Androgenic ability and plant regeneration potential in some tomato varieties

Abstract

Aiming to evaluate the in vitro regeneration potential, five varieties of tomatoes (Solanum lycopersicum) were studied for their response in anther culture. Anther explants at an early stage of microspore development were inoculated onto three culture media. The first differentiation processes were recorded during the first three weeks of culture, in darkness. The statistical analysis of the data recorded during the anther culture showed significant differences between genotypes regarding their specific response to culture conditions and the significant influence of the initiation medium composition in triggering the differentiation processes. Under the tested conditions were induced: the embryogenic potential in three genotypes (ʻȘtefănești 22ʼ, ʻCostate 21ʼ and ʻChihlimbarʼ) and the indirect organogenesis in two genotypes (ʻArgeș 20ʼ and ʻCostate 21ʼ). Morphological characteristics of anther-derived plants from ʻArgeș 20ʼ variety, grown in greenhouse conditions (growth rate, features of leaf,  flower, and fruit), as well as analyses with nine SSR markers (banding patterns, the coefficient of genetic similarity, and the polymorphism information content) in DNA samples from each regenerant and the donor variety, provided clear evidence of the occurrence of spontaneous genetic variation during in vitro anther culture, and of the existence of somaclonal variation in regenerated plants. The amplified products obtained with SSR primers revealed a total number of scorable bands of 160 and a mean percentage of polymorphic bands of 21.09%. Two out of the nine tested primers, SSR63 and SLM6-7 proved to be efficient in detecting genetic differences not only among regenerants but also between them and the donor genotype.