The application of n-butanol improves embryo and green plant production in anther culture of Australian wheat (Triticum aestivum L.) genotypes

The objective of this study was to improve the production from anther culture of embryos and green plants in Australian spring wheat genotypes by testing new treatments such as n-butanol, as well as other protocol modifications. To date, the use of n-butanol to enhance embryogenesis has only been tested in two European wheat cultivars; this is the first study which demonstrates its application across a range of breeding crosses. A5-h treatment using 0.1 or 0.2% (v/v) n-butanol following anther pretreatment on a solid mannitol medium significantly improved the production of embryos, green plants and doubled haploids in a range of Australian wheat crosses and varieties. Green plant production increased between 3- and 6-fold in the crosses Yitpi/2*Bumper, Tammarin Rock/2*Bumper and Tammarin Rock/2*Magenta. The addition of calcium (Ca) and macronutrients to the mannitol pretreatment medium also significantly improved the number of embryos and green plants in varieties and crosses, but only when used in combination with n-butanol treatment. A factorial experiment with four varieties and two treatments (n-butanol and Ca/macronutrients) revealed significant interactions between treatments and genotype. In three of the four varieties, the application of n-butanol resulted in significant increases in embryos and green plants with either pretreatment medium although the best results were obtained with Ca and macronutrients in the pretreatment medium, with 200, 193 and 52 green plants per 100 anthers obtained for Bumper, Gladius and Magenta, respectively. In the variety Fortune however, n-butanol treatment did not improve embryo or green plant production unless it was combined with Ca and macronutrients in the pretreatment medium and then there were dramatic improvements; from 0 to 27 green plants per 100 anthers.