Culture media for the multiplication of wild Manihot species

Abstract

ABSTRACT The cassava propagation system is slow and favors disease transmission through successive generations. Micropropagation is an alternative to overcome the aforementioned limitations, besides allowing the generation of a larger number of pest- and pathogen-free plants. Therefore, the aim of the present study is to investigate the effect of culture media on the multiplication in vitro of five wild Manihot species. The experiment followed a completely randomized design, at factorial arrangement 5 (wild Manihot species) x 6 (culture media), with 11 repetitions. Explants consisted in nodal segments (91 cm long and one lateral bud) of species Manihot flabellifolia, M. tristis, M. caerulescens, M. chlorosticta and M. jacobinensis, which were extracted in vitro from the collection of wild cassava species. One segment was placed in each test tube added with 10 mL of MS media 0.01, 17N, 12A3, 4E, 8S and WPM, and kept for 90 days in growth room under 30 μmol m-2 s-1irradiance, temperature 27 ± 1 °C and 16h photoperiod. Variables plant height (cm), number of green leaves, number of senescent leaves, number of shoots, number of microcuttings, fresh and dry shoot mass, fresh and dry root mass (mg) and callus mass (mg) were analyzed. Our results showed that the culture medium 12A3 was not responsive to any of the species; however, if one takes into consideration variables plant height and number of microcuttings, this medium can possibly be used in the micropropagation of other wild species belonging to genus Manihot.