Use of 2n pollen in generating interspecific derivatives of groundnut

Abstract

A cytological analysis was conducted for interspecific hybrids obtained from the cross between Arachis hypogaea and A. hoehnei, A, cardenasii, A. chiquitana, A. kretschmeri and A. glabrata, and from A. diogoi × A. glabrata and A. duranensis × A. glabrata. Dyads, triads and tetrads were observed in the F1 hybrids. Detailed cytological analysis revealed the restitution of second division, which indicated that the first meiotic division was normal, but the cytokinesis in the second division was impaired, resulting in the formation of dyads and triads. The formation of 2n pollen in F1 hybrids from A. hypogaea × A. chiquitana, A. hypogaea × A. kretschmeri and A. duranensis × A. glabrata was observed. The 2n pollen from A. hypogaea × A. chiquitana or A. hypogaea × A. kretschmeri was used to develop tetraploid hybrids with A. hypogaea without going through the backcrossing of hexaploids. Crosses using triploid pollen (A. hypogaea × A. cardenasii) gave rise to a few pegs and pods, further confirming that some of the triploid pollen were fertile. Reciprocal crosses using the triploid (A. hypogaea × A. cardenasii) as the female parent and A. hypogaea as the pollen donor resulted in 6% peg formation and 7 pods. Tetraploid hybrids were obtained from A. hypogaea × A. cardenasii as the female parent and A. hypogaea as the pollen donor