Cytological Analysis and Fertility of Solanum commersonii Dun. × Solanum gourlayi Haw. Triploid Hybrids

Abstract

Meiotic analysis, pairing affinity and fertility studies were carried out in Solanum commersonii Dun. (cmm, 2n=2x=24) by Solanum gourlayi Haw. (grl, 2n=2x=24) triploid hybrids, obtained through the functioning of 2n eggs of cmm. Mean arm pairing frequency (“C”) and relative affinity (“X”) were calculated according to Alonso and Kimber (1981). The “C” value was high but the “X” value was intermediate. Pollen stainability for three triploid hybrids was 31.7, 29.5 and 2.5 respectively. Crosses between the cmm×grl triploids, used as females, and various species of Solanum with different ploidy were performed. Hybrids with 24 to 31 chromosomes were obtained from these crosses. The results of this study give and indication that the cmm and grl genomes are highly homologous. Therefore a high degree of gene exchange between the genomes of these species is expected to occurr in meiosis. The feasibility of utilizing grl as a “bridge” species, for transfering important genes of cmm to the cultivated potato, Solanum tuberosum L. are discussed. © 1992, Japan Mendel Society, International Society of Cytology. All rights reserved.