Biological and inherited characteristics of a newly identified <Emphasis Type="Italic">Lentinula edodes</Emphasis> strain capable of forming a fruiting body without a shift to low temperature

A strain of the basidiomycete Lentinula edodes (Shiitake) was newly identified from the mushroom library of Mori Sangyo Co., Ltd., Japan. This strain, named MIL-LEW-M13-1, is capable of forming the fruiting body on sawdust-based medium without a reduction in temperature. Mating experiments with a monokaryotic mycelium of L. edodes strain that does require low temperature for fruiting–body formation suggest that the unique property of the MIL-LEW-M13-1 strain is a dominant trait that can be inherited by its progeny in a nucleus-dependent manner.     

蓝黄红菇的化学成分

从野生真菌蓝黄红菇Ｒｕｓｓｕｌａ ｃｙａｎｏｘａｎｔｈａ Ｓｃｈａｅｆｆ．Ｆｒ．子实体中分得６个化合物,经光谱法分别鉴定为４个麦角甾醇：５α,８α－ｅｐｉｄｉｏｘｙ－（２２Ｅ,２４Ｒ）－ｅｒｇｏｓｔａ－６,２２－ｄｉｅｎ－３β－ｏｌ １,５α,８α－ｅｐｉｄｉｏｘｙ－（２４Ｓ）－ｅｒｇｏｓｔａ－６－ｅｎ－３β－ｏｌ ２,（２４Ｓ）－ｅｒｇｏｓｔａ－７－ｅｎｅ－３β,５α,６β－ｔｒｉｏｌ ３,     

兴安落叶松的结实及其与短枝年龄结构的关系

继1989年以后,1991年大兴安岭林区兴安落叶松又出现一次结实,结实率平均为63.8％,且结实的林木多出现在过火的林地上。胸径28cm以上的林木结实率可达到80％以上,而且结实量多的林木绝大部分(85％以上)是树冠稀疏的。球果多集中于树冠的中部。短枝年龄结构格局对结实具有重要影响。短枝的数量以1、2年生最多,但结实的短枝主要属于3—7年生的短枝,一次种子丰收年,需要消耗大量的短枝数量,花芽中大部分为雄花,直接用于形成球果的雌花,一般尚不足20％。开花结实成熟年龄短枝的存蓄率愈高,其结实的潜力也愈大,出现种子年的可能性也愈大。     

Sex expression in fruiting male vines of kiwifruit

Summary In three canes on each of five fruiting male kiwifruit vines (A. deliciosa var. deliciosa (A. Chev) Liang and Ferguson), staminate and bisexual flowers were interspersed, so that staminate, bisexual and mixed inflorescences were found. Further variation in inflorescence composition resulted from the abortion of flower buds prior to anthesis. These two sources of variation, in combination, resulted in 19 inflorescence patterns, which varied substantially in frequency among and within vines. Some tendencies were determined. In particular, most of the inflorescences had retained their terminal flower, whereas just over half had retained one or both primary lateral flowers, and in two-thirds of the inflorescences retaining a terminal flower, this was bisexual. The five vines ranged in bisexual flower frequency from 40% to 70%. Phenotypic Gender (P) estimates are given for each vine, based on the frequencies of staminate and bisexual flowers from three canes per vine. Flower development, lability in sex expression and the use of P estimates as part of a selection index in breeding for hermaphrodite kiwifruit cultivars are discussed.     

Spatiotemporal regulation of switching front–rear cell polarity

Bacterial cells are spatiotemporally highly organised with proteins localising dynamically to distinct subcellular regions. Motility in the rod-shaped Myxococcus xanthus cells represents an example of signal-induced spatiotemporal regulation of cell polarity. M. xanthus cells move across surfaces with defined front–rear polarity; occasionally, they invert polarity and, in parallel, reverse direction of movement. The polarity module establishes front–rear polarity between reversals and consists of the Ras-like GTPase MglA and its cognate GEF and GAP, that all localise asymmetrically to the cell poles. The Frz chemosensory system constitutes the polarity inversion module and interfaces with the proteins of the polarity module, thereby triggering their polar repositioning. As a result, the polarity proteins, over time, toggle between the cell poles causing cells to oscillate irregularly. Here, we review recent progress in how front–rear polarity is established by the polarity module and inverted by the Frz system and highlight open questions for future studies.     

Seasonal variation in fleshy fruit use and seed dispersal by the Japanese black bear (<Emphasis Type="Italic">Ursus thibetanus japonicus</Emphasis>)

Fruit use by the Japanese black bear (Ursus thibetanus japonicus) and seed clumping in bear scat were studied in central Japan using fecal analyses. Between May and November 2003 and 2004, the life form and fruit size of plants consumed by bears and the species composition and intactness of seeds contained in scat were examined in five transects (approximately 10 km × 10 m) in broad-leaved deciduous forests. In 2003, scats with seeds were found only in the autumn, when fruiting trees and shrubs were abundant. In 2004, scats with seeds occurred intermittently from the summer, when fruiting plants were rare, up to the autumn. Yearly and seasonal variation in fruit use reflects the opportunistic foraging behavior of Japanese black bears. Seven of the nine plant species detected in scats had medium-sized fruits (6–15 mm width), whereas the other two species had relatively large fruits (20–100 mm width). In total, 14,492 seeds were detected, of which 97.6% were intact; the remainder were damaged. Intact seeds of one or two species were found in each scat. The number of intact seeds per scat ranged from 1 to 5476. Japanese black bears seldom digest ingested seeds, thereby contributing to the seed dispersal of their food plants, including species with fruits that are too large to be swallowed by frugivorous birds.     

A lectin from an edible mushroom Pleurotus ostreatus as a food intake-suppressing substance

In an experiment in which rats were allowed free access to food and water, the rats did not eat the diet containing a mushroom Pleurotus ostreatus even if they were emaciated. A P. ostreatus lectin (POL) was isolated from the mushroom as the food intake-suppression principle. In hemagglutination inhibition assays, Me-αGalNAc was the most potent inhibitor among the monosaccharides tested. Among all the sugars tested, 2′-fucosyllactose (Fucα1→2Galβ1→4Glc) was the strongest inhibitor and its inhibitory potency was five times greater than that of Me-αGalNAc. POL exhibited a binding ability to bovine submaxillary mucin (BSM) and asialo-BSM and the other glycoproteins were inert to the binding. The food intake-suppressing activity of POL was dependent on the dose. The diet containing 0.1% POL caused a 50% decrease in the food intake of rats against the control.     

After the gold rush,or before the flood? Evolutionary morphology of mushroom-forming fungi (Agaricomycetes) in the early 21st century

Mushroom-forming fungi (Agaricomycetes, approx. syn.: Homobasidiomycetes) produce a diverse array of fruiting bodies, ranging from simple crust-like forms to complex, developmentally integrated forms, such as stinkhorns and veiled agarics. The 19th century Friesian system divided the mushroom-forming fungi according to macromorphology. The Friesian taxonomy has long been regarded as artificial, but it continues to influence the language of mycology and perceptions of fungal diversity. Throughout the 20th century, the phylogenetic significance of anatomical features was elucidated, and classifications that departed strongly from the Friesian system were proposed. However, the anatomical studies left many questions and controversies unresolved, due in part to the paucity of characters, as well as the general absence of explicit phylogenetic analyses. Problems in fruiting body evolution were among the first to be addressed when molecular characters became readily accessible in the late 1980s. Today, GenBank contains about 108,000 nucleotide sequences of ‘homobasidiomycetes’, filed under 7300 unique names. Analyses of these data are providing an increasingly detailed and robust view of the phylogeny and the distribution of different fruiting body forms across the 14 major clades that make up the agaricomycetes. However, it would be wrong to suggest that all the important questions about fruiting body evolution have been resolved. Recent studies focusing on resupinate forms suggest that there may still be undetected major clades of agaricomycetes, which could have a significant impact on our estimates of the ancestral forms in this morphologically diverse group. Modern approaches, including comparative phylogenetic analyses and developmental studies, have the potential to yield novel insights into both the macroevolutionary processes and cellular mechanisms of fungal morphological evolution.     

Population structure and fruit production of Pyrus bourgaeana D. are affected by land-use

The Iberian wild pear (Pyrus bourgaeana D.) is a rare, fleshy-fruited tree restricted to dehesas and evergreen sclerophyllous Mediterranean forests in the southwestern Iberian Peninsula. It produces palatable fruits and leaves attractive to different species groups, playing an important trophic role in the ecological networks of Mediterranean ecosystems. However, the intensification in the traditional land-use linked to these areas could threaten the stability of the wild pear populations in the short/medium-term. In order to determine the population dynamics of this relevant species in relation to the land-use history, we selected two populations (southern Spain) subjected to different land-use management, dehesa (D) and abandoned olive grove (AOG). An analysis of 122 adult trees reported an overall density of 0.6 trees ha⁻¹. The tree age was estimated by tree-rings analysis in all adult trees. Dendrometric parameters, reproductive features, and germination rates were also measured. Regeneration was clearly biased, as evidenced by the truncated age structure. A low correlation (R² = 34%) between age and DBH (diameter at breast height) (244 cores analysed) showed that diameter seems not to be a reliable predictor of tree age. Trees from AOG populations had significantly-higher values of DBH, height and crown diameter, but were less productive in terms of fruits and seeds. Nested analysis of variance showed significant variation in fruit production, fruit size, dry mass, water content and seed viability. There were also significant differences in masting. No evidence was found to demonstrate that fruit production, seed viability, or germination rate influence the low natural recruitment of this species. These findings indicate that the traditional agrosilvopastoral practices carried out in the study area for decades, and its subsequent intensification, have strongly influenced the ecological structure of the Iberian wild pear populations at the local scale, which could compromise its stability in the near future.