Studies on <i style="">in vitro</i> propagation of Himalayan cedar (<i style="">Cedrus deodara</i>) using zygotic embryos and stem segments

Abstract

Adventitious bud formation was examined in zygotic embryos (decoated seeds) of <i style="">Cedrus deodara</i>, planted in the normal position, using four different media variously supplemented with or without plant growth regulators (PGRs). Following incubation for 7, 14, 21 and 28 days on PGR containing media, the embryos were transferred to respective PGR-free basal media. While embryo swelling was observed in all cases, normal germination was observed only in embryos cultured initially in PGR-free media. Best response, in terms of bud formation (93%), was observed in embryos first cultured on LP medium containing BA and Kinetin (1.0 <img src='/image/spc_char/micro.gif'> <i style="">M</i> each) for 28 days and then transferred to LP medium without any PGR. While the mean number of shoots formed per cultured embryo was also highest (34%) in this combination, these shoots eventually dried when excised and sub-cultured for further multiplication. Success was, however, obtained when the embryos were initially planted in an inverted position on LP medium containing 20.0 <img src='/image/spc_char/micro.gif'> <i style="">M</i> BA for 10 days, and then shifted, again in the inverted position, on the same medium without BA. Although the mean number of shoots formed was low (only 2.5 shoots per embryo), these could be multiplied and elongated. The microshoots (2.0-3.0 cm) thus obtained could be rooted (100%) using ½ strength, PGR-free, LP medium, hardened and established in pots. Besides excised embryos, stem segments were also used as explants. While only a quarter of explants could be established in culture, in contamination-free condition, good sprouting response (3-4 buds per segment) was obtained in certain PGR combinations. The sprouted buds developed into shoots on LP medium containing 5.0 <img src='/image/spc_char/micro.gif'> <i style="">M</i> BA; further subculturing of excised shoots for multiplication, however, resulted in drying up of shoots. Further work is required to overcome this difficulty.