Genetic analysis of in vitro growth and microtuber production in Solanum chacoense Bitt.

The genetics of in vitro growth and micro tuber production was examined by analyzing two self incompatible diploid (2n = 2x = 24) genotypes of S. chacoense and four of their reciprocal hybrids. The genotypes were screened for shoot length increase, rate of nodal multiplication, biomass accumulation, harvest indexand micro tuber production in in vitro. Significant differences were observed between genotypes for the characters measured except in number of nodes. The hybrids were better than the parents in biomass accumulation, harvest index and microtuber production and this indicates that these characters are controlled by either recessive alleles or by the epistatic interaction of the genes present singly in the parents. Estimates of the broad sense heritabilities and the number of genes or effective factors involved in the control of the trails were calculated. These estimates indicate that in vitro culture response in potato may be under simple genetic control. In addition, our studies indicate that in vitro tuberization and leaf disc culturability may share a common system of genetic control.