Species in the North American clade (NAC) of the Ceratocystis fimbriata complex are mostly weak pathogens that infect native tree hosts through fresh wounds. Isolations from discolored tissue of wounded Tilia americana (basswood) in Iowa and Nebraska yielded a Ceratocystis species that was similar to but distinct from isolates of C. variospora from other hosts. Sequences of 28S rDNA showed that...

The forests in Sardasht area in the West Azarbaijan Province were quantitatively studied in this research. Based on Importance Value Index, in general, two types of forests have been identified: Quercus libani Oliv. in the northern, northeastern and northwestern aspects and Quercus brantii Lindl. in the southern, southeastern and southwestern and eastern aspects. The mean of vegetation crown pe...

Fine roots play a significant role in plant and ecosystem respiration (RS); therefore, understanding factors controlling that process is important both to advancing understanding and potentially in modelling carbon (C) budgets. However, very little is known about the extent to which ectomycorrhizal (ECM) identity may influence RS or the underlying chemistry that may determine those rates. In or...

Three hundred Reticulitermes virginicus (Banks) workers were exposed to three 1-cm3 wood blocks of either Quercus sp. (Red Oak), Populus sp. (Poplar), Pinus sp. (Pine), or Sequoia sp. (Redwood) placed into one of the three bioassay designs (no-, two-, and four-choice) for 21 d. Termite wood consumption was measured by wood weight loss, resistance class, and visual rating. Wood consumption rates...

Powdery mildews are a diverse group of pathogenic fungi that can infect a large number of plant species, including many economically important crops. However, basic and applied research on these devastating diseases has been hampered by the obligate biotrophic lifestyle of the pathogens, which require living host cells for growth and reproduction, and lacking genetic and molecular tools for imp...

11 fungi sampled from Quercus acorns with symptoms of black rot and mummification and from necrotic twigs of Q. petraea were tested for pathogenicity towards seedlings of Q. petraea, Q. robur and Q. rubra in a field experiment. Six months after inoculation, necrosis on the main stem and the subsequent death of Q. robur and Q. petraea plants were observed after inoculation with Aureobasidium pul...

two barley (hordeun vulgare l.) genotypes, radical and cwb, with good to moderate levels of resistance to powdery mildew were crossed with a highly susceptible cultivar (afzal) to determine the genetics of resistance. the parents, fl, f2 and f3 generations of each of the two crosses, were evaluated for powdery mildew resistance in the glasshouse and field at the college of agriculture in karaj ...

The oak red scale insect, Kuwania quercus (Kuwana), was described from specimens collected from the bark of oak trees (Quercus species) in Japan. More recently, the species has been identified from California and China, but Californian specimens differ morphologically from Japanese material and are considered here to be a new species based on both morphological and molecular data. In this paper...