A comparative study of genotypic and environmental response to androgenesis in Nicotiana rustica.

A total of six genotypes of Nicotiana rustica comprising the two F1's (V2 × V12 and V1 × V5) and their parents were evaluated for their efficiency in haploid production. Excised immature flower buds with pollen at late uninucleate to early binucleate stage were pretreated for 21 days at 5 ° or 7 °C, or for 15 days at 9 °C before culturing on Nitsch's medium+ 0.1 mg/l NAA. The effects of genotype, pretreatment and their interaction were tested on anther response, anther productivity and days to first plantlet formation. Highly significant genotype X pretreatment interaction and differences between genotypes were observed for all three characters. Significant differences between pretreatments were observed for anther productivity only. The performance of V12 both in respect of anther productivity and response was highest whereas that of V5 was the lowest. Analysis of variance showed that a simple additive genetic model was not adequate to explain the above variation due to significant additive genetic and dominance interactions with the pretreatment.