Micropropagation and in vitro mutagenesis are reported in two local pineapple (Ananas
comosus (L.) Merr.) varieties, 'Smooth Cayenne' and 'Sugar Loaf. Multiple shoots developed
on Murashige and Skoog medium containing 3.5% sucrose, 3uM/l thiamine HC1, 3u.M/l
naphthalene acetic acid (NAA) and varying concentrations of 6-benzylaminopurine (BAP).
Shoot proliferation was best with 20 nM/1 BAP. Shoots were rooted on MS medium
supplemented with 1.5 uM/1 indole-3-butyric acid (IBA) and 0.75 uM/1 indole-3-acetic acid
(I A A). Radiosensitivity was determined by irradiating in vitro shoot tips with 15 to 120 Gy
gamma rays. The LD50 was found to be 45 Gy, and doses above 80 Gy were lethal to explants.
Projected methods are discussed to carry out mutation breeding for tolerance to drought and
heat