Protocol optimization for <i>in vitro</i> shoot multiplication of Jackfruit (<i>Artocarpus heterophyllus</i> L.)

Abstract

Jackfruit (Artocarpus heterophyllus L.) is a cross pollinated fruit tree valued mainly for its fruit and timber wood. Although the crop has been introduced to Ethiopia and adapted well to the Jimma area, its potential for production has not been exploited due to the absence of an efficient method for large scale propagation. Micropropagation is a method for production of large number of genetically uniform planting materials with desired characteristics. The present study was initiated to determine the optimum concentration and combination of benzylaminopurine (BAP) and naphthaleneacetic acid (NAA) for in vitro shoot multiplication. For this study, shoot tips were used as an explant source. The shoot tips from mature trees were sterilized with 70% ethanol and HgCl₂ before culturing on Murashige and Skoog (MS) medium supplemented with different combinations of BAP and NAA. The results show that, the combination of BAP and NAA resulted in significant (P<0.01) differences for shoot number, shoot length and leaf number, whereby 2 mg/L BAP alone was found to be the best with a mean shoot number of 5.12 and length of 0.89 cm. The optimized protocol could be used as a baseline for further studies on in vitro propagation of jackfruit.

Key words: Artocarpus heterophyllus L., mercuric chloride, auxiliary shoot.