Introgression of Cajanus platycarpus genome into cultivated pigeonpea, C. cajan

Abstract

SummaryCajanus platycarpus, an incompatible wild species from the tertiary gene pool of pigeonpea (C. cajan (L.) Millspaugh), has many desirable characteristics for the improvement of cultivated varieties. To necessitate such transfers, embryo rescue techniques were used to obtain F 1 hybrids. The F 1 hybrids were treated with colchicine to obtain tetraploid hybrids, that were selfed to obtain F 2 , F 3 and F 4 progenies. All of the hybrids and subsequent progenies had an intermediate morphology between the two parents. Backcrossing of the tetraploid hybrids with cultivated pigeonpea was not possible given embryo abortion, with smaller aborted embryos than those obtained in the F 0 parental cross.As a route of introgression, diploid F 1 hybrids were backcrossed with cultivated pigeonpea and BC 1 progeny obtained by in vitro culture of aborting embryos. BC 2 plants were obtained by normal, mature seed germination. Although embryo rescue techniques had to be used to obtain F 1 and BC 1 plants, it was possible to produce BC 2 and subsequent generations through direct mature seed. Every backcross to cultivated pigeonpea increased pollen fertility and the formation of mature seeds.

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…These studies also revealed that two of the wild relatives, C. cajanifolius and C. scarabaeoides, are closely related to pigeonpea. Cytological studies have also proved that C. cajanifolius is the progenitor species of C. cajan, as both species have similar karyotypes, and the hybrids produced from crossing the two species have normal meiosis with high pollen fertility (Pundir and Singh, 1985;Mallikarjuna et al, 2006). Pigeonpea (Cajanus cajan) is a short-lived perennial shrub that is cultivated as an annual grain legume crop in tropical and subtropical regions.…”

Mitochondrial SSRs and their utility in distinguishing wild species, CMS lines and maintainer lines in pigeonpea (Cajanus cajan L.)

“…van der Maesen (Saxena et al 2010a, b), A 7 CMS system from C. platycarpus (Benth.) van der Maesen (Mallikarjuna et al 2006) and most recently A 8 CMS system from C. reticulatus (Dryander) F. V. Muell. (Saxena 2013).…”

Conventional and Molecular Approaches towards Genetic Improvement in Pigeonpea for Insects Resistance

“…Some lines have shown a high level of resistance to pod borers, pod fly and bruchids under unprotected field conditions. Out of the 21 wild species in the tertiary gene pool of pigeonpea, only C. platycarpus has been utilized for improving insect resistance through inter-specific hybridization [66,67]. It (C. platycarpus) is a species of interest to pigeonpea breeders because it has various traits of interest [31].…”