ENHANCED PRODUCTION OF DIHAPLOID LINES VIA ANTHER CULTURE OF TETRAPLOID POTATO (SOLANUM-TUBEROSUM L SSP TUBEROSUM) CLONES

A total of 1000 anther-derived plants was regenerated from tetraploid potato (Solanum tuberosum L.) genotypes. Capacity to undergo androgene sis was analysed in 41 potato cultivars and 7 clones grown either in t he greenhouse or in the field. Of the 48 genotypes, 33 produced embryo s and 23 regenerated shoots from embryos. Anther-derived plantlet prod uction was determined in genotypes 86110, Agria, Calgary, Escort, Heli os, Idole, JO0982, JO1432, Kainuun Musta, Kardal, KE48, Matilda, Nicol a, Petra, Pito, Rustica, Stirling, Torridon, Ute, Van Gogh, Vebeca, Ve nto and White Lady. The highest number of shoots (24 shoots/100 anther s) was obtained from cv. Calgary, when anthers were isolated from fiel d-grown donor plants. Incubating anthers at 28 C, rather than at 20 C or 24 C, enhanced embryo production in four genotypes tested. However, shoot production was improved only in cv. Pito cultured at 28 C. When anthers of cv. Petra were cultured at 28 C for four weeks, followed b y reduction of culture temperature to 24 C, a high rate of shoot produ ction was recorded (14 shoots/100 anthers). The ratio between dihaploi ds and tetraploids varied among the anther-derived plants of the diffe rent genotypes. The number of dihaploids was highest in potato clone J O1432 (100%) and in cv. Calgary (93%) and lowest in cvs. Pito (21%) an d Torridon (6%).