Selfing and correlated paternity in relation to pollen management in western red cedar seed orchards

We used microsatellite genetic markers to evaluate the mating system of western red cedar (Thuja plicata Donn ex D. Don) under various seed orchard pollen management schemes. We primarily examined whether supplemental mass pollination (SMP) can reduce the observed selfing rates. Pollen blowing and “hooding” were also examined in smaller tests. Only SMP was consistently effective in reducing the selfing rate, from 30% to 20%. The correlation of paternity was quite high (60%–90%) in two of three orchards, and in these two orchards the application of SMP reduced this correlation by about 10% as well. The correlation of paternity is the fraction of full-sibling vs. half-sibling progeny, and unbiased estimates can be obtained with few loci, even single loci, in contrast to other types of paternity analysis. We also find the microsatellite amplicon sizes should be pooled into “bins” of 2–4 nucleotides, owing to unintended errors of assay; otherwise the estimates are biased. This new feature of mating system estimation was incorporated into the computer program MLTR.

Peculiarities of seasonal development and influence of ecological factors on the growth of thuja giant (Thuja Plicata Donn Ex D. Don) in the conditions of introduction in the right-bank forest-steppe of Ukraine

Generalization and analysis of experimental data concerning peculiarities of passing and duration of various phenological phases of Th. plicata, their consistency with the sums of effective temperatures is provided in the article. Conducted researches based on observations and mathematical processing allowed to reveal the regularity of passing of all vegetative and generative phases in the area of introduction and to reveal the dependence of these processes on ecological factors. It was found that the vegetation period of this species is 151 ± 3 days. Influence of nature and degree of temperature, air humidity and rainfall on the growth of shoots were also determined. It turned out that air temperature has the greatest influence on the growth peculiarities of one-year shoots. Growth of shoots begins after changing of the average daily temperature above +9°C. Culmination of increments is observed in May, when the temperature is 13–18°С. Then, increments are fading with the increase in temperature and decrease in humidity and the second wave of growth occurs in August. Shoots completely finish their growth in September. Precipitation and humidity do not have a significant effect on the growth of shoots.

Культивари виду Thuja plicata Donn ex D. Don у Правобережному Лісостепу України та можливості їх використання в садово-парковому будівництві

Досліджено внутрішньовидове різноманіття виду Thuja plicata Donn ex D. Don у Правобережному Лісостепу України. Встановлено, що із 54 відомих культиварів виду в дендрологічних парках регіону вже багато років успішно зростають два: Th. p. 'Zebrina' і Th. p. 'Aureovariegata'. За останні 10 років також були введені Th. p. 'Dura' та Th. p. 'Whipcord'. У декоративному садівництві поширені такі культивари Th. plicаta: Th. p. 'Atrovirens', Th. p. 'Aureovariegata', Th. p. 'Can-Can', Th. p. 'Daniellow', Th. p. 'Dura', Th. p. 'Excelsa', Th. p. 'Gelderland', Th. p. 'Goldy', Th. p. 'Kornik', Th. p. 'Whipcord', Th. p. 'Zebrina' та Th. p. 'Zebrina Extra Gold'. Для характеристики різноманіття культиварів Th. plicаta, що ростуть у Правобережному Лісостепу України, використано систему класифікації формового складу поліваріантних видів Р. В. Кармазіна. Згідно з цією класифікацією, досліджувані рослини Th. plicаta належать до надгрупи В (рослини з лускоподібною хвоєю). Із 12 культиварів до групи І віднесено шість; до групи ІІ – три; до групи ІІІ – три. Визначено біометричні показники досліджуваних культиварів. Виділено культивари Th. plicаta, які поширені в районі досліджень за найбільш істотними декоративними ознаками, а саме: за забарвленням хвої, формою крони та висотою (низькорослі форми). Враховуючи їхні декоративні якості, надано рекомендації щодо застосування у різних типах насаджень: солітерах, групах, алеях, живоплотах, під час створення альпінаріїв та контрастних композицій.

Histology of resin vesicles and oleoresin terpene composition of conifer seeds

The seed coats of several conifers contain terpene-filled resin vesicles, which may be involved in the protection of the dormant embryo and the seed storage tissue against herbivores or pathogens. We analyzed the terpenoid composition of seeds from four Abies species (Abies amabilis Douglas ex J. Forbes, Abies balsamea (L.) Mill., Abies grandis (Douglas ex D. Don) Lindl., and Abies lasiocarpa (Hook.) Nutt.), two Thuja species (Thuja plicata Donn ex D. Don and Thuja occidentalis L.), and three Tsuga species (Tsuga canadensis (L.) Carrière, Tsuga mertensiana (Bong.) Carrière, and Tsuga heterophylla (Raf.) Sarg.) and examined histological features of resin vesicles in seeds from one species from each genus. Resin vesicle morphology was generally similar among the species analyzed. The composition of the seed terpenes varied largely between species. The described seed terpene profiles of the nine species will serve as a foundation for future studies into the function of seed terpenes and resin vesicles in the seed coat.

Assessment of armillaria root disease infection in stands in south-central British Columbia with varying levels of overstory retention, with and without pushover logging

This trial, conducted near Nakusp, British Columbia, compares pushover logging (combination tree felling and root removal technique using large machines to push trees out of the ground) with handfalling logging (no root removal) for effects on the incidence of armillaria root disease in postharvest regeneration. Pushover logging did not reduce levels of root disease, expressed as percentage tree mortality, over handfalling harvesting on this site. High variability of measured disease levels within some treatments and few replicates lowered the power of the trial. However, in addition to being statistically insignificant, the mean differences between the two main treatments were small and biologically uninteresting, and the response was inconsistent in direction. The trial also included three mature timber retention levels as treatments, and there seemed to be a trend of declining root disease with increased retention of stems. This phenomenon should be further investigated as current literature is not clear on the response of armillaria to partial harvesting. There was a strong suggestion of a difference between susceptibility of natural and planted seedlings to armillaria root disease, with natural regeneration being less susceptible. Thuja plicata Donn ex D. Don was less affected by armillaria root disease than other species in this trial, whether it was planted or naturally regenerated.

Effects of leaching on fungal growth and decay of western redcedar

We tested the effect of leaching on the concentration of western redcedar (WRC; Thuja plicata Donn ex D. Don) heartwood extractives that are known to exhibit antimicrobial activity and correlated this with fungal growth and decay. We assessed the extractive tolerance of the following fungal species: Acanthophysium lividocaeruleum , Coniophora puteana , Heterobasidion annosum , Pachnocybe ferruginea , Phellinus sulphurascens , and Phellinus weirii by measuring their growth rate (mm/day) on media with or without WRC leachate. These data were correlated with the ability of the fungal species to grow on and decay leached versus nonleached WRC. We used an ergosterol assay to estimate growth and a standard soil-block test to assess decay. We estimated that leaching reduced the concentration of 5 major extractives: (–)-plicatic acid, β-thujaplicin, γ-thujaplicin, β-thujaplicinol, and thujic acid by ~80%. Phellinus sulphurascens exhibited the lowest extractive-tolerance in vitro, grew poorly on and caused minimal decay in nonleached WRC, but it grew well on and decayed pine and leached WRC. Coniophora puteana, H. annosum, and P. weirii displayed moderate to high tolerance to leachate, grew on and caused decay in nonleached as well as leached WRC, but their growth and decay were always greatest on leached WRC and pine, suggesting that leaching enhances decay by these fungi. Acanthophysium lividocaeruleum and Pachnocybe ferruginea exhibited high extractive-tolerance. Whereas A. lividocaeruleum clearly caused decay on all types of wood, no decay was observed with Pachnocybe ferruginea, which grew very slowly in the different wood species, and it may or may not be able to decay wood.