Determination of the response of different eggplant (Solanum melongena L.) genotypes to microspor culture

Microspore culture is a promising method for obtaining androgenic haploid and double haploid (DH) plants. The integration of microspore culture into eggplant breeding programs is very important for obtaining DH lines. Therefore, understanding the double haploid efficiency of different genetic resources in microspore culture in eggplant offers significant advantages in breeding studies. In this study, research was conducted on microspore culture in three different eggplant genotypes to determine the effect of genotype, one of the factors affecting microspore culture. For this purpose, anthers containing mostly vacuolar microspores and young double-nucleated pollen were first identified. Microspores were isolated from these anthers and subjected to a 3 day pre-treatment at 35°C in the dark to induce microspore embryogenesis. After pretreatment, the microspores were cultured in liquid NLN culture medium containing 2% sucrose, 0.5 mg/l naphthaleneacetic acid (NAA), and 0.5 mg/l 6-benzylaminopurine (BAP), adjusted to pH 5.9. They were kept in the dark at 25°C for one month. In these conditions, symmetric division and the formation of multinucleated structures were induced in the microspores of all three genotypes before callus formation, and callus formation occurred from the microspores at the end of one month. The total number of calli per Petri dish was recorded at the end of one month, and differences in response to microspore culture were observed among the genotypes. The average number of calli per Petri dish was 77 calli/Petri dish for the P1 genotype, 3.17 calli/Petri dish for the P2 genotype, and 52.08 calli/Petri dish for the P3 genotype. The conversion rate of callus obtained from microspore culture to plant was determined to be 14% in the P1 genotype and 7% in the P3 genotype; no regeneration was observed in the P2 genotype.