Ecology of wood‐inhabiting fungi in northern forests of Iran

Wood‐decay fungi are important in forest ecosystems and play an important role in nutrient and carbon recycling. The scope of this research was to identify wood‐inhabiting and wood‐decay macrofungi and determine their ecology. We sampled standing trees and dead wood of oak and hornbeam in the northern forests of Iran, specifically in Mazandaran and Golestan provinces. We assessed the influence of field slope, elevation, site direction and the height of fungal sporocarp position on the tree. The species of wood‐inhabiting and wood‐decay fungi belonged to 11 families: Polyporaceae; Stereaceae; Ganodermataceae; Physalacriaceae; Agaricaceae; Xylariaceae; Pluteaceae; Coprinaceae; Strophariaceae; Pleurotaceae; and Hydnaceae. The most common fungal species identified belonged to the Polyporaceae and Ganodermataceae and predominantly grew on trees growing on a slope of 20%, at an altitude of 700–900 m, 0–3 m from the ground a southwesterly site direction and the northern sides of both tree species. These results indicated that field slope was the most important factor in determining fungal sporocarp abundance.     

Retention behavior of size and aluminum components in handsheets prepared in rosin soap size-alum systems

Handsheets were prepared with rosin soap size and aluminum sulfate under various conditions, and the retention behavior of the rosin size and aluminum components in the handsheets was studied. Pyrolysis-gas chromatography and X-ray fluorescence analysis were used to determine the size and aluminum contents in the handsheets, respectively. When the addition level of rosin soap size varied from 0% to 4% and that of aluminum sulfate was fixed at 2%, the rosin size content increased with the increase in the size addition level, whereas aluminum and calcium contents were roughly constant. Under these conditions, handsheets prepared from fines-free pulp had aluminum contents less than those for the original beaten pulp, probably because the former pulp had a carboxyl content less than that of the latter pulp. Not only the conventional rosin retention mechanism but also mechanism proposed below must exist in the rosin soap size-alum systems. That is, some aluminum compounds originating from aluminum sulfate are adsorbed on pulp fibers immediately after the aluminum sulfate addition. These adsorbed aluminum compounds form cationic sites on pulp fibers, and free rosin acid components with anionic charges are then adsorbed onto the cationic sites of pulp fibers at the wet-end.This research was presented in part at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996     

Artoindonesianin L, a new prenylated flavone with cytotoxic activity from Artocarpus rotunda

A new prenylated flavone, named artoindonesianin L (1), was isolated from Artocarpus rotunda (Hout) Panzer (Moraceae). Its structure was elucidated as on the basis of spectroscopic evidence. Along with this new compound, four known phenolic compounds were also isolated from this plant and identified as artonins M (2) and E (3), cycloartobiloxanthone (4) and artonin O (5). All these compounds showed significant cytotoxicity against murine P388 leukemia cells.     

Basal area growth and mortality of Betula maximowicziana affected by crown dieback in a secondary forest in Hokkaido, northern Japan

Since the late 1990s, decline of B. maximowicziana Regel has been observed in mature secondary forests in various parts of Hokkaido, northern Japan. To develop a method of thinning for large-timber production of B. maximowicziana, we measured basal area growth and the mortality of 217 trees during a four-year period (1999–2003) in a 90-year-old secondary forest with serious tree damage. We analyzed growth and mortality in relation to the degree of crown dieback (DC), symmetric and asymmetric competition from neighbors, and initial tree size. Individual basal area growth decreased with increasing DC, with increasing symmetric (two-sided) competition, and with decreasing initial tree size. During the four-year period, 4.1% of the observed trees died. Logistic regression analysis revealed that mortality rate increased with increasing DC and with increasing symmetric competition. These results suggest that both growth and mortality rates were affected by the same factors (i.e., DC and symmetric competition). We concluded that the resource for which individuals were competing at the study site was underground, most likely water. Modeled growth and mortality rates can be used to improve the management of damaged forests. A management plan for the damaged study site is proposed.     

Effect of aluminum toxicity on flowering time and grain yield on rice genotypes differing in Al-tolerance

Aluminum is a major phytotoxic mineral in the soil at low pH conditions. The effect of aluminum (Al) on root length, flowering time, dry matter production, and grain yield was examined using two tolerant, Pungsan (PS) and Geumgang (GG), and one susceptible, IR36, rice varieties to acid soil. Rice seedlings were subjected to two Al treatments (+Al, 150 μM of Al; −Al, 0 μM of Al) in solution culture, where pH was always adjusted at 3.5. PS and GG showed significantly larger root length than IR36 in +Al at 2 and 8 weeks after the treatment (WAT). Flowering time was delayed 9 days in +Al compared to −Al in GG and PS and 27 days in IR36. Dry matter weight and grain yield of GG and PS were also significantly higher than those of IR36 under +Al. The inhibition of such agronomic traits by Al toxicity was less in Al-tolerant varieties than in a susceptible variety.     

Morphology and heredity of tepal spots in Asiatic and Oriental hybrid lilies (Lilium spp.)

Petal spots constitute an important trait for ornamental flowers, because they generate variation in flower colour and pigmentation patterning. However, only a few reports have described the morphologies and inheritances of petal spots. Two types of spots—raised spots and splatters—appear on the flower tepals of lily (Lilium spp.). Here, we microscopically analysed the morphologies of raised spots and splatters, and compared them with those of petal spots in other species. The raised spots of lily showed an increase in the numbers of parenchymal and epidermal cells, and accumulation of anthocyanin pigments in these cells. We did not observe this type of morphology in the petal spots of rhododendron or Tricyrtis macropoda, indicating that the morphology observed in the raised spots is unique to lily. In the splatters of lily, anthocyanin pigments accumulated only in epidermal cells, and the shape of pigmented cells did not differ from that of unpigmented cells. These features were also observed in spots of T. macropoda. We subsequently investigated the inheritance of raised spots and splatters in an F₁ segregating population. We revealed that F₁ plants with raised spots, splatters, raised spots and splatters, or no spots showed a 1:1:1:1 segregation ratio, indicating that the two types of spots are genetically independent. Such knowledge will facilitate efficient selection during breeding programs focused on the development of cultivars with (or without) spots.     

Effect of lectins on the transport of food factors in caco-2 cell monolayers

The effect of three plant lectins, soybean lectin (SBA), Japanese jack bean lectin (CGA), and wheat germ lectin (WGA), on the transport of various food factors, such as isoflavones, quercetin, dipeptides, and calcium ions, were investigated by use of an intestinal tract model, Caco-2 cell monolayers. The lectins increased the isoflavone transport but had no effect on aglycon transport. SBA increased the transport of quercetin glycosides, whereas CGA and WGA had no effect. The lectins increased the transport of calcium ions but showed no effect on the transport of dipeptides, carnosine, and anserine. Although SBA did not change the transepithelial electrical resistance (TER) value of the Caco-2 cell monolayers, CGA and WGA decreased the TER value. These results indicate that plant lectins affect the transport of food factors in different manners, presumably due to their specific sugar binding activity.     

Caffeoylsophorose in a red vinegar produced through fermentation with purple sweetpotato

Recently, a new red vinegar has been developed via fermentation with the storage root of purple-fleshed sweetpotato, Ipomoea batatas L. cv. Ayamurasaki. The red vinegar had a higher antioxidative activity than white or black vinegars. The red vinegar contained some new components possibly derived from the original purple sweetpotato. A major component was isolated using preparative HPLC, and the chemical structure was determined to be 6-O-(E)-caffeoyl-(2-O-beta-d-glucopyranosyl)-alpha-d-glucopyranose (caffeoylsophorose) by MS and NMR. Because the caffeoylsophorose showed a high antioxidative activity, it plays an important functional role in red vinegar as do anthocyanins and other components. Examination of the mechanism of formation is now in progress.     

Inhibition of phosphorus sorption to goethite, gibbsite, and kaolin by fresh and decomposed organic matter

The direct effects of dissolved organic matter (DOM) on the sorption of orthophosphate onto gibbsite, goethite, and kaolin were examined using a one-point phosphorus sorption index and the linear Tempkin isotherm model. DOM extracted from fresh and decomposed agricultural residues, as well as model organic and humic acids, were used. Changes in the chemical and sorptive characteristics of the DOM in the absence and presence of added orthophosphate (50 mg l⁻¹) were also determined. For residue-derived materials, DOM sorption to all minerals correlated well with percent hydrophobicity, apparent molecular weight, and phenolic acidity in the absence of added orthophosphate. Sorption of DOM to goethite and gibbsite was significantly decreased in the presence of added P. The correlation coefficient values of percent hydrophobicity, apparent molecular weight, and phenolic acidity to sorption also declined in the presence of added P. Thus, the addition of P substantially lowered fractionation of DOM after sorption to goethite and gibbsite. In contrast, few significant P sorption-induced differences were observed in the kaolin system. According to one-point P sorption results, DOM in the form of Aldrich humic acid, oxalate, and decomposed clover and corn residue, significantly inhibited P sorption to goethite at concentrations of 50 and 200 mg total soluble carbon (C_TS l⁻¹). Phosphorus sorption to gibbsite was significantly inhibited by 50 mg C_TS l⁻¹ derived from decomposed corn residue, fresh dairy manure residue, and oxalate solution. At 200 mg C_TS l⁻¹, all DOM solutions were found to inhibit P sorption to gibbsite. This study suggests that DOM inhibition of P sorption depends on the chemical properties of both the sorbent and the DOM itself. In general, DOM from decomposed organic materials inhibited P sorption to a greater extent than did DOM derived from fresh materials. This stronger inhibition highlights the importance of microbial processes in the release of soluble soil P, a key determinant of P availability to plants.     

Characterization of tea cultivated at four different altitudes using 1H NMR analysis coupled with multivariate statistics

The taste of black tea differs according to the different areas in which the tea is grown, even for the same species of tea. A combination of (1)H NMR spectroscopy and partial least-squares discriminate analysis (PLS-DA) was used to assess the quality differences of tea leaves from four cultivation areas with different elevations, RAN > 1800 m, UDA = 1200 m, MEDA = 600 m, and YATA < 300 m, in Sri Lanka. As a result of a statistical analysis, PLS-DA showed a separation between high- and low-quality black teas derived from the four different tea cultivation areas. RAN from the highest elevation showed characteristic trends in the levels of theaflavin and theaflavin 3,3'-digallate that were found only in RAN, and the levels of theanine and caffeine were higher, and the levels of thearubigins, especially thearubigin 3,3'-digallate, were lower in RAN than in UDA, MEDA, and YATA. The structures of these components were determined by 1D and 2D NMR analyses. These results demonstrate that this method can be used to evaluate black tea quality according to the chemical composition or metabolites, which are characteristic of the tea leaves cultivated in four regions with different elevations in Sri Lanka.