Genetics of Cone Morphology of Black Spruce [Picea-mariana (Mill). B. S. P.] in Newfoundland Canada

The paper presents the results of a study conducted to determine the relative role of genotypic and environmental control over characters of cone morphology and seed weight in black spruce (Picea mariana (MILL.) B.S.P.) A three-stage cluster sampling scheme was adopted with the sampling stages of populations, trees within populations and cones within trees. Nine characters of cone morphology were measured on each cone and mean 1,000-seed weight was determined for each tree. Statistical analyses comprised (1) calculation of popula­ tion means and standard deviations for each character, (2) cone length-cone diameter correlations at the populations and tree levels, (3) hierarchical analyses of variance and (4) comparison of the cone length-cone diameter correlations with similar values obtained six years earlier. Genetic ana­ lyses consisted of (1) calculation of repeatibility with stand­ ard error and confidence limits for each character at the population level as estimates of heritability; and (2) multiple regression analysis for each character. The latter was con­ ducted using the stepwise zig-zag procedure with cone character as the dependent variable and 12 environmental factors together with their squares and first order inter­ actions as independent variables to identify the subset which contributes most to the variation in the character. Though the means and repeatabilities of all characters vary with populations, no geographic trends can be dis­ cerned. Repeatability values have been shown to be good estimates of heritability. All characters are under statisti­ cally significant genotypic as well as environmental con­ trol and the most important subset of the latter has been identified. Cone length, diameter, and oven dry weight as well as dimensions of the middle scale are under strong, and length and width of the base and tip scale, under weak genotypic control. The earlier indications of pleiotropic control over cone length and diameter is supported. Seed weight is under weak environmental control

All-Range Black Spruce Picea-Mariana Provenance Study in Newfoundland: Performance and Genotypic Stability of Provenances

The paper presents ten year results of a three-location all range black spruce provenance study in Newfoundland, conducted in six-replicated triple lattice design experiments. The data, collected in 1980 on 1979 and 1980 heights, 1980 diameter at 0.3 m, height growth in the 1974-80 period and in 1980 were analysed with analyses of variance by and over locations, BoNFERRONI t-tests, step-wise regression analyses and evaluation of the provenances for productive quality and genotypic stability, using height growth in the 1974-80 period as the criterion. Lattice design proved significantly effective in removing intra-replication variation and in improving efficiency compared with the randomized complete block design. High intra-provenance variation was noticed, indicating heterogeneity of the provenances and the possibility of obtaining enhanced genetic gains by intensive family selec­ tions within superior provenances. Most of the provenances in the fourth quartile belong to the region between latitudes.45°-49' 6 N and longitudes 60°-84° W. Variation in the performance of provenances among locations was detected in arrays and confirmed and quantified by analyses of variance over locations. Initial height growth in nursery, six-year growth in field and total growth are significantly correlated with each other. Superior provenances have relatively low genotypic stabi­ lity, which appears to be due to their high heterozygosity. Eight promising provenances have been tentatively iden­ tified by a combined evaluation of the productive quality and genotypic stability of all provenances. These are: MS. 1531, S.6905, MS. 1528, MS. 1533, S.6927, 370, S.6911 and 353

Variation and Genotypic Stability of Picea mariana (Mill.) B.S.P. in Newfoundland, Canada

This paper presents results of a ten-year black spruce (Picea mariana (MILL.) B. S. P.) provenance study in New­ foundland, Canada. The data on ten-year height, height growth in the field up to ten year age and in the tenth year and diameter at 0.3 m were studied together with evaluation of genotypic stability and productive quality of the provenances. Provenances were significant sources of variation at four locations, where intra-provenance vari­ ation was small and vice versa at the other three locations. Height growth in the field showed weak east-west and north-south trends in the mainland and Newfoundland­ Labrador provenances respectively. Greater height growth of the fast-growing provenances was not dependent only on the growth in the nursery but was retained in the field also. Provenances in the fourth quartile had relatively low genotypic stability, which would make choice of suitable provenances difficult if precise information about the en­ virornnent of the planting site is not available. However, recommendations have been made for planting sites re­sembling the test locations and for sites whose environ­ mental conditions are not known or do not resemble those of the test locations

Genetics of wood characters of black spruce (Picea mariana (Mill.) B.S.P.) in Newfoundland, Canada

The variation and relative control of genotype and envi­ ronment over 11 wood characters in black spruce (Picea mariana (MILL.) B.S.P.) were studied to identify populations with superior pulping qualities. A four- and three-level cluster sampling scheme was adopted and the statistical and genetic analyses comprised analyses of variance, BoN­ FERRONI t-tests, repeatability calculations and multiple re­ gressions. Trees, discs and populations rank from highest to lowest as sources of variation in most characters. Within trees, the trend varies with character. There are weak north-south trends in relative densities, alcohol-benzene and sodium hydroxide solubilities and fibre length and wall thickness. Regression analyses of the ,squares of longitude and alti­tude show a negative and a positive influence respectively on sodium hydroxide solubility. Temperature and precipitation appear most frequently in different combinations in other regression equations. Repeatability values are good estimates of heritabilities. All characters except fibre wall thickness have high heritability (R ): 0.30). The environ­ mental factors studied have a significant influence on the non-genotypic portion of variation in all characters except fibre and lumen diameters (tangential section) and alcohol­ benzene .solubility. Populations 11, 16 and 19-23 have superior pulping qualities

The Potential of Poplars in the Boreal Regions I. Survival and Growth

The paper presents the results of a two-stage trial of 32 clones of poplar species and their hybrids in a nursery from 1972 to 1974 and four replicated field experiments during 1978-81 in the boreal region of Canada in New­ foundland. Analysis of variance, S-N-K test among clones and single degree of freedom contrasts among classes, formed on the basis of one common parent, were conduc­ ted for survival and height in the nursery. Survival was 70-86%, 54-70% and 38-54% respectively in the high, medium and low survival clones. The good, medium and poor growing clones achieved heights of 174.4-216.0 cm, 170.1-174.0 cm and 136.7-166.8 cm respectively after the root system had been established. The classes were hete­ rogeneous but the clones were fairly homogeneous. Hetero­ sis in growth was noticed in several cases. Good as well as poor rooting ability of the parent species was found in the hybrids. The four sites for field experiments were selected in the productivity class I and II areas after detailed chemical and physical soil analysis. One-year old rooted cuttings were planted in six-replicated randomized complete block design experiments. Analyses of variance by locations we­ re conducted on the survival and growth data at four-year age. This was followed by Bonferroni t-tests among clones ang single degrees of freedom contrasts among classes. Use of rooted cuttings, combined with scarification, weed eradication and liming of the field planting sites is essen­ tial for success as well as achieving uniformity of growth within clones. The best time for field planting appears to be the last week of June to the first week of July. Sites vary considerably in survival as well as growth and the good, medium and poor performers in all characters are different at different sites, details of which have been provided. The results provide guidelines for selection of clones best suited for the boreal environments represented by the four sites studied

Early growth of some progenies from two phenotypically superior white spruce provenances in Central Newfoundland

The nursery phase of the study started in 1971 to verify the genetic superiority of phenotypically superior trees of white spruce (Picea glauca (Moench)Voss)from two locations in central Newfoundland, Canada, was completed in 1975. Although statistically significant differences in four-year growth between the two locations were detected there were no such differences between the progenies of "plus" and "ordinary" trees at either location. The superiority of "plus" trees over "ordinary" trees may be due to more out-breeding in the former than in the latter class of trees. Heritability show the possibility of more genetic gain by selection from "plus" trees than that from "ordinary" trees. Establishment of a seed orchard of "plus" trees from each location is recommended