Search

Two Cantharellus species collected from different forest types in northern Iran are reported as new to the country. Phylogenetic analyses of DNA sequences from the internal transcribed spacer 2 (ITS2), nuclear ribosomal large subunit (nLSU), RNA polymerase II (RPB2) and translation elongation factor 1-a gene (TEF1) are presented. Cantharellus alborufescens was collected in slightly acidic soils and C. ferruginascens in moderate acidic soils. Illustrations from fresh material are provided for both species. [ABSTRACT FROM AUTHOR]

Tolerance to flooding is crucial when thinking in promissory species for restoration of ecosystems prone to suffer soil water excess. In this study, we tested the flooding tolerance of two-years-old seedlings of Chestnut-leaved oak (Quercus castaneifoliaC.A.Mey.) to determine whether it can be recommended for use in wetland restoration programs. Seedlings ofQ. castaneifoliawere subjected to three treatments: (1) control (C), (2) flooding for 60 days followed by a 42-day recovery period (F + R) and (3) continuous flooding for 102 days (F). Physiological performance, plant morphological changes and biomass accumulation were assessed. Results showed that, although net photosynthetic rates, stomatal conductance and transpirationdecreased withprolonged flooding, when flood waters were removed, plants were able to recover their physiological activity (49–80% compared to controls). By contrast, when plants were continually flooded, their physiological activity decreased as well as the leaves experienced precocious senescence and wilting. Biomass responses paralleled physiological responses: leaf and root biomass were 42–49% higher under F + R treatment than under continuous flooding, and all plants under the F + R survived. Therefore,Q. castaneifoliaappears as a promising species to be further studied when thinking re-vegetation ofriverine areasand othertemporarily flooded wetlands. [ABSTRACT FROM PUBLISHER]

The charcoal disease agents, Biscogniauxia mediterranea and Obolarina persica are two latent, ascomycetous oak pathogens in the Middle Eastern Zagros forests, where they have devastating effects, particularly during drought. Under greenhouse conditions, we investigated the effects of the two charcoal disease agents individually and in combination with drought on survival, growth, foliar gas-exchange, pigment content, oxidative stress and the antioxidant response of Quercus infectoria and Q. libani, two of the dominant tree species in this region. Commonly, the strongest negative effects emerged in the drought–pathogen interaction treatments. Q. infectoria showed less severe lesions, higher survival, more growth, and less leaf loss than Q. libani under combined biotic and abiotic stress. In both oak species, the combination of pathogen infection and drought resulted in more than 50% reduction in foliar gas-exchange parameters with partial recovery over time in Q. infectoria suggesting a superior defense system. Indeed, enhanced foliar anthocyanin, total soluble protein and glutathione concentrations imply an upregulation of the antioxidant defense system in Q. infectoria under stress while none of these parameters showed a significant treatment response in Q. libani. Consequently, Q. infectoria foliage showed no significant increase in superoxide, lower lipoxygenase activity, and less electrolyte leakage compared to the highly elevated levels seen in Q. libani indicating oxidative damage. Our findings indicate greater drought tolerance and pathogen resilience in Q. infectoria compared to Q. libani. Under future climate scenarios, we therefore expect changes in forest community structure driven by a decline in Q. libani and closely associated organisms. [ABSTRACT FROM AUTHOR]