Albinism does not correlate with biparental inheritance of plastid DNA in interspecific hybrids in Cicer species

Abstract

Cultivated chickpea (Cicer arietinum) was crossed with its wild relatives from the genus Cicer to transfer favorable genes from the wider gene pool into the cultivar. Post-hybridization barriers led to yellowing and subsequent senescence from as early as 5 days after fertilization, however, the ovules of hybrid embryos could be rescued in vitro. Hybrids were classified as green, partially green or albino. The hybrid status of regenerated plantlets in vitro was confirmed by amplification of nuclear DNA markers. To check whether chloroplast development correlated with plastid DNA inheritance in these crosses, primers were designed using conserved plastid gene sequences from wild and cultivated species. All three possible plastid inheritance patterns were observed: paternal, maternal and biparental. This is the first report of biparental inheritance of plastid DNA in Cicer. No correlation was observed between parental origin of the plastid genome and degree of albinism, indicating that chloroplast development in hybrid genotypes was mostly influenced by nuclear factors.