Snow mold fungi affect the seedlings of various conifer species such as spruce, fir, pine and juniper under snow (Butin, 1995;Sinclair & Lyon, 2005). The two types of snow mold diseases are snow blight and brown felt blight. The major causal agents of snow blight are Gremmenia (formerly Phacidium) abietis, G. infestans and Lophophacidium hyperboreum, which all produce annual mycelium on plant surface (Sinclair & Lyon, 2005). Those of brown felt blight are Herpotrichia juniperi and Neopeckia coulteri, which grow perennially on plant surfaces (Sinclair & Lyon, 2005). Both types of snow fungi produce ascospores in summer or autumn (Sinclair & Lyon, 2005).Snow blight and brown felt blight have been reported from boreal and alpine regions of Europe, Asia and North America where deep snow covers the land (
This study is the first large‐scale genetic population study of the three dominant tropical species of seagrass in the southern Philippines. The aim was to understand the genetic diversity, population structure, and clonality of Enhalus acoroides, Thalassia hemprichii, and Cymodocea rotundata for appropriate ecosystem management and conservation. Population genetics analysis for the 15 sites was performed by using polymorphic microsatellite markers within the regional geographical scale. The results showed that the population genetic parameters across the Mindanao region are low to high. Overall, Clonal richness was highest in E. acoroides, followed by T. hemprichii and C. rotundata, indicating sexual reproduction is prevalent. The largest genet found in the study was at Rizal, Northern Mindanao, wherein throughout the sampling area only one genet was identified. The mean FIS (coefficient of local inbreeding) values were positive (heterozygous deficit) with some sites deviating from Hardy-Weinberg equilibrium. Significant pairwise population genetic differentiation was found among many sites. Isolation by distance (IBD) was detected in T. hemprichii and C. rotundata (P < 0.05) but not in E. acoroides (P = 0.253). IBD is present among populations, maybe influenced by the ocean current system in the southern Philippines, but it has to be confirmed yet in the future study. If the goal is to maintain the genetic connectivity of these ecologically important seagrass species, conservation planning and implementation of marine protection should be considered at the regional scale – following the Mindanao Ocean currents.
Serpula himantioides is a globally distributed saprotrophic fungus that is observed on all continents except Antarctica (Carlsen et al., 2011).Serpula himantioides mainly occurs on hardwood and softwood trees in natural environments, but it can also inhabit wooden structures (Carlsen et al., 2011). Brown rot caused by S. himantioides in the roots and stem base has been reported on various hosts (e.g. Pseudotsuga menziesii, Larix kaempferi) (Seehann, 1986). In Japan, the butt rot caused by S. himantioides has been reported in old stands of Chamaecyparis pisifera (Haraguchi et al., 2017, Figure 1a-c) and Abies sachalinensis. Molecular analyses have revealed that S. himantioides includes several cryptic lineages. Kauserud et al. (2004) conducted a phylogenetic analysis based on the internal transcribed spacer (ITS) region and the beta-tubulin (tub) gene and identified two lineages. In a follow-up study, Kauserud et al. (2006) performed a phylogenetic analysis based on four DNA regions [ITS, LSU, tub, and the heat stress protein gene (hsp)] with amplified fragment length polymorphisms (AFLPs) and defined three lineages. This study also showed that these three lineages are mutually incompatible, suggesting that they could be defined as biological species. Carlsen et al. (2011) similarly conducted phylogenetic analyses based on the same four DNA regions with additional samples from different regions around the world, Japan excluded, and concluded that S. himantioides consists of five cryptic lineages (PS1-PS5). In the study of Kauserud et al. (2004), a Japanese isolate used in the phylogenetic analysis based on the ITS region clustered with an
Evaluation of GerminationPromoting Treatments for Toxicodendron vernicifluum Seeds Based on Breaking Physical and Physiological Seed Dormancy. J Jpn For Soc 104: 254-261 The seeds of Toxicodendron vernicifluum are considered to be in a state of combinational dormancy, which is a combination of physical and physiological dormancy. To improve the germination rate of T. vernicifluum seeds, the methods reported to be effective in promoting seed germination were evaluated separately for breaking physical and physiological seed dormancy. The most effective methods for breaking physical dormancy of T. vernicifluum seeds were soaking in concentrated sulfuric acid (H 2 SO 4 ) for 60 to 120 min or partial removal of the endocarp. Water absorption was observed to begin at two locations on the seed after soaking in H 2 SO 4 for 90 min. Cold stratification for 4 to 12 weeks was effective in breaking physiological dormancy of the seeds after soaking in H 2 SO 4 . However, seeds treated with cold stratification after partial removal of endocarp did not germinate. The germination rate of seeds soaked in H 2 SO 4 for 90 min followed by 8 weeks of cold stratification (73.2±2.7%)was significantly higher than that of seeds soaked in H 2 SO 4 or cold stratification alone (0.8±1.0% and 0.4±0.9%, respectively) or no treatment (0.0±0.0), indicating that the combined treatment would be effective for improving T. vernicifluum germination.
Racodium therryanum is a snow mold causing snow blight and seed rot in conifers. The sexual stage of R. therryanum has not been found, however, it has been speculated that Herpotrichia juniperi , which causes brown felt blight, is the sexual stage of R. therryanum . In this study, we conducted phylogenetic analysis using 28S large subunit (LSU) rDNA, 18S small subunit (SSU) rDNA, translation elongation factor 1-alpha ( tef1 ), and RNA polymerase II second largest subunit ( rpb2 ). Four isolates were identified as R. therryanum based on their morphological characteristics; together with two strains of H. juniperi , they composed a clade supported by high bootstrap and Bayesian posterior probability values. Therefore, we conclude that the snow mold previously described as R. therryanum is phylogenetically H. juniperi .
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