Selection for aneuploid potato hybrids combining a low wild genome content and resistance traits from Solanum commersonii.
A breeding scheme based on the production of progenies with odd ploidy was followed to introduce useful genes from the wild Solanum commersonii (cmm) into S. tuberosum (tbr) genome. Hybrids from 5 x x 4 x crosses were characterized for traits of interest, and selection was assisted by amplified fragment length polymorphism (AFLP) analysis. As expected, most of the hybrids were aneuploids, with a trend towards a low degree of aneuploidy. Despite the fact that aneuploidy has often been associated with a reduction in male and female fertility, most of the hybrids were fertile following crosses with tbr, making it possible to produce viable offspring. A screening for resistance traits deriving from cmm was also carried out. With respect to freezing resistance, the killing temperatures of cold-acclimated genotypes were distributed between the wild and cultivated parental values, with some hybrids displaying an acclimation capacity higher than 3 degrees C. A wide variability was also found for tuber soft rot resistance, and hybrids with high levels of resistance were identified. Selection of hybrids was based on a two-stage scheme that consisted of conventional phenotypic selection followed by an estimation of the wild genome content still present in order to identify hybrids combining noteworthy traits with a low wild genome content. Previously selected cmm-specific AFLPs were used to monitor the degree of wild genome content still present in each hybrid. The percentage of cmm-specific markers ranged from 59% to 91%, with an average value of 75%. AFLP analysis was employed to assist in the selection of valuable hybrids for further breeding efforts.
Iovene
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M
Department of Soil, Plant and Environmental Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy.
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D000064:Acclimatization; D000782:Aneuploidy; D003433:Crosses, Genetic; D005298:Fertility; D005615:Freezing; D018745:Genome, Plant; D006824:Hybridization, Genetic; D007113:Immunity, Innate; D032322:Solanum / Q000235:genetics*; D011198:Solanum tuberosum / Q000235:genetics*