Transference of multiple resistance to peanut through the development of cross-compatible complex hybrids of wild arachis

Abstract

Peanut (Arachis hypogaea L.) is a tetraploid species with an A and B genome, while the majority of wild Arachis species are diploid with distinct genomes. In pre-breeding programs, one way to introgress interesting wild genes into peanut is by producing amphidiploids. This study aimed at the hybridization between distinct amphidiploids and their characterization, to combine high crossability with peanut, observed in some amphidiploids, with high pest and disease resistances observed in others. These new hybrids were called complex hybrids. Four amphidiploids previ-ously obtained were crossed at four different combinations, and the derived complex hybrids were crossed with four peanut cultivars. Morphological, reproductive, chromosome complement, molecular markers for hybrid identifica-tion, phytopatological, and entomological characterizations were performed on the complex hybrids. All cross combinations resulted in complex hybrids. One complete complement of each diploid progenitor was confirmed in each hybrid. Plants of six distinct hybrid combinations were obtained between the complex hybrids and peanut. Based on morphological characterization, differences among progenies from distinct cross combinations were observed. Complex hybrids were considered more resistant to all diseases and pests than peanut cultivars. The simultaneous introgression of genes from four wild Arachis species into peanut was possible through the development of complex hybrids.