PTC Variation in the Induction of Haploidy and Polyembryony in Spring Wheat through Wheat × Maize System

Five varieties of wheat such as Rawal, Chyria 3, Shatabdi, Sonalika and Kanchan were crossed with a maize variety Popcorn. Fertilization of wheat egg and formation and development of haploid embryos were facilitated by two post pollination treatments which include application of (i) 100 ppm 2,4-D and (ii) 100 ppm 2,4-D + 120 ppm AgNO3. The haploid embryos were cultured on MS and finally regenerated haploid plants. Significant variations were observed among the wheat varieties for the development of caryopsis, formation of embryos and regeneration of haploid plants. The varieties Chyria 3 and Sonalika proved better for setting of caryopsis, production of embryos and regeneration of haploids. They yielded 8.04 and 5.03 per cent haploid plants over the pollinated florets, respectively. There were no significant variations by the application of 2,4-D and 2,4-D + AgNO3 for the formation of haploid embryos and regeneration of plants from them. Some caryopsis contained more than one embryos indicating the occurrence of polyembryo in wheat when crossed with maize. The highest number of polyembryo was obtained in the variety Chyria 3 followed by Shatabdi and Sonalika.