Anther culture through direct embryogenesis in a genetically diverse range of potato (Solanum) species and their interspecific and intergeneric hybrids

Abstract

The present anther culture procedure has been utilized successfully for a genetically diverse range of potato material including commercial varieties of cultivated potato (Solanum tuberosum ssp. tuberosum), its related wild species and various hybrids having wild Solanum spp. germplasm. Previously, cultivated potato has been described as a recalcitrant crop plant with regard to androgenesis, and progress in haploid production through direct embryogenesis using anther culture has been considerably limited. Therefore parthenogenesis through pollination with selected clones of S. phureja is still widely utilized for haploid production in potato. However, wild characteristics derived from the S. phureja pollinator and aneusomatic genomic constitutions in the resultant haploid lines are common when parthenogenesis (gynogenic pathway) is carried out for practical haploid production in potato. Isolated microspore culture in potato has yet to provide results for plant production. Therefore, in vitro androgenesis through direct embryogenesis in anther culture, the method described in the current article, is suggested for haploid production in potato and its relatives. The present anther culture protocol has been conducted on a genetically diverse range of Solanum spp. material. The method was originally introduced for dihaploid (2n=2x=24) production from tetraploid (2n=4x=48) varieties of cultivated potato (Rokka et al., 1996), but since then it has also been utilized for: tetraploid breeding material with wild potato germplasm; dihaploid lines of cultivated potato; S. acaule ssp. acaule wild potato species (Rokka et al., 1998); interspecific hybrids between A genome potato species (S. tuberosum and S. acaule); tetraploid and hexaploid interspecific hybrids between A and E genome species [S. tuberosum x S. brevidens hybrids, Rokka et al. (1995); S. tuberosum x S. etuberosum hybrids, V-M. Rokka, R. Thieme and T. Gavrilenko, unpublished results]; and intergeneric tomato (Lycopersicon esculentum + Solanum etuberosum) somatic hybrids (Gavrilenko et al., 2001).