Calafiore Roberta, Aliberti Antonietta, Ruggieri Valentino, Olivieri Fabrizio, Rigano Maria Manuela, Barone Amalia
Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy.
Front Plant Sci. 2019 Feb 22;10:190. doi: 10.3389/fpls.2019.00190. eCollection 2019.
The 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 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.
渐渗系（IL）群体可用于鉴定有利等位基因，这些等位基因能够改善商业番茄品种的产量和果实品质性状。在过去几年中，我们筛选出了一些渐渗系，与代表渐渗系不同野生区域遗传背景的M82品种相比，这些渐渗系果实中抗氧化化合物的含量有所增加。最近，我们鉴定出了IL7 - 3的七个亚系，它们在成熟果实中积累了不同量的抗氧化剂。由于位于7号染色体上的野生区域导致IL7 - 3果实产量较低，本研究的首要目标是在位于意大利南部的三个试验田中评估所选亚系的产量表现。另一个目标是在同一品系中确认高水平的抗氧化剂，并评估其他果实品质性状。在红色成熟果实上，可溶性固形物含量、硬度和抗坏血酸（AsA）水平在三种环境条件下种植的亚系间差异很大，这表明可溶性固形物和AsA含量存在显著的基因型与环境互作。只有一个亚系（编码为R182）表现出显著更高的硬度，尽管亲本系M82和IL7 - 3在该性状上未观察到差异。与M82相比，同一亚系的AsA含量显著更高，因此与IL7 - 3相似。尽管IL7 - 3的产量始终显著较低，但所有亚系在三次试验中产量都存在差异。有趣的是，因其在果实品质方面表现较好而被选中的亚系R182，在所有试验中产量都与对照系M82相当。为了更好地确定优良品系R182携带的野生基因组区域，对R182及其亲本基因型进行了一组物种特异性分子标记检测。在这些区域中鉴定出了三个可能增加果实中AsA水平的候选基因。未来，品系R182可作为预育种材料，以获得营养性状得到改良的新品种。
