Hide/Show Apps

Optimization of a regeneration and transformation system for lentil (lens culinaris M., cv. Sultan-I) cotyledonary petioles and epicotyls

Bayraç, Abdullah Tahir
In this study, optimization of a transformation and regeneration system via indirect organogenesis in cotyledonary petiole tissue of lentil (Lens culinaris Medik.) was investigated. Eight different medium types differing in their plant growth regulator compositions were employed to examine the callus induction potency of cotyledonary petiole. Except two, all other tested medium yielded more than 80% callus induction. Nine different medium types were studied to test the potencies of callus structures for shoot induction. Only the callus induced in medium H (1 mg/L Zeatin riboside + 1 mg/L Naphthalane acetic acid) yielded shoots at 8 to 40 % frequency. The most responsive medium was MS basal medium with no growth regulators. Also five and three different medium types were employed to examine callus induction potency of epicotyl tissues respectively. Each medium type yielded 90% callus induction. Only the callus induced in medium H yielded shoots At 6 to 26% frequency. Preliminary studies were carried out for somatic embryogenesis in cotyledonary petiole. Effects of salicylic acid on somatic embryogenesis were also investigated. Salicylic acid at 200æM was found to enhance the percentage of somatic embryos by 25 % and reduce the necrosis 24 %. However none of the globular and heart shape embryos were able to regenerate. Transient GUS expression efficiencies of roots, shoot tips, and cotyledonary petioles were tested after Agrobacterium-mediated transformation. Transformation frequencies were 26, 74, and 38 % for cotyledonary petiole, shoot tips, and roots respectively.