Clonal micropropagation of mature Larix

Abstract

Application. Mature Lark can be serially, clonally micropropagated in vitro. Potentially, the most promising mature phenotypes may be selected and rapidly cloned for outplanting.Abstract.Adventitious buds were developed in vitro from stems of elongating short shoots of mature European larch (Lark decidua Mill.). Tissue culture propagule populations thus generated, were similarly remultiplied in vitro. Elongation and rooting were routine. No vitreous or otherwise abnormal shoots were noted.

Elongation, rooting and acclimatization of micropropagated shoots from mature material of hybrid larch

“…This length of time in culture on medium containing both a cytokinin and an auxin differs from the protocol followed for several species of larch, including L. x eurolepis, where the explants from mature trees were transferred to media devoid of growth regulators 3 to 8 weeks after initiation (Bonga & Pond, 1991;Bonga & von Aderkas, 1988;Chesick et al, 1990;Diner, 1990). In addition, our cultures were initiated from stecklings that had been serially propagated every 2-3 years for 9 years.…”

“…Although in vitro shoots of Larix species were rooted before as short shoots and elongation occurred after acclimatization (Bonga &von Aderkas, 1988;Lalibert6 & Lalonde, 1988), rooting and acclimatization are generally more successful with longer shoots. With L. decidua the shoots had to attain a length of 10 mm (Diner, 1990) and those of Pseudotsuga menziesii, a length of 30 mm before they would root (Mapes et al, 1981) with an initial height of 41-60 mm giving the best percentage of plantlet survival in the latter (Mohammed & Vidaver, 1990).…”

“…With L decidua adventitious shoots were obtained from 19-year-old trees, rooting ranged from 53% to 81% (Diner, 1990) and 9 rooted plantlets were produced from 140-year-old trees (Kretzschmar & Ewald, 1994). Adventitious shoot formation from cultures of 30-year-old trees of L decidua, L. leptolepis and the hybrid, L. x eurotepis was reported by Bonga & Pond (199t) and Bonga & von Aderkas (1988) with limited elongation and rooting success.…”

Adventitious micropropagation of mature Larix decidua using dormant versus flushed axillary vegetative buds

“…In the latter case, important traits could be identified for elite genotypes, the tissues or organs of which might then be employed for vegetative propagation. There are some reports of organogenesis from mature conifers (Horgan and Holland 1989, Diner 1990, Bonga 1991, Dunstan et al 1992, Mac an t-Saoir et al 1992) using various tissue sources, though shoot elongation, rooting or even continued viability may not occur reliably (Bonga 1991). A factor further complicating use of mature tree tissues is their often brief availability during seasonal development and growth of sexual (Bonga 1984) and vegetative organs (Diner 1990, Mac an t-Saoir et al 1992 for use as source tissues for micropropagation.…”

“…A factor further complicating use of mature tree tissues is their often brief availability during seasonal development and growth of sexual (Bonga 1984) and vegetative organs (Diner 1990, Mac an t-Saoir et al 1992 for use as source tissues for micropropagation. Methods have been developed for micropropagation of mature larch using short shoots (Diner 1990). However, these actively growing, succulent source tissues are available for only a few weeks in the spring.…”