Certain characteristics of rhyzogenesis in Lycopersicon esculentum Mill., Lycopersicon peruvianum var. dentatum Dun. and their cybrids
Aims. Capability for rooting of the peruvian and cultivated parental forms of the tomatoes (Lycopersicon peruvianum var. dentatum Dun. and Lycopersicon esculentum Mill.) and their cybrids with reciprocal plastom-genome organization as well as with back transferred chloroplasts was investigated. Methods. Shoots of the three different age and order groups of the nine tomato genotypes were grown on MS/2 medium with and without -naphtylacetic acid and their capability to multiple or single rhizogenesis estimated. Validity of the results obtained was calculated by variance analysis. Results. Among 3888 shoots only 2.1% were uncapable for rooting. One must point out that majority of such shoots was revealed when studying spontaneous rhizogenesis. Multiple regeneration of rootlets was encountered 1.8–4 times often in induced rhizogenesis than single one whereas in spontaneous rhizogenesis single rootlets formation encountered 1.7–4 times often compared to multiple one. In general regeneration of rootlets continues for six-nine days in induced rhizogenesis whereas in spontaneous rhizogenesis it exceeded 10 and even 20 days. Conclusions. Diversity of the two related genotypes (Quedlinburger Frühe Liebe і Frühe Liebe cultivars) was supported based on their ability for rooting as well as for four peruvian tomato cybrids clones with backward plastom transferred. Low ability for rooting of 1C clone of the cultivated tomato cybrid serves one more evidence for incompatibility of L. peruvianum var. dentatum plastom and L. esculentum nuclear genome. Both positive and negative correlation of rooting velocity was shown for clone B1A of peruvian tomato cybrid compared with parental species L. peruvianum var. dentatum what can evidence that rhizogenesis is controlled not only by nuclear genome but plastom as well.
Key words: Lycopersicon esculentum Mill., Lycopersicon peruvianum var. dentatum Dun., cytoplasmic hybrids, rhizogenesis, variance analysis.