Effects of season, genotype, and nutrient medium on pepper anther culture and microspore development

Abstract

Pure lines of 3 pepper genotypes, including one tolerant (Alata 421) and one intolerant (Alata 195) to lower temperaturesand one intolerant (Alata 277A) to higher temperatures, together with one variety (Inan3363) tolerant to higher temperatures, wereselected from the pepper collection of Alata Horticultural Research Institute (Mersin, Turkey). Two different culture media (Medium1 - Murashige and Skoog [MS] + 4 mg L–1 naphthalene acetic acid [NAA] + 0.1 mg L–1 6-benzylaminopurine [BAP] + 0.25% activatedcharcoal + 8 g L–1 agar + 30 g L–1 sucrose + 15 mg L–1 silver nitrate [AgNO3]; Medium 2 - MS + 4 mg L–1 NAA + 0.5 mg L–1 BAP + 0.25%activated charcoal + 8 g L–1 agar + 30 g L–1 sucrose + 15 mg L–1 AgNO3) were used in this study. The anthers were cultured during differentperiods (12 months) in order to determine the highest embryo formation and haploid plant regeneration. In addition, all anthers weretaken before culturing and on the 1st, 2nd, 3rd, 4th, 8th, and 14th days of different months and were fixed with Carnoy’s solution.Development of microspores was observed cytologically using 4’-6-diamidino-2-phenylindole-2HCl (DAPI) and with acetocarminestain. At the end of the study, it was determined that both embryo formation and haploid plant development varied depending ongenotype and cultivation period. No significant differences in the number of embryos obtained were observed between the nutrientmedia. The highest percentage of haploid embryos was obtained from the Inan3363 variety, known to be tolerant to high temperature. Inaddition, the androgenic capacity of the Inan3363 variety increased to 65% during some anther culture cultivation periods. The antherscultured in September and July–August produced the highest yielding results compared with the other periods in terms of number ofhaploid embryos. Obtaining healthy and developed plants from the embryos was more successful in April, August, September, March,and May than in the other months. Studies on the microspores revealed that the high percentage of uninucleate phase at the beginningof the culture decreased rapidly in the following days.