Screening diploid Solanum genotypes responsive to different anther cultureconditions and ploidy assessment of anther-derived roots and plantlets

Twenty-three diploid (2n=2x=24) potato clones were screened for response to four different anther culture media. Anther derived tissues (calli/embryos ) were obtained from seven of the clones in liquid culture media. Anther cu lture response of these seven clones was further quantified on five additio nal media Since clonal responses are specific to culture conditions (Tiaine n, 1992), the seven genotypes somewhat differed from each other in the magn itude of the response to each of the media. In agreement with Heberle-Bors (1985) a more realistic assessment of the responsiveness was possible when pollen counts per anther were used to express the yield of anther-derived m aterial. A relatively higher level of exogenous cytokinin (6-benzyladenine) to that of auxin (3-indoleacetic acid) proved to be favourable for the ind ucton of calli/embryos, Use of a semi-solid medium saved space and was conv enient for culture observations therefore it was found more conducive for t he genotypic screening, Anther derived tissues that regenerated to produce root tissue and/or plantlets were further multiplied on a root culture medi um and a plantlet medium. Liquid culture conditions on orbital shakers were conducive for the growth of root explants, Anther derived material (roots and plantlets) originating from clone 9507-04 revealed differences in growt h vigor. Flow cytometric estimation of ploidy in regenerated roots and plan tlets, revealed that clone 9507-04 produced 44% monoploid roots and 77% mon oploid plantlets, Seventy-three percent anther-derived plantlets from clone 6028-02 were monoploids.