Preliminary studies on sequence elimination of reciprocal allotetraploids from Cucumis hystrix and C. sativus
野黄瓜与栽培黄瓜正反交异源四倍体序列消除的初步研究

During diploidization, sequence elimination in reciprocal allopolyploids often appears variable in different species, suggesting that the nuclear-cytoplasmic interactions play different roles in different polyploid plants. In this study, an amplified fragment length polymorphism (AFLP) analysis was carried out by using thirteen pairs of EcoRI-NN/MseI- NNN selective primers in amplification of the DNAs from reciprocal F1 hybrids of Cucumis hystrix and C. sativus, the synthetic allotetraploids and the diploid parents. The results indicated that extensive DNA sequence elimination was induced by the genomic merge in the allopolyploids. The frequency of elimination of some parental sequences was affected by cytoplasmic factors, the differences from reciprocal crosses were not statistically significant, and the time of elimination (both started in the F1) and the type of elimination were also the same, suggesting that the nuclear-cytoplasmic interactions might not be the main factor causing sequence elimination. In addition, the direction of sequence elimination was not affected by the reciprocal crosses, and the elimination was more common from the C. sativus which has fewer chromosomes.