Genetic Variation in Stone Pine Half-Sib Progenies

Total height, annual height growth, root collar diameter, total number of branches and total number of buds around the leader bud were recorded at age 6. The experimental material was included 136 half-sib families originating from stone pine natural populations from the Carpathian Mountains. Population samples were included in a randomized complete block experiment with four replications and ten seedlings per family per replication. Highly significant (p<0.001) family variation for all traits was detected. Very high family heritabilities were estimated for total height (hf^2 =0 .968), root collar diameter (hf^2 = 0.938) and total number of branches (hf^2 = 0.966). Genetic correlations between total and annual height growth and root collar diameter were high or very high, ranging between 0.804 and 0.969. These correlations indicated favorable conditions for obtaining substantial genetic gain for a combination of these traits. By selecting the best 30 to 45 families, genetic gains in total height growth and diameter between 28.8 % and 23.4 % and between 18.8 % and 15.3 %, respectively, could be achieved. Suggestions for a breeding strategy are made.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

Results after 19 years of testing in a Pinus strobus x P. wallichiana F1 hybrid population

<p>Full-sib families were generated from a factorial design between seven female trees of P. strobus and four male trees of P. wallichiana to combine the rapid growth of former species with high resistance to blisterrust (Cronartium ribicola) of the latter one. At age two the hybrid families were artificially inoculated with blister-rust and at age six they<br />were field planted. Total height growth, diameter at 1.3 m, basal area, stem volume, stem straightness and tree survival were measured<br />at age 19 after planting. Significant (p&lt;0.05) and highly significant (p&lt;0.01; p&lt;0.001) differences among female effects were found for all tested traits including survival suggesting that nuclear additive genes<br />controlled these traits. Male effects were significant only for stem straightness. In all but one trait the σ2GCA: σ2SCA and σ2GCA-F : σ2GCA-M ratios were in favour of additive variance suggesting<br />that this variance should be used in the breeding strategy. Narrow-sense heritability at family level was 0.778 for volume growth rate<br />and 0.861 for survival; such high values indicate that the breeding programme, has good chances of success. Two of the 11 tested parents<br />exhibited significant positive g.c.a. effects for survival after heavy blister-rust inoculation. One parent exhibited highly significant<br />positive g.c.a. effects for volume growth rate. The three good general combiners should be taken into account in the breeding programme.<br />Estimate of the high-parent heterosis was negative for the volume but positive for survival. For volume, the hybrid mean was 5.9% lower<br />than the mean of the eastern white pine but 85.4% greater than blue pine bulk lot for survival. Estimate of low-parent heterosis for survival<br />was also positive; i. e. the hybrid population mean was 537.5% greater than eastern white pine. If the hybrids will be used in operational<br />planting programs, a variable genetic gain between 6.0 and 10.5% for volume and between 6.8 and 9.6% for survival could be<br />achieved.</p

Genetic structure in Pinus cembra from the Carpathian Mountains inferred from nuclear and chloroplast microsatellites confirms post-glacial range contraction and identifies introduced individuals

ISSN:1614-2950ISSN:1614-294

Pines

Pinus is the most important genus within the Family Pinaceae and also within the gymnosperms by the number of species (109 species recognized by Farjon 2001) and by its contribution to forest ecosystems. All pine species are evergreen trees or shrubs. They are widely distributed in the northern hemisphere, from tropical areas to northern areas in America and Eurasia. Their natural range reaches the equator only in Southeast Asia. In Africa, natural occurrences are confined to the Mediterranean basin. Pines grow at various elevations from sea level (not usual in tropical areas) to highlands. Two main regions of diversity are recorded, the most important one in Central America (43 species found in Mexico) and a secondary one in China. Some species have a very wide natural range (e.g., P. ponderosa, P. sylvestris). Pines are adapted to a wide range of ecological conditions: from tropical (e.g., P. merkusii, P. kesiya, P. tropicalis), temperate (e.g., P. pungens, P. thunbergii), and subalpine (e.g., P. albicaulis, P. cembra) to boreal (e.g., P. pumila) climates (Richardson and Rundel 1998, Burdon 2002). They can grow in quite pure stands or in mixed forest with other conifers or broadleaved trees. Some species are especially adapted to forest fires, e.g., P. banksiana, in which fire is virtually essential for cone opening and seed dispersal. They can grow in arid conditions, on alluvial plain soils, on sandy soils, on rocky soils, or on marsh soils. Trees of some species can have a very long life as in P. longaeva (more than 3,000 years)