Genetic variation in the frost hardiness ofPodocarpus totara

Abstract

The late-winter frost hardiness of seedlings of eight provenances of totara (Podocarpus totara G.Benn. ex I)on) raised in a common environment was tested in a corarolled environment frost room. Frost damage was assessed visually. Frost hardiness temperatures of file provenances ranged from-5~ to-10~ A significant increase in frost damage occtared at lower temperattaes, and the frost hardiness of the wovenances was positively couelated with their altitude of origin. The possibility of allele frequency-depmdent selection for alleles con~elated with frost ~ was explored by aprelimin~ isozyme analysis of fottr variable loci in new foliage of tolara seedlings. Allele frequencies at one locus ofisocitrate dehy&ogenase ([dh-1) a0pemed significantly correlated with provomm~e frost MMiness. These results suggest that environmental pressmes have selected for frost hardiness in totam, and resulted in the evolution of populations of ~ adapted to cmrent local climates.

Altitudinal genetic variation in Pinus hartwegii Lindl. I: Height growth, shoot phenology, and frost damage in seedlings

“…ex Don.) (Hawkins et al, 1991). Similar patterns have been described for Mexican coniferous populations distributed along the altitudinal gradients, such as Pinus devoniana Lindl.…”

Provenance variation in Podocarpus totara (D. Don): Growth, tree form and wood density on a coastal site in the north of the natural range, New Zealand

“…Hawkins et al (1991) using the same seedlots found that frost hardiness of P. totara was positively correlated with altitude of seed origin for a limited selection of central to southern region North Island provenances, ranging from 30-540 m a.s.l. in altitude.…”

Seasonal frost tolerance ofHebespecies and cultivars

“…(Bannister & Lee 1989), Leptospermum scoparium Harris & Decourtye 1991), and Podocarpus totara (Hawkins et al 1991). For example, differences in maximum summer frost hardiness temperatures of Nothofagus were small between populations from different altitudes, but in mid winter hardiness temperatures were -11.5°C for high altitude populations and only -4.5°C for low altitude populations (Greer et al 1989).…”