Showing papers by "Andy Ganapathi published in 2003"

In vitro organogenesis and plant formation in Vigna radiata (L.) Wilczek

Abstract: In vitro organogenesis was achieved from calluses derived from cotyledon and hypocotyl explants of Vigna radiata on MS medium. Organogenic calluses were induced from both cotyledon and hypocotyl explants excised from 3-day-old seedlings on MS medium containing NAA (1.07 μm and BA (2.22 μm) and 2,4-D (0.90 μm) and BA (2.22 μm) combinations respectively. Regeneration of adventitious shoots from cotyledon derived callus was achieved when they were cultured on MS medium supplemented with NAA (1.07 μm), BA (8.88 μm) and 10% coconut water. Hypocotyl derived calluses produced adventitious shoots when cultured on MS medium fortified with BA (6.66 μm), TDZ (2.5 μm) and 10% coconut water. Addition of GA at 1.73 μm favored maximum 3 elongation of shoots. Regenerated shoots produced prominent roots when transferred to half strength MS medium supplemented with 4.90 μm IBA. Rooted plantlets, thus developed were hardened and successfully established in field. Among the different carbohydrates and media tested, 87.64 μm sucrose and MS+B5 medium proved best for maximum production of shoots. This protocol produced an average of seven plants per hypocotyl derived callus and 15 plants per cotyledon derived callus over a period of 3 months.

In vitro propagation of Acacia sinuata (Lour.) Merr. from nodal segments of a 10-year-old tree

Abstract: An in vitro propagation protocol has been developed using nodal explants from a mature ‘elite’ tree of Acacia sinuata. Tissue browning was circumvented by soaking surface-disinfected explants in a solution of antioxidant (238 μM citric acid). Maximum shoot proliferation (75.2%) was achieved from nodal explants collected during the December to March season in Murashige and Skoog's (MS) medium supplemented with 8.9μM 6-benzyladenine (BA), 2.5μM thidiazuron (TDZ), and 135.7μM adenine sulfate (AS) at the end of the first transfer following initial culture (60 d after inoculation). Gibberellic acid (GA3) at 1.8 μM promoted shoot elongation. The number of shoots was increased by (1) repeated subculturing of nodal explants on fresh medium with the same composition, and (2) using microcuttings from in vitro-regenerated shoots on MS medium containing 6.6 μM BA where each node produced four shoots. When transferred to half-strength MS medium augmented with 7.4 μM indolebutyric acid (IBA) in vitro-regenerated shoots produced prominent roots. Rooted plants were hardened and successfully established in soil. This protocol yielded an average of 100 plants per nodal explant over a period of 3 mo.

In Vitro Organogenesis

Abstract: Legumes are important sources of proteins for the growing population in many developing countries of the world. Their production is limited due to the crop’s susceptibility to fungal, bacterial and viral diseases, insect pests and besides many other undesirable agronomic traits. Genetic improvement of legumes by classical breeding has met with limited success due to the lack of genetic variability within the germplasm. Strategies for increasing and stabilizing the production of legume crops depend on the development of varieties resistant to diseases, pests and with other desirable agronomic traits. Recent biotechnological advances have offered the opportunity to develop new germplasms. The development of such technology largely depends on the availability of efficient regeneration protocols. In the present review, regeneration via organogenesis in legumes is described. The advantages and limitations of this technique along with directions for future research are discussed.

High-frequency plant regeneration from cotyledon callus of Acacia sinuata (Lour.) Merr

Abstract: A new reliable protocol for the induction of adventitious shoots and plant regenertion from cotyledon-derived callus of Acacia sinuata has been developed. Calluses were induced from cotyledon explants on Murashige and Skoog (MS) medium containing 3% sucrose, 0.8% agar or 0.15% phytagel, 8.1 μM α-naphthaleneacetic acid, and 2.2 μM 6-benzylaminopurine (BA). High-frequency regeneration of adventitious buds from callus was achieved when cultured on half-strength MS medium supplemented with 10% coconut water, 13.3 μM BA, and 2.5 μM zeatin. Histological studies revealed that the regenerated shoots originated from the callus. Among the various carbohydrates tested, sucrose at 87.6 mM was optimum for shoot-bud induction. Addition of 1.7 μM gibberellic acid along with 4.4 μM favored shoot elongation. In vitro-raised shoots produced prominent roots when transferred to half-strength MS medium supplemented with 7.4 μM indole-3-butyric acid. Rooted plants, thus developed, were hardened and successfully established in soil (45%). This protocol yielded an average of 40 plantlets per cotyledon explant over a period of 3 mo.