Department of Plant Breeding and Biometry, Cornell University, 14853, Ithaca, NY, USA.
Theor Appl Genet. 1989 Aug;78(2):210-6. doi: 10.1007/BF00288801.
The potato aphid, Macrosiphum euphorbiae Thomas, is an important pest of tomato, Lycopersicon esculentum Mill., because it transmits tomato viruses and directly reduces crop yields by its feeding. This study was conducted to determine whether the wild tomato species, Lycopersicon pennellii (Corr.) D'Arcy, would be useful as a source of potato aphid resistance for tomato. Type IV trichome density and aphid resistance were assessed in six generations (P1, P2, F1, F2, BC1P1, and BC1P2) from crosses between L. pennellii (LA 716) and two tomato cultivars, New Yorker and VF Vendor. Weighted leastsquares were used in joint scaling tests to estimate the relative importance of gene effects on type IV trichome density and potato aphid resistance of the hybrids. A simple additive-dominance model adequately explained the variation in type IV trichome density. Models which included digenic epistatic effects were required to explain the variation in aphid resistance. Standard unit heritability estimates of aphid resistance in the backcross to L. esculentum were obtained by regression of BC1F2 off-spring families on BC1F1 parents. Regression coefficients and heritability estimates varied between years with the level and uniformity of the aphid infestation. In the 1985-1986 growing seasons, when aphid infestations were uniform, aphid resistance exhibited a moderate level of heritability (29.8% ± 14.1% and 47.1% ± 11.5% in New Yorker and VF Vendor backcross populations, respectively). The non-uniform aphid infestation of 1984 resulted in lower heritability estimates in the 1984-1985 growing seasons (16.1% ± 15.7% and 21.9% ± 14.8% in the New Yorker and VF Vendor backcross populations, respectively). Selection for potato aphid resistance would probably be most efficient if it were delayed until gene combinations are fixed in later generations, because of the large epistatic effects and the low heritability of this trait in seasons with variable aphid infestations.
马铃薯蚜，麦长管蚜，是一种重要的番茄害虫，因为它传播番茄病毒，并通过其取食直接降低作物产量。本研究旨在确定野生番茄种，Lycopersicon pennellii（Corr.）D'Arcy 是否可用作番茄马铃薯蚜抗性的来源。在来自 L. pennellii（LA 716）和两个番茄品种 New Yorker 和 VF Vendor 之间杂交的六个世代（P1、P2、F1、F2、BC1P1 和 BC1P2）中，评估了 IV 型毛状体密度和蚜虫抗性。联合标度测试中使用加权最小二乘法估计基因效应对杂种 IV 型毛状体密度和马铃薯蚜抗性的相对重要性。简单的加性-显性模型充分解释了 IV 型毛状体密度的变异。需要包括双基因上位性效应的模型来解释抗蚜性的变异。通过回归 BC1F2 后代家族与 BC1F1 亲本，获得了回交后代对 L. esculentum 的抗蚜性标准单位遗传力估计值。回归系数和遗传力估计值在不同年份之间有所不同，这与蚜虫侵染的水平和均匀性有关。在 1985-1986 生长季节，当蚜虫侵染均匀时，抗蚜性表现出中等水平的遗传力（在 New Yorker 和 VF Vendor 回交群体中分别为 29.8%±14.1%和 47.1%±11.5%）。1984 年非均匀蚜虫侵染导致 1984-1985 生长季节遗传力估计值较低（在 New Yorker 和 VF Vendor 回交群体中分别为 16.1%±15.7%和 21.9%±14.8%）。如果等到基因组合在后代中固定后再进行马铃薯蚜抗性选择，可能会更有效率，因为在蚜虫侵染变化的季节中，该性状的上位性效应较大，遗传力较低。
