Creation of Early-maturing DH Lines of Brassica campestris var. purpuraria through Microspore Culture Technique

In order to obtain early maturing double haploid（DH） plants and accelerate the breeding process of early maturing Brassica campestris var. purpuraria. This study used 15 early maturing Brassica campestris var. purpuraria varieties as test materials for microspore culture, observing the development process of microspores and identifying ploidy of regenerated plants. The results indicated that when the petal/anther（P/A） length ratio was between 0.6 and 0.8, approximately 72% to 78% of the microspores of red amaranth were in the uninucleate stage at the periphery; A total of 6 genotypes of red amaranth were able to produce embryos, with gy21-55 exhibiting the highest embryogenesis rate, the average embryogenesis rate was 14.3 embryos per bud; The cotyledonary embryos were selected for plant regeneration, and the plantlet conversion rate exceeded 90%;Flow cytometry was utilized to determine the ploidy level of the regenerated plants, with an average natural doubling rate of 76.8%. Gy21-40 and Gy21-55 exhibited early maturity traits, and the DH plants obtained from them showed a respective advancement of 5 days and 8 days in bolting compared to the control plants.