In vitro Culture of Anthers and Stem Internodes of Lycopersicum peruvianum: Nuclear DNA Determination in Calli and Cytological Analysis of Regenerated Plants

Abstract

Summary In studies with Lycopersicum peruvianum , cytophotometric determinations of the DNA content in the isolated nuclei from calli of in vitro anther cultures of the genotypes S 1 S 3 and S 12 S 13 , and of stem internode cultures of the genotypes S 1 S 5 and S 4 S 5 , cultured on different media, were carried. The data indicated that the calli produced from anther cultures can differ in type, this being probably due to their differing origin. Two types of calli were observed: early-appearing, rapidly growing calli which contained cells with higher, and later-appearing, more slowly growing calli having cells with lower levels of ploidy. The latter type appears to have a greater possibility to have originated from microspores. From the calli of stem internode cultures from S 1 S 5 , in spite of no difference in the composition of nuclei detected with or without the presence of kinetin in the medium, more tetraploid plants were regenerated from calli cultured on medium containing kinetin. Prolonged culture of the calli resulted in regeneration of not only diploid plants, but also of tetraploid and octoploid plants. In the other genotype, S 4 S 5 , on media with and without kinetin, calli having nuclei with similar levels of ploidy, and regeneration of only diploid plants were observed.