsutum allele at stm 9 also confers chilling-tolerance in L. esculentum plants grown under field conditions, it has the potential to expand the geographic areas in which cultivated tomato can be grown for commercial production.

Quantitative Trait Loci and Crop Performance under Abiotic Stress: Where Do We Stand?: Table I.

“…QTLs controlling sensitivity to chilling have been identified in maize seedlings (Hund et al, 2005;Jompuk et al, 2005;Presterl et al, 2007), in sorghum seedlings (Knoll and Ejeta, 2008), and in rice at the seedling and booting stages (Andaya and Tai, 2006;Kuroki et al, 2007;Lou et al, 2007). In cultivated tomato (Solanum lycopersicum), a QTL allele introgressed from a wild relative (Solanum hirsutum) increased chilling tolerance (Goodstal et al, 2005). Crops sown in the fall may experience subfreezing temperatures at the vegetative stage during winter.…”

Differential Modulation of Photosynthesis, Signaling, and Transcriptional Regulation between Tolerant and Sensitive Tomato Genotypes under Cold Stress

“…In the past decade, many physiological responses to cold stress were comparatively analyzed between S. habrochaites and S. lycopersicum , for review see [5]. Although several hypotheses have been proposed to explain tolerance or sensitivity to chilling in plants, the physiological mechanisms responsible for cold tolerance remain unclear [7].…”

Enzyme Activity Profiles during Fruit Development in Tomato Cultivars andSolanum pennellii

“…It has been used to study fruit shape and development (Causse et al, 2004;Brewer et al, 2007;Bertin et al, 2009), metabolite composition (Fridman et al, 2004;Tikunov et al, 2005;Schauer et al, 2006;Tieman et al, 2006;Bertin et al, 2009), flowering time (JimenezGomez et al, 2007), disease and fungus resistance (Chaerani et al, 2007;Finkers et al, 2007), tolerance to salinity (Cuartero et al, 2006;Villalta et al, 2007), and chilling (John Goodstal et al, 2005).…”