<i>In Vitro</i> Clonal Propagation from Juvenile and Different Explant Types of Two Edible <i>Annonaceae</i> Species: <i>Annona muricata</i> L. and <i>Annona squamosa</i> L.

Abstract

Annona muricata L. and Annona squamosa L. are tropical species whose fleshy fruit is edible. They offer real possibilities for socio-economic use, particularly in the fields of medicine, nutrition, ecosystem conservation and the poverty alleviation. This study was set up to evaluate different methods of micropropagation from juvenile material for the regeneration of these species. Thus, MS medium supplemented with [BAP 2 mg&middot;L -1 ] i.e. M2 produced 2.87 newly formed shoots from the cotyledonary nodes of A. muricata . For the terminal apices of A. squamosa , it was MMS medium supplemented with [BAP 2 mg&middot;L -1 ] i.e. MM2 that was most conducive to new shoot formation (3.12). The addition of 0.1 and 0.2 mg&middot;L -1 of NAA in the M2 medium, made it possi ble to have the best elongations and average number of nodes for the new shoots from cotyledonary nodes of A. muricata (9.11 cm for 5.62 nodes). With A. squamosa , MM7 medium [MMS + BAP 1 mg&middot;L -1 + KIN 1 mg&middot;L -1 ] resulted in an average length of 9.05 cm with 5.62 nodes on average for the apical shoots. A 3-day rhizogenic induction period in the dark with [IBA 50 mg&middot;L -1 ] and 2 g&middot;L -1 of activated charcoal gave a rooting rate of 66.67% for shoots originating from the cotyledonary nodes of A. squamosa ; while with vitroplants from cotyledonary nodes of A. muricata , a better rooting rate (83.33%) was obtained following a 5-day rhizogenic induction. After 30 days of acclimatization, the survival rate reached 83.33% for plants from the tips of A. muricata , whereas for A. squamosa, it was plants grown from cotyledonary nodes that had the same survival rate.