Haploid induction through microspore embryogenesis in Bell pepper genotypes

Abstract Classical breeding has been adopted to evaluate and breed pepper cultivars across different parts of the world. However, multiple generations are required for screening, development of lines, evaluation, recognition and crossing for getting highly homozygous lines. In vitro microspore culture is the fastest approach to produce homozygous lines within a single generation. In the present study, a successful protocol for microspore embryogenesis from pepper hybrids Orobelle and Bomby was developed. During the present study, cold pretreatment of buds at 4°C for 4 days gave early and successful embryo formation from both the genotypes. MS medium containing 4mg/L NAA and 1mg/L BAP, 0.25% activated charcoal, 2.6 g/L gelrite, 30 g/L sucrose and 15 mg/L silver nitrate gave the highest efficiency of embryo formation (1.85% and 1.46%) in Orobelle and Bomby, respectively. Half strength MS medium fortified with 2% sucrose and 0.1 mg/L 6-benzylaminopurine (BA), solidified with 0.6% plant agar resulted in successful plant regeneration from embryos. Chromosomal status of the microspore derived plantlets was analyzed using flow cytometry. Haploid plants were characterized by reduced plant height, leaf length, leaf width and short internode length compared to seed derived diploid plants.