Hybrids in the Genus Arachis Between Sections Erectoides and Arachis1

Abstract

The objective of this study was to determine whether diploid members of section Arachis could potentially be used as bridges between section Erectoides Krap. et. Greg. nom. nud. and A. hypogaea. Two diploid (2n = 20) taxa of section Erectoides and their F1 and F2C1 hybrids were evaluated. The female parent, A. rigonii Krap. et Greg. (PI 262142, collection no. GKP 10034), and male parent, A. sp. (PI 262278, collection no. GKP 9841) had perfect bivalent formation, but the F1 did not produce enough flowers to cytologically examine. The F2C1 averaged 2.76 univalents, 18.48 bivalents, 0.04 trivalents, and 0.04 quadrivalents per pollen mother cell and pairing of chromosomes between the two section Erectoides species is believed to be minimal. Hybrids between the F2C1 and the diploid section Arachis species A. stenosperma Greg. et Greg, nom. nud. (PI 338280, collection no. HLK 410) and A. duranensis Krap. et Greg. nom. nud. (PI 219823, collection no. K 7988) were studied. Multivalents were observed at a low frequency. Members of sections Erectoides and Arachis may have a common genome.The results indicate that gene transfer from section Erectoides species into the cultivated peanut seems possible by using diploid members of section Arachis as bridge species. Early metaphase I microsporocytes with an unreduced chromosome number were observed in three hybrids. Two fruits were recovered from intersectional colchicine‐treated hybrids, but the seeds were inviable. Future success in restoring fertility may depend on propagating large numbers of colchicine‐treated cuttings.