Production and characterization of haploids derived from somatic hybrids between Solanum brevidens and S-tuberosum through anther culture

Somatic hybrids between dihaploid (2n = 2x = 24) cultivated potato (Solanum tuberosum L.) and diploid (2n = 2x = 24), virus resistant wild potato specie S. brevidens Phil., were tested for their feasibility for anther culture, A total of 17 shoots regenerated by embryogenesis from anthers of the hybrids. Five regenerants survived and were grown in vitro and in the greenhouse. The haploids were morphologically intermediate between S. brevidens and S. tuberosum. They were analysed for S. brevidens specific and S. tuberosum specific RAPD markers using four primers, and were found to contain the S, brevidens specific DNA markers and most of the S. tuberosum specific markers. The chromosome numbers of the haploids ranged from 34 to 36, According to flow cytometric analysis, the nuclear DNA contents of the haploids (2C = 2.15-2.30 pg) were approximately half of the hexaploid somatic hybrids (2C = 4.47-4.53 pg), The somatic hybrids were identified as chimeric (hypohexaploids), whereas the haploids derived from them using anther culture were all triploids according to flow cytometry. The haploids were extremely resistant to potato leaf roll virus.