Isoenzyme complexes as indicators of genetic diversity in white spruce, Picea glauca, in southern Ontario and the Yukon Territory. Formic, glutamic, and lactic dehydrogenases and cationic peroxidases

1978 ◽  
Vol 56 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Ruey C. Tsay ◽  
Iain E. P. Taylor

A centre of genetic diversity for white spruce, Picea glauca (Moench) Voss, is suspected in and around a refugial region in the Yukon Territory. Seed from the refugium (30 samples), a neighbouring region (42 samples) and from southern Ontario (50 samples) was examined for isoenzymes of formic (FDH), glutamic (GDH), and lactic (LDH) dehydrogenases and cationic peroxidases (CP). FDH patterns were uniform. There were three GDH bands which appeared in five patterns. Eleven isoenzymes of LDH were detected in 21 patterns. There were 25 CP bands and the pattern from each collection (containing 7–13 bands) was unique.The results from GDH, LDH, and CP analyses revealed differences between seed from the refugium and the adjoining regions. The patterns for LDH supported the hypothesis that the refugium was a centre of diversity but the GDH and CP patterns were more diverse outside the refugium. The LDH and CP analyses showed that the genetic resources of the two regions in the Yukon were more diverse than those in southern Ontario. Analysis of divergence showed that these differences were significant at the 1% level of probability.

2001 ◽  
Vol 31 (6) ◽  
pp. 943-949 ◽  
Author(s):  
M J.W Godt ◽  
J L Hamrick ◽  
M A Edwards-Burke ◽  
J H Williams

Genetic diversity within a white spruce (Picea glauca (Moench) Voss) seed orchard (consisting of 40 clones) and a jack pine (Pinus banksiana Lamb.) seed orchard (31 clones) was assessed and compared with genetic diversity in natural populations within the source area for the orchards. Genetic diversity was determined at 18 allozyme loci for seven white spruce populations and 27 loci for five jack pine populations, and the two orchards. Gene diversity maintained within the seed orchards (He = 0.157 for white spruce and 0.114 for jack pine) was similar to that found within the source area for each species (He = 0.164 and 0.114 for white spruce and jack pine, respectively). However, nine white spruce alleles and 12 jack pine alleles identified in the source area were not present in the seed orchards. These alleles occurred at low frequencies in the natural populations (mean frequency = 0.023 and 0.014 for white spruce and jack pine, respectively). Mean genetic identities between the seed orchards and their natural populations were high (>0.99), indicating that common allele occurrences and frequencies were similar between the orchards and their source area. One allele in the white spruce orchard and two in the jack pine seed orchard did not occur within the natural population samples. Simulations indicated that randomly reducing the number of clones within the seed orchards would decrease allelic richness slightly but would have little effect on overall gene diversity.


2005 ◽  
Vol 83 (9) ◽  
pp. 1096-1105 ◽  
Author(s):  
Om P. Rajora ◽  
Ishminder K. Mann ◽  
Yong-Zhong Shi

White spruce ( Picea glauca (Moench) Voss) is a characteristic primary species of the Canadian boreal forest region, where it occurs in conifer-dominated and mixedwood forest types. Genetic diversity and population structure of white spruce may differ between the conifer-dominated and mixedwood forest types owing to the inherent differences in stand structure and dynamics. The objective of our study was to determine genetic diversity and population structure of pristine white spruce stands as they occur in conifer-dominated and mixedwood forest types at the EMEND (Ecosystem Management Emulating Natural Disturbance) study sites in northern Alberta. Nuclear microsatellite DNA markers were used to examine genetic diversity and population structure of 16 pristine natural old-growth (≥100 years) white spruce stands (subpopulations) of fire origin; 8 from conifer-dominated and 8 from neighboring mixedwood forest types. High levels of genetic diversity were observed, as expected. The genetic diversity and genetic constitution of white spruce were similar between the conifer-dominated and mixedwood forest types. Most of the genetic variation resided within subpopulations, with only about 2% genetic differentiation detected among 16 subpopulations as well as among 8 subpopulations within the same forest type. The mean genetic distances among subpopulations within and between the forest types were similar. Our study suggests that white spruce genetic resources are similar in the conifer-dominated and mixedwood forest types located in the EMEND study area in northern Alberta, and it provides the benchmarks for determining and monitoring the genetic diversity impacts of forest harvesting and forest fires.


1954 ◽  
Vol 86 (4) ◽  
pp. 185-189 ◽  
Author(s):  
Howard A. Tripp

Maggots of Pegohylemyia sp. have been found inhabiting the cones of white spruce, Picea glauca (Moench.) Voss, in southern Ontario. The species was identified from a single male specimen as probably Pegohylemyia anthracina Czerny by the Swedish authority Dr. O. Ringdahl. Difficulty in rearing the maggots to the adult stage has delayed confirmation of this identification but it is expected that a good series of adults will be available shortly. In this paper, however, the emphasis is placed on the instars with an outline of the life cycle. It is shown that the second- and third-instar larvae are free-living, but the first-instar larvae moult to the second within the egg chorion.


1980 ◽  
Vol 17 (8) ◽  
pp. 1087-1095 ◽  
Author(s):  
J. Terasmae ◽  
H. L. Matthews

Study of late Wisconsin deposits in a small bog on the crest of Brampton esker (mantled by the Halton Till), about 30 km west of Toronto, Ontario, yielded a radiocarbon date of 12 320 ± 360 years BP (BGS-551) for a sample of white spruce cones that contained fully-developed seeds. This date on cones (in gyttja) provides an estimate of minimum age for the lower boundary of the spruce pollen zone in southern Ontario. Silty clay beneath the gyttja yielded leaves of Dryas integrifolia and pollen assemblages (a herb pollen zone) that indicate presence of a dwarf-shrub tundra (essentially treeless) type of vegetation.This study supports the Port Huron Stadial age (about 13 000 years BP) of the Halton Till that underlies the silty clay, and suggests an age of between 12 500 – 13 000 years BP for glacial Lake Peel in the Brampton area that preceded the glacial Lake Iroquois phase in the Lake Ontario basin.


2021 ◽  
Vol 1 (5) ◽  
Author(s):  
Azalea Guerra‐García ◽  
Tania Gioia ◽  
Eric Wettberg ◽  
Giuseppina Logozzo ◽  
Roberto Papa ◽  
...  

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