浙江九龙山国家级自然保护区黑熊活动监测 及其华东地区潜在分布区预测

2017至2020年,在浙江九龙山国家级自然保护区内及周边网格化布设63台Ltl-6210MC红外相机,对区内的黑熊(Ursus thibetanus)及其同域物种进行调查。监测期间,5台红外相机共拍摄到9张黑熊活动照片和6次黑熊活动视频,提取到7次黑熊有效照片。根据本次监测到的黑熊位点与文献记录,共确定华东地区黑熊出现位点14个。基于黑熊栖息地特征选择土地利用和7个生境因子为预测背景,利用物种分布模型预测黑熊在华东地区的潜在分布区。为提高预测的精准度,采用了biomod 2软件包中的10种模型算法,并用真实技能统计值(TSS)和曲线下面积值(AUC)来评估这10种算法,只有当TSS值超过0.8且AUC值大于0.9时,才使用该模型算法预测物种的潜在分布区。结果表明:(1)推测保护区内现存2或3只黑熊;(2)最冷月份最低温(Bio6)和最湿季节降水量(Bio16)是限制黑熊分布的主要环境因子;(3)黑熊在华东地区存在3个主要潜在分布区,即浙–赣潜在分布区、浙–赣–皖潜在分布区和浙–皖潜在分布区,适生区面积约为317km~2。综上所述,这些结果可为加强华东地区黑熊的保护提供一定的资料。     

基于MAXENT模型的古田山保护区黑麂生境适宜性评价

浙江开化古田山国家级自然保护区是黑麂（Muntiacus crinifrons）的集中分布区之一。近年来,保护区内黑麂面临着生境丧失和破碎化的威胁。本研究应用MAXENT模型,结合古田山保护区2014-2017年的红外相机监测数据和主要环境变量数据,对保护区内黑麂生境适宜性的季节变化特征及影响因素进行了评价与分析。结果表明：距阔叶林距离、海拔两个变量对黑麂生境适宜性的季节性变化影响最为显著。古田山保护区不同季节黑麂的适宜生境面积为：春季2086.38 hm²、夏季2608.74 hm²、秋季2502.27 hm²和冬季1746.27 hm²,分别占保护区总面积的25.74%、32.18%、30.87%和21.54%。从空间分布来看,黑麂适宜生境主要分布在保护区的核心区和北部区域。建议加强对保护区的核心区和北部区域自然植被的保护与恢复,以及对保护区人为干扰活动的监督和管理。     

气候变化和人类活动干扰下骆驼刺潜在分布格局变化特征

气候变化和人类活动是影响物种分布的最重要因素。骆驼刺是我国荒漠区的重要建群种,建群种的丧失将对荒漠生态系统产生严重损伤。因此预测气候变化和人类活动影响下骆驼刺适宜生境的变化特点对保护我国荒漠生态系统具有重要的意义。本研究采用61个骆驼分布点数据,和21个环境因子数据,运用最大熵模型（MaxEnt）预测骆驼刺当前在有、无人类活动干扰下的适宜生境分布,对影响其分布的环境因素进行了评估。并预测未来（2021-2040,2041-2060,2061-2080,2081-2100）四条共享社会经济路径（SSP126,SSP245,SSP370,SSP585）情景下,骆驼刺潜在分布区的变化特点。研究结果表明,在无人类活动干扰的情况下,骆驼刺适生区面积达132.29万km²,覆盖我国西北干旱区的大部分面积。年均降水量、最冷季度平均温、平均气温日较差、年均温、温度季节性、降水的季节性和高程被确定为影响骆驼刺潜在分布区的最重要因素。而在加入人类活动强度因素之后,骆驼刺适生区面积显著下降至71.31万km²,且呈现出破碎化状态。此时,年降水量、人类活动强度和高程是影响骆驼刺分布的最重要原因。在未来气候情景下,骆驼刺的适生区将产生一定的扩张。尤其在中高强迫（SSP370）和高强迫（SSP585）情景下,骆驼刺的适生面积将随时间推移产生显著的增加,且这种扩张主要向高纬度和高海拔地区发展。骆驼刺能保留大部分原有生境,仅在内蒙古中西部地区发生少量收缩。在气候变化条件下,骆驼刺能够在西北干旱区生存并扩张,故可将其作为防沙治沙的优良物种进行保护与开发。     

贵州宽阔水自然保护区野生动物红外相机调查初报

为系统掌握宽阔水国家级自然保护区野生动物资源状况,采用公里网格布设红外相机,对宽阔水重点区域大中型兽类和地面活动鸟类进行调查。结果显示：（1）褐胸噪鹛(Garrulax maesi)、蓝歌鸲(Luscinia cyane)、灰翅鸫(Turdus boulboul)、红腿长吻松鼠(Dremomys pyrrhomerus)等4种为该保护区新纪录野生动物;（2）宽阔水拍摄率高的常见种类有红腹锦鸡(Chrysolophus pictus)(1.09)、灰胸竹鸡(Bambusicola thoracica) (0.44)、红腿长吻松鼠(Dremomys pyrrhomerus)(3.16)、野猪(Sus scrofa)(0.69)、小麂(Muntiacus reevesi)(0.49)等。这些常见物种在宽阔水呈现不同的日活动节律。野猪活动频率为早午主副峰型（08:00-09:00为小高峰,11:00-13:30为大高峰）,小麂为晨昏型（09:30-11:30与17:00-19:00两个高峰）,红腿长吻松鼠虽在早08:00-10:00稍显活跃,但整个日间节律高低峰并不明显;灰胸竹鸡日节律呈多高峰,而红腹锦鸡为早晚双峰型（10:00-11:00与16:00-17:00）;（3）宽阔水监测区域内不同生境类型和海拔对物种拍摄率无显著差异。红外相机监测结果能够较为全面地反映出宽阔水保护区鸟兽多样性状况,有利于区域生物多样性编目、保护管理和重要物种生态学研究。     

基于MaxEnt优化模型的闽楠潜在适宜分布预测

闽楠是我国二级保护珍稀濒危植物，不仅是珍贵用材树种，还具有重要的生态价值，预测其潜在适生区变化具有重要意义。采用Enmeval优化包调用MaxEnt模型建立最优模型。基于186条分布记录和9个环境变量模拟闽楠现代2050和2090年代的6个气候情景潜在分布区。综合Jackknife检验、置换重要值和贡献率、多元相似度面和最不相似变量，探讨影响闽楠适生分布区的环境因子，并分析空间变换格局。结果表明：（1）最优模型的参数为：FC=PT，RM=0.5，Maxnnt模型的预测准确度极高，AUC=0.9846±0.0037，现代闽楠潜在适生区的面积为54.32×10⁴km²，闽楠现代高度适生区集中分布在湖南南部和广西东北部；（2）在未来6种气候变化情景下，闽楠潜在适生分布区均有向北扩张的趋势，除2050s-SSP585外，其余情景适生区面积均增加较小，特别是情景2090s-SSP126下，高度适生区将减少40.32%；（3）最干月降水量（bio14）、降水季节性变化（bio15）、最冷月最低温（bio6）、最暖季降水量（bio18）和最暖月最高气温（bio5）是制约闽楠分布格局的主要环境因子；（4）闽楠各个时期的地理分布范围差别较大，说明闽楠对气候变化抗逆性较差，滥砍滥伐、生境破坏和自身繁育问题可能是致濒的重要原因，福建、江西、湖南和广西东北部是闽楠的稳定适生区和未来气候避难区，台湾中部、福建、江西、湖南、湖北西南部和浙南为理想的闽楠人工林引种区，随着气候变暖的日益加剧，粤桂黔三省（区）丧失区面积比较大，并建议对粤桂黔群体进行优先保护。     

浙江清凉峰国家级自然保护区黑麂和小麂潜在适宜栖息地预测及重叠性分析

对保护区内的关键种开展保护工作时,其同域分布相似种的保护研究也具有重要价值。较大地理尺度上看,黑麂的分布区被小麂完全覆盖,如能掌握二者适宜栖息地的重叠状况,揭示其共存机制,将有助于保护策略的制定和整合管理。2017—2020年在浙江清凉峰国家级自然保护区利用红外相机技术分别获得黑麂和小麂的分布位点38个和101个,结合8个环境因子,采用MaxEnt模型对研究区域内黑麂和小麂的潜在适宜栖息地进行了预测和重叠性分析。结果表明：(1)黑麂和小麂潜在适宜栖息地主要位于龙塘山区域西南部,千顷塘区域中部和顺溪坞区域西北部,以及千顷塘区域与龙塘山区域间的山脉和顺溪坞南部山区,二者的潜在适宜栖息地面积分别586.66 km²和661.93 km²,分别占研究区域的36.67%和41.37%。(2)黑麂和小麂的生态重叠指数较高,其D值和I值分别为0.82和0.97,它们的总适宜栖息地重叠面积为435.39 km²,分别占黑麂和小麂总适宜栖息地面积的72.22%、65.78%。(3)黑麂和小麂对环境因子的选择相似,黑麂主要选择海拔较高、离水...     

基于MaxEnt模型的甘肃安西极旱荒漠国家级自然保护区北山羊生境评估

明晰甘肃安西极旱荒漠国家级自然保护区珍稀濒危物种北山羊的分布格局,并阐释气候变化和人类活动对北山羊的影响,对今后北山羊生境管理和物种保护具有重要意义。基于北山羊实测分布点记录和环境变量数据,结合MaxEnt模型和ArcGIS空间分析功能,利用CMIP6的8个气候模式均值预测中度发展路径（SSP2-4.5）下,基准期（1970-2000年）和未来气候（2041-2060年、2081-2100年）变化情景下,甘肃安西极旱荒漠国家级自然保护区北山羊的潜在适生区分布范围及变化,并综合贡献率和置换重要性值对北山羊生境选择关键环境因子进行了分析。研究结果表明：（1） MaxEnt模型的预测精度较高,三种气候条件下ROC曲线下面积（AUC,Area Under Curve）>0.97,且真实技巧统计（TSS,True Skill Statistic）>0.90,模拟结果可靠。（2）影响北山羊生境选择的主要环境因子为气候条件（降水量季节性变异系数和等温性）、海拔和人为干扰（距泉和居名点距离）。水是保护区北山羊生存的最基本要素,气候条件共同控制北山羊生境条件。此外,北山羊习性决定其生境宜选择高海拔和远离人类活动影响地区。（3）基准期保护区北山羊主要分布在北片和南片高海拔山区,面积365.77 km²（占整个保护区的4.31%）,北山羊适生区面积北片>南片、中高等适生区主要位于保护区北片。（4） CMIP6未来气候变化情景下,随着保护区生态环境改善和濒危物种保护措施的实施,北山羊潜在适生区面积呈增加趋势,但是受北山羊近亲繁殖的影响,整体上北山羊数量和适生区面积增加并不显著且有向南部及高海拔地区转移趋势。     

基于MaxEnt模型的雅砻江冬麻豆生境适宜性评价

雅砻江冬麻豆（Salweenia bouffordiana）是近年发现的西南特有冬麻豆属新濒危种,主要分布于四川新龙县的雅砻江河谷。开展其生境适宜性评价及其影响因素分析是对其有效保护的前提和基础。基于2015年8月在雅砻江河谷调查获得的55个分布点,结合24个环境变量数据,利用最大熵模型分析影响雅砻江冬麻豆生境的主要环境因子及其适宜生境预测。结果表明：（1）AUC（曲线下面积）值高于0.9,模型具有较高的准确度,适宜于雅砻江冬麻豆的生境适宜性预测和评估;（2）年均温、最湿月降水、昼夜温差月均值和距河流距离是影响雅砻江冬麻豆生境的最主要环境变量,其最适生境环境变量组合为年均温7.9℃、最湿月降水120-124 mm、昼夜温差月均值13.8℃以及距河流距离33 m;（3）雅砻江冬麻豆的潜在适宜和次适宜生境面积分别约为4.83×10³ hm²和2.37×10⁴ hm²,但仅约7.56×10² hm²的潜在适宜生境和3.28×10³ hm²的潜在次适宜生境位于现有自然保护区管辖范围内。雅砻江冬麻豆的潜在适生区主要沿雅砻江河谷呈狭长的条带状分布,现存区受人类活动影响大,未有生物学地位定级,应尽快确定其生物学保护地位,建立保护小区或社区保护地进行就地保护。     

基于GIS和Maxent模型的赤水河地区濒危植物桫椤生境适宜性评价

桫椤有"蕨类植物之王"赞誉，有"活化石"之称，曾是地球上最繁盛的植物，与恐龙同期。由于地质变迁和气候变化，目前只能在极少数的"避难所"才能寻其踪迹，而赤水河地区是当下桫椤种群较为集中分布的区域。所以，了解桫椤在赤水河地区的适生区分布，对于桫椤种质资源保护、桫椤种群的恢复重建具有重要意义。基于桫椤在赤水河流域的80个桫椤分布点位、20个样地信息和22个环境因子变量，借助ArcGIS运用Maxent模型软件预测了桫椤的潜在地理分布，综合环境因子变量贡献率、刀切法检验和土地利用现状变化对赤水河地区桫椤的生境适宜性进行评价分析，确定桫椤的生境适宜潜在地理分布区域和面积。研究表明：（1）Maxent模型的预测准确度极高，模型的预测结果为"极好"；（2）最暖季的降水（39.65%）、温度日平均范围（18.21%）、温度季节性变化标准差（12.69%）和降水量季节性变异性系数（6.87%）是影响桫椤生长和分布的主导环境因子，累积贡献率达77.42%，可见桫椤在生长过程中对降水、温度的变化较为敏感；（3）模型预测高适生区主要集中在四川（泸州、宜宾、自贡）、重庆、贵州（遵义），在空间上存在明显连续性，从高适生区到不适生区呈辐射状由中心向外围逐渐递减；虽桫椤高适生区面积高达49842 km²，但现状生境破碎化，人为干扰，人工植被较多等的影响会对桫椤种群造成不利影响。综上，赤水河地区桫椤适生生境面积大、连通性好，为本地区的桫椤提供了优质的生存环境，森林的人工抚育可促进桫椤种群的延续。     

基于优化的最大熵模型预测中国高山栎组植物的历史、现状与未来分布变化

气候变化影响着植物物种的地理分布,预测物种潜在适生区对认识其地理分布特征及发挥其生态价值与经济价值具有重要意义。以高山栎组植物为研究对象,运用R语言ENMeval数据包调整调控倍频（RM）和特征组合（FC）优化的最大熵（MaxEnt）模型和ArcGIS软件,基于160条高山栎组植物分布点记录和22个环境因子进行潜在适生区预测,探讨影响其地理分布的主要环境因子,同时预测其在末次间冰期（Last interglacial,LIG）、末次盛冰期（Last glacial maximum,LGM）、全新世中期（Mid Holocene,MH）、当代（Current）、2041-2060年（2050年）和2061-2080年（2070年）3种不同CO₂浓度排放路径下潜在适生区的空间分布格局及其质心变化趋势。结果表明：最优模型参数RM=2.5,FC=LQHPT时,MaxEnt模型复杂度和过拟合程度最低,模型预测准确性极高,AUC=0.960±0.15。综合刀切法贡献率、置换贡献率和单因子响应曲线可知影响其地理分布的主要环境因子是气温季节性变动系数（bio4）、高程（dem）、年降水量（bio12）和等温性（bio3）,其适宜范围分别为435-625、1792-3978m、670-1050mm和41.5-50.3,累计贡献率高达81.6%,其中温度是影响高山栎组植物最重要的环境因子。当前气候条件下,高山栎组植物总适生区面积62.37×10⁴km²,高适生区面积10.47×10⁴km²,占总适生区面积的16.79%,集中分布于川滇横断山地区、滇中高原北部、藏东南以及黔西部分地区。各个时期间高山栎组植物的适生区面积差异较大,当代潜在适生区面积最小且破碎化最严重,可能由于气候变化及人类影响所致。未来各个时期潜在分布区面积均有增大的趋势,但RCP8.5情景下面积相较于其他情景有所降低,表明全球气候变暖背景下不利于高山栎组植物的长期生长。同时,质心分析表明未来气候条件下其分布有向低海拔和低纬度迁移的趋势。     

Nystatin and killer toxin sensitivity of free and immobilizedSaccharomyces cerevisiae

The inhibitory effect of nystatin and killer toxin on the growth of free and covalently-immobilizedSaccharomyces cerevisiae cells was studied. The resistance of immobilized cells to both agents was accompanied by increased amounts of phospholipids and sterols. The possible relationship between these changes in the membrane composition and the transduction of a signal across the cytoplasmic membrane is discussed.     

The hernandez and fernandez genes of Drosophila specify eye and antenna

The formation of different structures in Drosophila depends on the combined activities of selector genes and signaling pathways. For instance, the antenna requires the selector gene homothorax, which distinguishes between the leg and the antenna and can specify distal antenna if expressed ectopically. Similarly, the eye is formed by a group of "eye-specifying" genes, among them eyeless, which can direct eye development ectopically. We report here the characterization of the hernandez and fernandez genes, expressed in the antennal and eye primordia of the eye-antenna imaginal disc. The predicted proteins encoded by these two genes have 27% common amino acids and include a Pipsqueak domain. Reduced expression of either hernandez or fernandez mildly affects antenna and eye development, while the inactivation of both genes partially transforms distal antenna into leg. Ectopic expression of either of the two genes results in two different phenotypes: it can form distal antenna, activating genes like homothorax, spineless, and spalt, and it can promote eye development and activates eyeless. Reciprocally, eyeless can induce hernandez and fernandez expression, and homothorax and spineless can activate both hernandez and fernandez when ectopically expressed. The formation of eye by these genes seems to require Notch signaling, since the induction of ectopic eyes and the activation of eyeless by the hernandez gene are suppressed when the Notch function is compromised. Our results show that the hernandez and fernandez genes are required for antennal and eye development and are also able to specify eye or antenna ectopically.     

Y-chromosome Data and Tribal Affiliations of Allenopithecus and Miopithecus

The phylogeny of Old World monkeys has remained unresolved in part because of a lack of resolution in the Cercopithecinae. Competing morphological hypotheses have had Allen's swamp monkey (Allenopithecus nigroviridis) and the talapoins (Miopithecus spp.) as basal branches of either the tribe Cercopithecini or the tribe Papionini. Previous molecular analyses have not adequately addressed the issue. To better understand the evolutionary history of these primates, we sequenced and subjected to phylogenetic analysis 3.1 kb of 2 loci (TSPY and SRY) from the non-recombining portion of the Y-chromosome. Individuals from the genera Allenopithecus, Miopithecus, Erythrocebus, Chlorocebus, and Cercopithecus were surveyed and their sequences compared with those previously published for the Papionini and Colobinae. The results suggest Allenopithecus and Miopithecus are more closely related to the Cercopithecini than Papionini. Our data also support the hypothesis that within the Cercopithecini, Erythrocebus and Chlorocebus share a close evolutionary relationship, distinct from the other members of the tribe.     

Pericarp structure and phylogeny of theLamiaceae-Verbenaceae-complex

Pericarp structure was investigated in 158 species of the familiesLamiaceae andVerbenaceae. Data from 221 out of 262 genera ofLamiaceae s.l. and a few ofVerbenaceae s.str. were collected in a table. A cladistic analysis was performed on the basis of pericarp characters only. The abandonment of subfam.Pogostemonoideae as a taxonomic unit is considered. Examples of groups given additional support by similarities in pericarp characters are: (1) the gynobasic-styled labiates (subfamiliesPogostemonoideae, Lamioideae, Nepetoideae); (2) aLamioideae-Pogostemonoideae-group; (3)Nepetoideae; (4) aWestringia-Hemigenia-Hemiandra-Microcorys group (in subfam.Chloranthoideae); (5) aLepechinia-Chaunostoma-group (inNepetoideae); (6) aPrunella-Cleonia-group (inNepetoideae).     

Molecular identification and differentiation of Brevibacterium species and strains

Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of Brevibacterium linens, Brevibacterium casei and Brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ARDRA was applied to the 16S rDNA. B. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences. AccI gave genus specific restriction patterns and was used to separate Brevibacterium from Corynebacterium species. The expected species specificity of TaqI applied to B. linens type culture strains, but not to all strains isolated from cheese. By AvaI restriction, B. casei and B. linens were differentiated from B. epidermidis and the orange pigmented Arthrobacter casei, a new species of coryneform bacteria; by XmnI restriction, B. linens and B. epidermidis were differentiated from B. casei. One of 4 B. linens genotypes could not be distinguished from B. casei by this method. Here, the typical orange B. linens pigments were used for classification, which was confirmed by partial sequencing of the 16S rDNA.     

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (1–3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC₅₀'s 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC₅₀'s 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).     

Synthesis and Pharmacological Activity of Betulin Dinicotinate

The assignment of NMR resonances of lupane triterpenoids was refined by the example of 3O,28O-dinicotinoylbetulin, obtained by acylation of betulin. Hepatoprotective, antiulcer, antiinflammatory, reparative, and anti-HIV activities were found for the compound. In addition, it was demonstrated to have immunomodulatory activity, for the first time detected among lupane triterpenoids.     

Effects of carbon concentration and carbon to nitrogen ratio on the growth and sporulation of several biocontrol fungi

Effects of carbon concentration and carbon to nitrogen (C:N) ratio on six biocontrol fungal strains are reported in this paper. All fungal strains had extensive growth on the media supplemented with 6–12 g l⁻¹ carbon and C:N ratios from 10:1 to 80:1, and differed in nutrient requirements for sporulation. Except for the two strains of Paecilomyces lilacinus, all selected fungi attained the highest spore yields at a C:N ratio of 160:1 when the carbon concentration was 12 g l⁻¹ for Metarhizium anisopliae SQZ-1-21, 6 g l⁻¹ for M. anisopliae RS-4-1 and Trichoderma viride TV-1, and 8 g l⁻¹ for Lecanicillium lecanii CA-1-G. The optimal conditions for P. lilacinus sporulation were 8 g l⁻¹ carbon with a C:N ratio of 10:1 for M-14 and 12 g l⁻¹ carbon with a C:N ratio of 20:1 for IPC-P, respectively. The results indicated that the influence of carbon concentration and C:N ratio on fungal growth and sporulation is strain dependent; therefore, consideration for the complexity of nutrient requirements is essential for improving yields of fungal biocontrol agents.     

Development and function of Pisolithus and Scleroderma ectomycorrhizas formed in vivo with Allocasuarina,Casuarina and Eucalyptus

The effect of inoculating seedlings of Eucalyptus grandis, Allocasuarina littoralis and Casuarina equisetifolia with two isolates of Pisolithus and two isolates of Scleroderma from under eucalypts was examined in a glasshouse trial. Ectomycorrhizas formed extensively on Eucalyptus (23–46% fine roots ectomycorrhizal) and Allocasuarina (18–51% fine roots ectomycorrhizal). On Casuarina, the fungi were either unable to colonize the rhizosphere (one isolate of Pisolithus), or sheathed roots, resembling ectomycorrhizas, formed on 1–2% of the fine roots. Colonization of roots by one isolate of Scleroderma resulted in the death of Casuarina seedlings. Inoculation with fungi increased shoot dry weight by up to a factor of 32 (Eucalyptus), 4 (Allocasuarina) and 3 (Casuarina). Ectomycorrhizas formed in associations with Eucalyptus and Allocasuarina had fully differentiated mantles and Hartig nets in which the host and fungal cells were linked by an extensive fibrillar matrix. Sheathed roots in Casuarina lacked a Hartig net, and the epidermis showed a hypersensitive reaction resulting in wall thickening and cell death. The sheaths are described as mantles since the density and arrangement of the hyphae in the sheaths was similar to that in mantles of the eucalypt ectomycorrhizas. The intercellular carbohydrate matrix was not produced in the Casuarina mantle in association with Pisolithus, hence the mantle was not cemented to the root. These structures differ from poorly compatible associations described previously for Pisolithus and Eucalyptus. The anatomical data indicate that ectomycorrhizal assessment based on surface morphological features may be misleading in ecological studies because compatible and incompatible associations may not be distinguishable.     

Filamentous fungi quiescent in seeds and culm nodes of weedy and forage grass species endemic to the Palouse Region of Washington and Idaho

Asymptomatic seeds of forage and weedy grasses from germplasm accessions and from uncultivated sites in eastern Washington and western Idaho were assayed for the presence of quiescent filamentous fungi. Asymptomatic culm nodes of the same species were similarly assayed. The predominant taxa isolated were strains of dematiaceous hyphomycetes, principally strains of Alternaria and Cladosporium. A. infectoria was the species most frequently isolated from seed. A. tenuissima was common and A. alternata was rare. Aspergillus, Penicillium and Fusarium were very rare or absent in stored germplasm. Pathogenic coelomycetes were common in asymptomatic node samples, occasionally present in asymptomatic field seed, but were not detected in germplasm accessions. Previous reports of frequent occurrence of A. alternata in grass seed are probably the results of misidentification of various small-spored Alternarias, especially A. infectoria, as A. alternata.This revised version was published online in October 2005 with corrections to the Cover Date.