Induction and maturation of red spruce (Picea rubens S.)‎ and HY¬brid larch (Larix x Eurolepsis henry)‎ embryogenic cultures as AF-fected by abscisic acid and partial drying pretreatments of somatic embryo explants

Abstract EN

The ability of mature red spruce and hybrid larch somatic embryos to produce embryo-genic tissues in vitro was investigated following abscisic acid (ABA) and partial drying pre-treatment.

The resultant tissues were then transferred to various ABA-containing media and their capacity to give rise to well developed second-cycle somatic embryos evaluated.

In red spruce, the embryogenic potential improved with increasing ABA concentration (7.5-80 |iM) supplied during embryoid development.

Embryoids matured on 40 |iM ABA or more exhibited the same embryogenic potential as their zygotic counterparts excised from mature seeds.

Partial desiccation of mature embryoids resulted in a significant increase in embryogenic potential of red spruce as opposed to hybrid larch.

Serial reinduction of embryogenic tissue, however, repressed that potential in red spruce and enhanced it in hybrid larch.

In both species, maturation capacity of embryogenic tissue after 45 days increased steadily with increasing concentration of exogenous ABA ranging from 7.5 to 80 |iM.

However, hybrid larch tissue required activated charcoal pre-treatment prior to ABA exposure.