| Abstract Detail
Breeding and Genetics Li, Haiyan [1], Beasley, D. [2], Chen, Q. [1]. Cytological and RAPD analysis of interspecific somatic hybrids Solanum pinnatisectum (+) S. tuberosum. THE diploid Mexican species Solanum pinnatisectum (pnt) was used as a source of late blight resistance in somatic hybridization with the dihaploid potato (S. tuberosum, tbr). Genomic in situ hybridization (GISH) analysis showed that most of the produced 2x pnt (+) 2x tbr somatic hybrids carried 72 chromosomes with two copies of pnt genome combined in potato background, while about 20% of the hybrids had 48 chromosomes carrying each of the parent’s complete genome. Those hybrids showed a resistance to late blight similar or higher than that of pnt. However, about 15% of the hybrids did not retain the pnt parent’s high resistance to late blight. GISH revealed a possible loss of individual pnt chromosome(s) in those aneuploid hybrids. More evidence for recombination was obtained by randomly amplified polymorphic DNA (RAPD) analysis with nine RAPD markers specific for the pnt and tbr genome, respectively. Fourteen hybrids differing in terms of their morphology, ploidy and resistance to late blight were analysed for the presence of all 24 pnt chromosomes. Of the 9 markers analysed, one primer OPAA-03 revealed genotype specific bands for each parental line and three common bands for both parents. All the analyzed hybrids displayed a combination of bands corresponding to tbr and pnt confirming their hybrid nature. A few hybrids were found missing one or two of the common bands, which might be due to a rearrangement of the DNA that was induced by electrofusion or tissue culture conditions, or loss of parent’s chromosome(s). This confirms the cytological analysis of the aneuploid hybrids. Further identification of the hybrid for resistance is on going with the newly developed DNA markers closely linked with late blight resistance on chromosome 7.
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1 - AAFC - Lethbridge Research Centre, P.O. Box 3000, Lethbridge, AB, T1J 4B1, CANADA
2 -
Keywords:
Wild Solanum species
S. pinnatisectum
cytogenetics
Molecular markers.
Session: Poster-43
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:379 |
