title: Synthesis of Ogura male sterile rapeseed (Brassica napus L.) with cold tolerance by protoplast fusion and effects of atrazine resistance on seed yield.
abstract: Twenty-one cold-tolerant, male sterile Brassica napus somatic hybrids were produced by protoplast fusion. The fusion partners were a coldsensitive, Ogura cytoplasmic male sterile cauliflower inbred (B. oleracea var. botrytis inbred NY7642A) and a cold-tolerant, fertile canola-type B. rapa cv. Candle. Hybridity was confirmed by morphology, isozyme expression, flow cytometry, and DNA hybridization. Organellar analyses revealed a very strong bias for Brassica over Raphanus chloroplasts. Cold tolerance was confirmed by cold chamber studies and chloroplast DNA analyses. Good female fertility with 21.4 ± 3.1 seeds/pod was observed in the field using natural pollination vectors. Total seed yield was significantly greater for the atrazine-sensitive somatic hybrids produced in this study than for atrazine-resistant isolines.
authors.affiliation: Department of Plant Breeding and Biometry, Cornell University, 14853-1902, Ithaca, NY, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Heath
authors.forename: E D
authors.initials: ED
authors.lastname: Earle