The possibility of early testing coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) for Swiss needle cast (SNC; caused by Phaeocryptopus gaeumannii (Rohde) Petrak) tolerance ...was investigated using 55 Douglas-fir families from western Oregon. Seedlings were inoculated with P. gaeumannii naturally in the field and were visually scored for a variety of SNC symptom traits (i.e., needle and foliage color, and retention) at the seedling stage (age 2) and in "mature" (ages 10 and 12) trees at two test sites for both the seedling and mature ages. Seedlings were also assessed in the laboratory for SNC symptom traits, for proportion of needle stomata occluded with pseudothecia (PSOP), and for amount of P. gaeumannii DNA in needles. Although families differed significantly at both ages for all SNC symptom traits and for PSOP, they did not differ for amount of fungal DNA. Thus, genetic variation in SNC symptoms appears to be primarily due to differences in tolerance to the disease rather than to resistance to infection per se. Estimated individual-tree heritabilities for SNC symptom traits were low to moderate (mean h(i)2 = 0.19, range 0.06-0.37) at both ages, and within each age-class these traits were moderately to strongly genetically correlated (mean r(A) = 0.69, range 0.42-0.95). Type B genetic correlations between SNC symptom traits in seedlings and mature trees ranged from 0 to 0.83 and were weakest for traits measured in the laboratory. Genetic gain estimates indicated that family selection for SNC tolerance (i.e., greener needles or greater foliage retention) at the seedling stage can be very effective in increasing tolerance in older trees.
Abies magnifica A. Murray bis var. critchfieldii var. nov. Lanner (Critchfield red fir) is described. The new variety comprises the southernmost Sierra Nevada populations of California red fir. It ...differs from the typical variety in having smaller cones with protruding cone bracts. Because of the protruding bracts, populations of the new variety have been assumed to be disjuncts of the bracted A. magnifica var. shastensis Lemmon (Shasta red fir), described over a century ago from Mt. Shasta and considered present in NW California and SW Oregon. However, geographic patterns of morphological variation, artificial crossing results, and recent molecular studies indicate that Shasta red fir consists of California red fir introgressed by noble fir (A. procera Rehder), and that the new variety is not hybridized with noble fir.
(1) Variation in the physical environment was investigated at scales of 0.1-50 m in the understorey of a southern Quebec forest, dominated by Acer saccharum and Fagus grandifolia, to determine if the ...spatial heterogeneity necessary to account for the evolution and maintenance of genetically diverse populations of forest plants exists in this old-growth forest. (2) To characterize spatial heterogeneity in the understorey during the late summer, soil pH and the availability of K+ and NO3(-1) ions in the soil solution were measured. The sampling programme involved analysis of replicate soil cores at 555 points dispersed throughout a 50-m X 50-m area in a valley previously undisturbed by human activities. (3) A geostatistical analysis demonstrated that all three edaphic measures are predictably similar up to about 2 m, but that at greater distances the predictability is negligible and the environmental regime is best estimated by the mean for the site as a whole. (4) These results demonstrate environmental variance at scales relevant to seed dispersal and genetic neighbourhood size in understorey herbs such as Impatiens. This spatial pattern of environmental variation may contribute to the maintenance of genetic variation through selection of locally adapted subpopulations.
The 7th meeting of the “Section Forest Genetics/Forest Tree Breeding” and the German Dendrology Society (DDG) took place in Ahrensburg/Schleswig-Holstein from September 12–14, 2022. The focus of the ...three-day lecture event was on "Contributions of Forest Plant Breeding and Forest Genetics to the Forest of Tomorrow". There was more than enough reason for the conference. Climate change is becoming more and more obvious. The effects of the excessively dry and warm years in large parts of Germany pose challenges for forest owners and managers. With the meeting we tried to answer some of the questions. At the conference, 51 presentations were given, which were assigned to 10 blocks: Methods, Resistance, Woody Plant Physiology I and II, uropean Beech, Breeding, Differentiation, Alternative Tree Species, Red Oak and Forest Reproductive Material. The conference ended with a half-day excursion to a 60-year-old stand of Monarch birch (Betula maximowicziana), a former provenance trial. At the object a lesser-known tree species of East Asia, knowledge and practical experience were exchanged. Another excursion point was a progeny test for use in short rotation set up by the Thünen Institute of Forest Genetics in strips. For the existing silvoarable agroforestry system (trees with arable crops), a concept for a silvopastoral system (trees with livestock) with chickens or calves was developed together with the Thünen Institute of Organic Farming. In preparation for grazing, half of the elevenyear- old woody strips were harvested during winter and used for energy production. The remaining growth as well as that from root shoots and sockers provide shade and shelter for the brother cocks. The meeting is held as part of the Charta für Holz 2.0, which aims among other things to increase the usable forest wood potential. The conference builds on the following priorities in the field of action Resource Forest and Wood of the Charta: • Sustainable wood supply: productivity and management, Cultivation of productive tree species, guarantee the supply of softwood, Forest tree breeding / forest genetics • Conservation through sustainable use: risk minimization (forest conservation, rotation length, forest conversion), adaptation of forests to climate change, crisis management In order to make the results of the event, which was well attended by 85 participants from Germany and Austria, accessible to a broad public, the content of selected presentations is published. The authors are responsible for the content of the ontributions.
We screened six populations of the clonal forest floor moss Plagiomnium affine from forests of different ages for genetic variation at 23 allozyme loci. Samples consisting of two adjacent, ...unconnected shoots were taken at regular intervals along one transect from each population. Transect lengths varied from 22 to 52 m, depending on the size of the local populations. From a sample of 602 shoots, we detected a total of 16 haplotypes, of which two were widespread and 12 were unique to single populations. Allelic variation, as measured by allelic richness and Nei's allelic diversity ($\text{H}_{\text{s}}$), was significantly correlated with forest age, when calculated at the ramet level, and nearly so when calculated at the genet level. Widespread haplotypes dominated the younger forest stands, whereas local haplotypes had a higher abundance in older forest stands. Together, these results indicate that populations are subject to continuous recruitment and that genetic variation accumulates as the forest ages.
The silvery gibbon (Hylobates moloch), endemic to the island of Java, relies on closed-canopy, lowland evergreen forest for its survival. Because Java has lost over 91% of its original forest, ...silvery gibbons currently occupy small, isolated forest fragments and are threatened with extinction. To contribute to a comprehensive conservation strategy for this species, we analyzed the mtDNA control region of 31 silvery gibbons representing most remaining populations. Our results suggest the presence of at least two genetically differentiated lineages: a "western" lineage, represented by the largest remaining natural population in Gunung Halimun National Park and a "central" lineage, consisting of smaller, more isolated populations in and around the Gunung Masigit/Simpang/Tilu complex, Gunung Gede/ Pangrango, and Gunung Slamet. These two lineages, at a minimum, represent different management units that should, except in the most dire circumstances, be managed separately.
The transgenic poplar (Populus tremula L.) was obtained by transfer of the ugt and acb genes via triparental mating, which was employed to deliver large fragments of TDNA as a cluster. Freshly ...harvested seeds of local poplar were placed on MS agar medium and plantlets were obtained. After 1 year of subcultivation, plantlets were infected with a transconjugant of triparental mating with target ugt and acb genes into axillary buds. The transformed sprouts so obtained were cut and subcultivated on agar medium with an addition of 0.6 mg/l indole-3-butyric acid as an auxin source. The transformed sprouts showed GUS activity and resistance to gentamycin and kanamycin. The integrity of the target ugt and acb genes into poplar genome was demonstrated via PCR and Southern blot hybridisation. The transgenic poplar plants revealed a higher growth energy, corresponding to a higher content of IAA as opposed to control plants. Both transgenic and non-transformed plants were potted into soil for outdoor acclimatisation and subsequently transferred to earth in beds. Growing outside during 3 years, the transgenic poplar demonstrated a higher growth rate with fast bud and branch development.
A field study in the Cofre de Perote region found that edible mushrooms play an important role in the socio-economics activities of the local population. Several very old common names indicate a ...long-standing traditional knowledge about this regional resource. Recent changes in marketing mushrooms are evident.
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