Improving the efficiency of haploid wheat production mediated by wide crossing

Abstract

[Summary]: This study examined several possible means of improving the wheat (Triticum aestivum L.) x maize (Zea mays L.) method for haploid production in Australian hard white spring wheat genotypes. Two wheat varieties were pollinated by each of five maize lines, giving an average of 22 embryos per 100 florets. One maize inbred gave a significantly lower haploid embryo yield. Embryos rescued 12 or 15 days post pollination had a significantly higher germination percentage (51 to 80%) than embryos rescued 9, 17, 19 or 21 days after pollination (6.4 to 31%). Embryos 12 to 15 days old were found to be large and easily rescued. Haploid wheat embryos germinated at equal frequencies on four commercial tissue culture media and germination frequency was not affected by differing levels of 6-benzylarninopurine (BAP). However, the rate at which haploid embryos germinated was found to be significantly affected by both the type of medium and the Cytokinin level. Haploid embryos germinated fastest on an MS based medium with 0.05 mg/L BAP.