Improved approaches in wheat × maize crossing for wheat doubled haploid production

Abstract

Wheat x maize crossing is a fast but rather expensive method for doubled haploid production in hexaploid winter wheat. There is an ultimate need for improved efficiency of the method at lower cost. The effect of hormonal treatment and crossing technique on wheat haploid production efficiency were studied. The variation in 2,4-D concentration within the studied range (20–100 mg l–1) had no influence on total efficiency of wheat x maize crosses, while addition of 100 mgl–1 AgNO3 to 50 mgl–1 2,4-D solution enhanced embryo formation in wheat x maize crosses from 16.1 to 20.3% (embryos / pollinated florets). The efficiency of wheat x maize crosses was also enhanced by simplifying the crossing technique. Wheat floret emasculation and internode 2,4-D injection was substitute by direct pollination prior to anthesis and subsequent dipping of spikes into 2,4-D solution which resulted in considerable savings of time and labour required. Keywords: wheat × maize crossing, doubled haploid, 2,4-dichlorphenoxyacetic acid (2,4-D)