Impact of genotype, plant growth regulators and activated charcoal on embryogenesis induction in microspore culture of pepper (Capsicum annuum L.)

The production of double haploids through androgenesis is used by breeders to produce homozygous lines in a single generation. Androgenesis can be achieved by isolated microspore culture, which, however, allows the production of embryogenesis with a very low efficiency. In order to improve the overall embryogenesis in pepper, we study the differences of microspore embryogenesis in different genotypes of pepper, and also document the effect of growth regulators in pretreatment media, and activated charcoal (AC) on embryogenesis induction. Fifty different pepper genotypes were evaluated, and the swollen rate of microspores from different genotypes varied from 3.11% to 29.56% with the mean value of 13.13%. Microspores from genotype '36' had the highest swollen rate, and the lowest swollen rate of microspores was observed in genotype '26'. It was concluded from the statistical results of L9 (33) orthogonal test that changes in the level of BA influenced the swollen rate of microspores more significantly, and the combination of 0 mg∙l− 1 6-benzyladenine (BA), 0.2 mg∙l− 1 α-naphthaleneacetic acid (NAA) and 0.5 mg∙l− 1 kinetinin (Kin) was best. AC at a concentration of 0.05% could act as a promoter of embryogenesis in the microspore culture of different pepper genotypes, while the more significant effect was observed with the low responsive genotypes.