(288) Determination of Genetic Stability of In Vitro-derived Birch Plants

Abstract

Many woody plants, including some birch species, can be cloned using such in vitro techniques as pre-existing meristem culture, organogenesis, and embryogenesis. However, clonal fidelity of in vitro-derived plants is always a big concern because somaclonal variations may be induced during the entire in vitro process. To address this issue, we used random amplified polymorphic DNA (RAPD) markers to determine the genetic stability of in vitro-propagated plants of Betula platyphylla `Fargo'. Forty-two greenhouse-grown birch plants derived from a 10-year shoot tip culture (shoot-derived) and 42 in vitro plants regenerated from leaf tissues (regenerated) were randomly selected and evaluated for their genetic fidelity by RAPD. To date, 20 primers (C1-C20, Operon Technologies) were screened for all 84 plants. Only strong bands that are conservative were scored. Each primer generated a unique set of amplification products. Most of scoreable bands are ranged from 350 to 1800 bp. A total of 3696 fragments were amplified from 42 shoot-derived plants by all 20 primers with an average of 4.4 bands per primer, in which 6 primers produced polymorphic bands, indicating some genetic variations within shoot-derived plants. Nineteen out of 20 primers yielded 2772 clear and reproducible bands (an average of 3.47 per primer) from 42 regenerated plants with no significant variations being detected. Our preliminary results showed that in vitro regenerated plants are genetically uniform. However, a long-term tissue culture might result in a few genetic variations of birch species.