Ecology, Environment and Conservation Paper

EFFECT OF PHYSIOLOGICAL FACTORS OF EXPLANTS ON DEGREE OF BROWNING AND IN VITRO ESTABLISHMENT OF EXPLANTS IN CUSTARD APPLE (ANNONA SQUAMOSA L.) CV. BALANAGAR

R. K. Panchal, R. M. Patel and Pushpraj Singh

Abstract

The present investigation was carried out to study the effect of the position of node and size of explants on degree of browning and in vitro establishment of explants in custard apple (Annona squamosa L.) cv. Balanagar. Establishment medium used was MS + 0.5 mg/L 6-benzylaminopurine + 0.5 mg/L kinetin + 100 mg/l casein hydrolysate. Physiological factors studied were the position of node (5 levels) and size of explants (5 levels); types of explants viz. shoot tips and axillary buds explants. In case of size of explants, minimum browning intensity was seen at 2.0-2.5 cm length of explants. Thereafter, the intensity of browning was increased as increased the length of explants. However, at 1.5 cm length of explants reported comparatively more browning than 2.0 cm length of explants. Maximum establishment of explants (58.05%) was obtained in explants of 3rd node having 2.5 cm length, which was followed by 2.0 cm length (55.55%). Maximum length of shoots (1.10 cm) was observed in 3rd position of node at 2.5 cm length of explants followed by 2.0 cm (1.05 cm) and 1.5 cm (1.04 cm) length of explants at the same nodal position of explants. Overall, it is seen that 3rd position of nodal explants having the 2.5 cm length gave the best response for browning control besides higher establishment and growth of explants. The browning intensity was found comparatively less in axillary bud explants than shoot tip explants.