RAPD markers for confirmation of somatic hybrids in the dihaploid breeding of potato (Solanum tuberosum L.)

Molecular diversity in the genus Nicotiana as revealed by randomly amplified polymorphic DNA

The genus Nicotiana consists of 64 recognized species of which, only two species, tabacum and rustica are cultivated extensively. Wild Nicotiana species are storehouses of genes for several diseases and pests, besides genes for several important phytochemicals and quality traits, which are not present in cultivated varieties. Randomly amplified polymorphic DNA (RAPD) analysis was used to determine the degree of genetic variation in the genus Nicotiana and to develop species specific markers. Twenty two species and two interspecific hybrids were analyzed by using 18 random decamer primers. Genetic polymorphism abounds among the wild species of genus Nicotiana (99.5 %) as evidenced by the high degree of polymorphism in RAPD profiles. The pairwise similarity measures in the species of subgenus Rustica was 0.252 whereas in the subgenus Tabacum was 0.189, suggesting that there was significant diversity among the species of these subgenera. In the species of subgenus Petunioides, the range of pairwise similarity measures was 0.128 to 0.941. The clustering pattern coincided with the traditional classification of Nicotiana species. All the primers generated specific bands in the various species. Thirty six species-specific markers identified in the present study will be useful in interspecific breeding programs.

Genetic and alkaloid analysis of Papaver species and their F1 hybrid by RAPD, HPLC and ELISA

Total DNA was extracted from the leaves of a F1 hybrid and its parents, Papaver bracteatum Lindle and P. pseudo-orientale Medw. Analysis of random-amplified polymorphic DNA (RAPD) using ten arbitrary oligonucleotide 10-mers, showed that F1 hybrid was confirmed to be genetically intermediate of both parental plants compared with the genetic distance between F1 hybrid and individual parents. Furthermore, the comparison of the band patterns between a F1 hybrid, P. bracteatum and P. pseudo-orientale clearly showed that part of the bands of both parents were induced into a F1 hybrid. The content of thebaine was determined by HPLC and ELISA used anti-thebaine monoclonal antibody.

Micropropagation ofPanax notoginseng by somatic embryogenesis and RAPD analysis of regenerated plantlets

Somatic embryogenesis was induced in callus tissues derived from young flower buds ofPanax notoginseng via callus within 18 weeks of culture. The mature somatic embryos were germinated on half-strength Murashige and Skoog's (MS) medium supplemented with gibberellic acid A₃(GA) and 6-benzyladenine (BA). The most suitable medium for optimal root formation proved to be MS medium supplemented with 1-naphthaleneacetic acid (NAA). Total DNA was extracted from the leaves of the regenerated plantlets ofP. notoginseng. Analysis of random-amplified polymorphic DNA (RAPD) using 21 arbitrary oligonucleotide 10-mers, showed the genetic homogeneity ofP. notoginseng. The amplification products were monomorphic for all of the plantlets ofP. notoginseng regenerated by embryogenesis, suggesting that somatic embryogenesis can be used for clonal micropropagation of this plant.