Genetic analysis of anther and leaf disc culture in two clones of Solanum chacoense Bitt. and their reciprocal hybrids

Abstract

Two diploid clones of self-incompatible Solanum chacoense Bitt. with androgenetic ability were tested for anther and leaf disc culture response together with eight of their reciprocal F1 hybrids. Large differences were found among genotypes in frequency of anther induction as well as in the phase of plant regeneration. Anthers harvested in June showed a significantly higher percentage of response (17.5%) at the induction phase than those collected in July (13.8%) or August (12.7%). The lowest induction frequency was observed in May (7.3%). By contrast, plant regeneration from induced anthers did not vary during this time. Genotypic differences were also observed in leaf disc response. The two parental clones and two of their hybrids failed to produced any shoots. Among the remaining genotypes, two had only sporadic occurrence of shoot formation, two gave an intermediate response (15% and 24% of their discs carried shoots), whereas the discs of the two remaining genotypes responded well to culture (68% and 77%). The genetic analysis performed on the reciprocal hybrids revealed that a positive significant correlation existed between anther induction and leaf disc response (Spearman's r=0.82; p=0.01). This suggests that, under our conditions, these two aspects of tissue culture might share a common system of genetic control. Estimates of broad sense heritabilities, for leaf disc culture, 83% were obtained and the number of effective factors involved in the control of tissue culture response, indicated a relatively simple genetic control. Finally, considering the potentialities opened by the use of RFLP analysis, it might be possible to find probes that are linked with genes involved in tissue culture competence.