ALBERT

Description: Newly germinated seedlings of 66 open-pollinated white spruce Piceaglauca (Moench) Voss families from 11 native stands in southeastern Ontario were investigated for responses to declining photoperiod under controlled environments. Amount of height increment (free growth) during a period of declining photoperiod was studied. Variation in duration of free growth was found mostly associated with the family-within-stand component. The stand effect was negligible and decreased as seedlings aged. Lack of stand differentiation suggests that white spruce stands in. southeastern Ontario may have originated from the same base population. High genetic variation at the family level may reflect an adaptive strategy to cope with the extremely variable local climate.

Description: Fifty-three family-structured provenances of lodgepole pine (Pinuscontorta var. latifolia) growing at a single test site near Prince George, British Columbia, were rated visually by two different methods for needle casting caused by Lophodermellaconcolor in 1982 and 1984. Analysis of variance indicated little variation due to families and much due to provenance. There were consistent year-to-year trends among the provenances and the two rating methods correlated by 0.9. This variation was significantly correlated with longitude and elevation but only slightly with latitude. Damage among the 41 provenances that are adapted to the continental climate of interior British Columbia increased with elevation.

Description: Thirty provenances of lodgepole pine (Pinuscontorta Dougl.) test stock raised at two nurseries, Cowichan Lake (coastal British Columbia) and Red Rock (interior British Columbia), were assessed in two 15-year field trials. Analyses indicated three broad geographic regions of genetic differentiation in British Columbia: coast, coast–interior transition, and central and southern interior. Provenance elevation was found to have a strong influence on growth. The results suggest that the present seed transfer guidelines for lodgepole pine in the interior region of this province are conservative enough to prevent the use of maladapted seed sources. Nursery effect declined over a period of 15 years, while provenance differences increased with the age of the trials. Interactions between provenances and sites also increased after age 9. This suggests that the effect due to seedling culture and environment in the nursery is short-term relative to the influence of the genetic component. Nursery growth was generally not a good predictor of provenance field performance.

Description: Early, rapid tests are required to ascertain the structure of white spruce Piceaglauca (Moench) Voss populations of southeastern Ontario, where valuable but limited seed sources have been located through field trials. As a significant phenological character associated with growth and hardiness, rate of flushing was monitored under controlled environments in six half-sib families from each of four stands of white spruce located in southeastern Ontario. Whereas no significant variation occurred among stands, highly significant differences occurred among families within stands throughout the flushing period. Results are interpreted as a reflection of coadaption of populations to the timing of environmental hazards. A comparison is made with the minor geographic and pronounced annual variations in occurrence of last spring frost.

Description: Resistance of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) to western gall rust (Endocronartium harknessii (J.P. Moore) Y. Hiratsuka) was compared between 21-year field infection trials and inoculation of 2-month-old seedlings. The seedlings were produced from seed stored since the original field plantings. Virtually all of the seedlings from families identified as susceptible in the field produced galls in the inoculation trial, only 1% of seedlings from these families did not develop galls. Nearly half the seedlings in families classed as resistant in the field trials did not form galls 13 months after inoculation. Only one of these seedlings developed galls in the following 2 years. Seedling inoculation provides a simple early test to assess field resistance to gall rust of lodgepole pine seedlots, and an efficient way to cull at least the most susceptible ones.

Description: Forty-five provenances or progenies of Piceaglauca (Moench) Voss, P. sitchensis (Bong.) Carr., P. engelmannii Parry, and their various F1 and F2 hybrids and backcrosses were tested in two replicated and one unreplicated experiments at Chalk River, Ontario. At ages 10, 15, and 22 years from seed, large differences in survival, growth, and hardiness were found. Hardiness was closely correlated with the proportion of Piceaglauca germ plasm. Implications for the use of hybrids in silviculture are discussed.

Description: We examined the genetic variation of ecophysiological traits within and among 40 red alder (Alnusrubra Bong.) provenances (two families per provenance) in a common-garden experiment in the summer of 1993. The provenances were representative of the entire species range in British Columbia, Canada. We found significant genetic variation among provenances (P 〈 0.001) in photosynthetic rate (A), mesophyll conductance (gm), transpiration rate (E), stomatal conductance (gsw), stomatal sensitivity to water vapour pressure deficit (SENSVPD), intercellular to ambient CO2 concentration ratio (Ci/Ca), and midday xylem water potential (ψ). Photosynthetic water-use efficiency, however, did not differ significantly among provenances. There were no significant differences between families within provenance for any of these variables. A weak but significant geographic trend was detected in ecophysiological traits: ψ, A, gm, and E increased, and SENSVPD decreased, from southeast to northwest. Photosynthetic rate, E, gm, gsw and ψ were positively related to each other, but negatively correlated with SENSVPD. Ci/Ca was negatively correlated with gsw. These correlations indicate that red alder might have undergone genetic differentiation in drought resistance.

Description: Seedlings and grafts from lodgepole pine (Pinuscontorta var. latifolia Dougl.) plus-tree selections in British Columbia were established and maintained in the greenhouse under 24-h photoperiod for 6 months. Subsequently, seedlings were outplanted in the nursery and grafts in a breeding orchard at Red Rock Research Centre. In the 5th year from seed (1980), the proportion of flowering trees and the average number of seed cones per flowering tree were roughly six times greater for accelerated growth seedlings (81%, 18 flowers/tree) than for controls (12%, 3.6 flowers/tree). Differences in pollen cone production were of similar magnitude. Flower enhancement in seedlings carried over into the next year. Grafted trees were considerably less productive than seedlings. At age 5 a mean of four female strobili were produced on 77% of treated grafts compared with 1.6 strobili on 36% of untreated controls. These values decreased slightly in 1981. Pollen production was yet to be observed on grafted materials. While the superiority in height of accelerated seedlings relative to controls has steadily decreased since time of establishment, large differences in number of branches per tree and biomass remain. Root systems of accelerated seedlings generally were excessively pot-bound, resulting in considerable root grafting after outplanting. The possible causes of increased flower production in accelerated growth trees are briefly discussed. The production of both pollen and seed cones in numebrs large enough to support a modest breeding scheme greatly increases the opportunity for rapid generation turnover in forest trees such as lodgepole pine and permits greater flexibility in planning a long-term tree improvement program.