Short communication. Micropropagation of two Pakistani soybean (Glycine max L.) cultivars from cotyledonary nodes

Soybean is an important oilseed crop throughout the world and there are continuous efforts to improve it through various techniques from field to laboratory. Although soybean has been grown in Pakistan since a long period, there are no or limited factors involving its improvement through biotechnological techniques in this country. This study aimed to optimize a regeneration protocol for two soybean cultivars, NARC-4 and NARC-7, using cotyledonary nodes as explant. Cultivar NARC-4 showed higher percentage of regeneration (88%) and mean number of shoots per explant (7.3 shoot per explant) compared to cv. NARC-7 with maximum frequency of 82% shoot regeneration and maximum mean number of 6.4 shoots per explant. However, variants of cyotkinins in the media had variable effects on regeneration and shoot length. Generally 6-benzylamino purine was better compared to zeatin riboside and kinetin. The results showed that half cotyledon could be effectively used as explant for direct micropropagation in soybean. The results could also be exploited positively for Agrobacterium-mediated genetic transformation.