Comparative studies on the competence of axillary shoot regeneration on unsliced and longitudinally sliced cotyledon nodes of Vigna unguiculata

Vigna unguiculata is an important food legume crop in the semiarid tropics. It suff ers from a host of\udagricultural constraints including damage due to diseases and pests. Judicious application of biotechnological methods\udcan lead to considerable improvement in this important crop. Shoot regeneration from unsliced and longitudinally sliced\udcotyledon node explants obtained from 3-day-old to 5-day-old seedlings grown in vitro was achieved on Murashige and\udSkoog (MS) medium containing 1.11, 2.22, 3.33, and 4.44 μM benzylaminopurine (BA) supplemented with 1.0 mg/L\udpolyvinylpyrrolidone and 500 mg/L bacteriostatic Augmentin. Callus induction was recorded in all culture media on\udboth explants. Th e shoot regeneration frequency (%) of longitudinally sliced cotyledon node explants was 2-fold to\ud3-fold higher than that of unsliced cotyledon node explants. A maximum number of 9.92 shoots per longitudinally sliced\udcotyledon node explant was recorded on MS medium containing 3.33 μM BA. Each increase in the BA concentration of\udthe culture medium proportionally decreased the mean shoot length on both explants. Maximum mean shoot lengths\udof 2.80 cm on unsliced cotyledon nodes and 3.04 cm on longitudinally sliced cotyledon node explant were recorded\udon MS medium containing 1.11 μM BA. Regenerated shoots were rooted on MS rooting medium containing 2.45 μM\udindole-3-butyric acid. In vitro regenerated plants were acclimatised at room temperature in growth rooms, where they\udproduced viable seeds