RFLP analysis of preferential transmission in interspecific hybrids of Phaseolus vulgaris and P. coccineus.
The inheritance of RFLP markers in interspecific hybrids of Phaseolus vulgaris and P. coccineus was analyzed. Of 280 cDNA probes used, 70%-85% revealed polymorphism between species while intraspecific RFLP ranged from 8% to 37%. Segregation of 63 clearly scorable markers was examined in 177 P. vulgaris x P. coccineus F2's maintained as callus. Preferential transmission of the P. vulgaris alleles was observed for 24 of the 28 loci exhibiting non-Mendelian ratios. Although the segregation ratios at 17 loci fit gametic selection, also other factors such as nuclear-cytoplasmic or embryo-endosperm interactions may be involved. In the reciprocal F2, a relatively high frequency of maternal alleles was recovered for several loci, while the paternal allele was favored at others. The cDNA clone detecting the most extreme segregation, with no P. coccineus type detected among 165 P. vulgaris x P. coccineus F2 progeny, showed high homology to histone H2A genes. The markers were mapped to nine linkage groups. Aggregation of markers with preferential maternal transmission was observed, which could be due to selection of individual chromosomes, although false linkage detection cannot be excluded. The results obtained with RFLPs may explain the skewed distribution of phenotypic traits following interspecific hybridization.
Guo
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Department of Horticulture, Oregon State University, Corvallis 97331.
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D000595:Amino Acid Sequence; D002678:Chimera; D046508:Culture Techniques; D018076:DNA, Complementary; D007887:Fabaceae / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D012150:Polymorphism, Restriction Fragment Length
D018076:DNA, Complementary; D005819:Genetic Markers