Table_2_Phenotypic and Molecular Selection of a Superior Solanum pennellii Introgression Sub-Line Suitable for Improving Quality Traits of Cultivated Tomatoes.docx

The Solanum pennellii Introgression Line (IL) population can be exploited to identify favorable alleles that can improve yield and fruit quality traits in commercial tomato varieties. Over the past few years, we have selected ILs that exhibit increased content of antioxidant compounds in the fruit compared to the cultivar M82, which represents the genetic background in which the different wild regions of the S. pennellii ILs were included. Recently, we have identified seven sub-lines of the IL7-3 accumulating different amounts of antioxidants in the ripe fruit. Since the wild region carried on chromosome 7 induces a low fruit production in IL7-3, the first aim of the present work was to evaluate yield performances of the selected sub-lines in three experimental fields located in the South of Italy. Another aim was to confirm in the same lines the high levels of antioxidants and evaluate other fruit quality traits. On red ripe fruit, the levels of soluble solids content, firmness, and ascorbic acid (AsA) were highly variable among the sub-lines grown in three environmental conditions, evidencing a significant genotype by environment interaction for soluble solids and AsA content. Only one sub-line (coded R182) exhibited a significantly higher firmness, even though no differences were observed for this trait between the parental lines M82 and IL7-3. The same sub-line showed significantly higher AsA content compared to M82, thus resembling IL7-3. Even though IL7-3 always exhibited a significantly lower yield, all the sub-lines showed yield variability over the three trials. Interestingly, the sub-line R182, selected for its better performances in terms of fruit quality, in all the trials showed a production comparable to that of the control line M82. A group of species-specific molecular markers was tested on R182 and on the parental genotypes in order to better define the wild genomic regions carried by the elite line R182. In these regions three candidate genes that could increase the level of AsA in the fruit were identified. In the future, the line R182 could be used as pre-breeding material in order to obtain new varieties improved for nutritional traits.

潘那利番茄（Solanum pennellii）渐渗系（Introgression Line, IL）群体可被用于挖掘能够改良商业番茄品种产量与果实品质性状的优良等位基因。过往数年间，我们已筛选出若干渐渗系，其果实抗氧化化合物含量相较于遗传背景亲本栽培品种M82显著提升——所有潘那利番茄渐渗系均以M82作为标准遗传背景，整合了来自该物种的不同野生基因组片段。近期，我们鉴定得到IL7-3的7个亚系，其成熟果实的抗氧化物质积累量各不相同。由于7号染色体上携带的野生基因组片段会导致IL7-3果实产量偏低，本研究的首要目标是在意大利南部的3个试验田中评估这些筛选出的亚系的产量表现。本研究的另一目标是验证同批亚系的高抗氧化物质水平，并对其他果实品质性状开展评价。对红色成熟果实的检测结果显示，在3种环境条件下种植的各亚系，其可溶性固形物含量、果实硬度及抗坏血酸（ascorbic acid, AsA）水平均存在显著差异；其中可溶性固形物与抗坏血酸含量表现出显著的基因型×环境互作效应。仅有编号为R182的亚系展现出显著更高的果实硬度，尽管亲本系M82与IL7-3之间该性状并无显著差异。与M82相比，该亚系的抗坏血酸含量显著提升，这一特性与IL7-3一致。尽管IL7-3的产量始终显著低于对照，但所有亚系在3次田间试验中的产量均存在变异。值得关注的是，因果实品质表现优异而筛选得到的R182亚系，在所有试验中的产量均与对照M82相当。我们使用一组物种特异性分子标记对R182及其亲本基因型进行检测，以更精准地界定该优良品系所携带的野生基因组区域。在这些区域中，我们鉴定出3个可能提升果实抗坏血酸含量的候选基因。未来，R182可作为预育种材料，用于培育营养性状得到改良的新型番茄品种。