Chloroplast inheritance patterns in Actinidia hybrids determined by single stranded conformation polymorphism analysis.

The inheritance patterns of the chloroplast genomes of the Actinidia hybrids A. eriantha (male parent) × A. chinensis (female parent) and A. chinensis (male parent) x A. melanandra (female parent) were analyzed using single-strand conformation polymorphism (SSCP) analysis of the trnL-trnF and psbA-trnH intergenic spacers. This showed that the artificial hybrids between A. eriantha and A. chinensis all had the haplotype of their male parent. Alignment of the sequences of A. eriantha and A. chinensis revealed four substitutions and one insertion (GATTC) in trnL-trnF and two substitutions in psbA-trnH. In contrast, the haplotypes of the artificial hybrids between A. chinensis and A. melanandra had the same patterns as their female parent. Alignment of the entire region of A. chinensis and A. melanandra revealed 12 substitutions: 1 in trnL-trnF and 11 in psbA-trnH. However, no sequence variation in the trnL-trnF and psbA-trnH intergenic spacers was found. We have developed a simple screening method for detecting the inheritance patterns of Actinidia chloroplast DNA haplotypes using SSCP analysis of the trnL-trnF and psbA-trnH intergenic spacers. Our findings indicate that the inheritance of the chloroplast genome in Actinidia hybrids differs according to the species selected.