Shoot organogenesis and plant regeneration of Adesmia bicolor and A. latifolia (Leguminosae)

MARÍA LAURA VIDOZ; KENNETH HAYS QUESENBERRY

Indianapolis. Indiana. EEUU

Congreso; American Society of Agronomy- Crop Science Society of America- Soil Science Society of America- 2006 International Annual Meetings; 2006

American Society of Agronomy- Crop Science Society of America- Soil Science Society of America

The genus Adesmia comprises approximately 230 species native to South America, most of which have good forage quality and exhibit winter growth. The objective of this research was to evaluate the effect of different basal media on the in vitro response of several genotypes of A. bicolor and A. latifolia. Seven genotypes of A. bicolor and sixteen of A. latifolia were evaluated. Seeds were scarified with 98% H2SO4 for 5 minutes, rinsed with running tap water for 10 minutes, surface disinfected with 70% ethanol for 30 seconds followed by 6 g L-1 NaOCl plus one drop Tween 20® for 10 minutes, and rinsed 3x with sterile distilled water. Seed germination was achieved in half strength Murashige and Skoog (1962) basal medium (MS), with 15 g L-1 sucrose. Explants consisted of leaflets excised from immature leaves (approximately 50% expansion). Three basal medium were evaluated: MS (Murashige & Skooge, 1962), B5 (Gamborg et al., 1968) or L2 (Collins & Phillips, 1982) and were solidified with 7 g L-1 of agar. All basal media contained 1mg/L Thidiazuron as the only growth regulator. Ten explants were used per treatment, and experiments were repeated twice. Cultures were incubated at 25±2 ºC, with 14 hour photoperiod. Three weeks after initiation of cultures, adventitious bud formation begun in 1/7 of the genotypes of A. bicolor, and in 11/16 of A. latifolia genotypes.  All the responsive genotypes produced buds in MS, whereas only 6/12 and 8/12 did so in B5 and L2, respectively. Five genotypes were capable of regenerating adventitious buds in the three basal medium. After 60 days of culture initiation, buds were transferred to MS + 0.01 mg/L benzyladenine + 0.01mg/L indolebutyric acid, where they elongated and rooted. Plants were placed onto MS without PGRs for further development. Regenerated plants were successfully acclimatized ex vitro.