丹参红叶病发生的微生态机制

通过对丹参红叶病株与健康株根区土养分含量及根区土和根表土中的微生物区系比较,探索丹参红叶病发生的微生态机制.结果表明:丹参红叶病株叶片中N、P、K、Mn含量均显著低于健康株(P＜0.05);根区土中速效P与健康株根区土无显著差异,速效N、K含量均显著高于健康株根区土(P＜0.05),表明丹参红叶病害发生与P缺乏有关,但植株缺磷不是由于土壤供磷不足所致.丹参红叶病株根区土细菌数量较健康株减少41.3％,真菌和放线菌数量分别较健康株增加156.6％和189.5％,差异均达显著水平(P＜0.05);丹参红叶病株根表土细菌、真菌和放线菌数量变化趋势与根区土—致.在丹参红叶病株根区、根表土壤中,6种优势真菌、4种优势放线菌及2种优势细菌可能为有害微生物.优势真菌为腐皮镰刀菌、露湿漆斑菌、三线镰刀菌、焦曲霉、尖孢镰刀菌及座囊菌;优势放线菌为砖红链霉菌、威威达湖伦茨氏菌、马铃薯疮痂病原链霉菌及山丘链霉菌;优势细菌为阿氏芽孢杆菌及水生细菌.这些优势微生物可能通过影响根系生长及根系对土壤养分吸收引起丹参出现缺磷现象.表明丹参红叶病的发生与丹参根区土和根表土中微生物区系异常密切相关.     

微生物菌剂施用对设施茄子根际土壤养分和细菌群落多样性的影响

[背景]设施茄子连作种植和化学肥料过量施用造成土壤养分失衡、微生物多样性降低、土传病害严重等土壤质量问题,微生物制剂是改善土壤环境质量的一项重要措施。[目的]确定微生物菌剂施用对设施茄子根际土壤养分及细菌群落多样性的影响。[方法]在河北省农林科学院鹿泉大河实验园区,以含有哈茨木霉和巨大芽孢杆菌的微生物菌剂为供试菌剂,采用传统的化学分析方法测定微生物菌剂处理和对照茄子开花期、拉秧期土壤的养分含量;采用稀释涂平板方法测定土壤可培养微生物的数量;采用高通量测序技术测定土壤细菌16S rRNA基因V3-V4区,分析处理和对照土壤的微生物多样性和群落分布规律。[结果]与对照相比,微生物菌剂处理提高了茄子开花期和拉秧期的根际土壤养分含量,拉秧期微生物菌剂处理根际土壤中全氮、碱解氮、有效磷、速效钾含量分别较对照增加13.85%、21.07%、31.51%和55.94%;施用微生物菌剂能够改变土壤可培养微生物的数量和构成,微生物菌剂处理土壤中细菌、真菌、放线菌的数量均显著增加,其中细菌、放线菌在微生物总量中所占比例增加,而真菌的占比则有所降低。微生物菌剂处理能够提高土壤微生物的Shannon指数、降低Simpson指数,ACE指数和Chao1指数差异不显著,表明微生物菌剂能够增加土壤的微生物群落多样性,对微生物群落丰富度影响不明显。从目水平上分析菌剂处理和对照的微生物组成,发现微生物菌剂处理增加了土壤中黄单胞菌目(Xanthomonadales)、红螺菌目(Rhodospirillales)、鞘脂杆菌目(Sphingobacteriales)、芽孢杆菌目(Bacillales)、纤维黏网菌目(Cytophagales)、假单胞菌目(Pseudomonadales)等优势菌目的占比,降低了伯克氏菌目(Burholderiales)、黄杆菌目(Flavobacteriales)等病原菌的占比。微生物菌剂的施入能够促进茄子营养生长,增加茄子的产量,增幅为18.52%。[结论]微生物菌剂作为一种新型环保肥料,具有改善土壤营养状况、增加土壤可培养微生物数量、提高土壤微生物多样性的作用,该结果为微生物菌剂的合理施用提供了科学依据。     

黑曲霉菌剂不同处理对西瓜根际细菌群落及土壤理化性质的影响

【背景】针对我国设施栽培西瓜土传病害发生严重、土壤理化性质劣变等问题,探究微生物菌剂对西瓜根际土壤微生物群落调控及土壤营养改良的作用。【目的】研究黑曲霉菌剂不同处理方式对设施栽培西瓜根际细菌多样性、群落结构及土壤理化性质的影响。【方法】通过高通量测序分析黑曲霉菌剂不同处理对西瓜根际土壤细菌多样性和群落结构的影响;采用分析化学方法测定西瓜根际土壤理化性质并解析驱动西瓜根际细菌群落动态变化的主要理化因素。【结果】黑曲霉菌剂(Y)、氨基寡糖素水剂(A)及黑曲霉菌剂与氨基寡糖素水剂配施(YA)处理,细菌α多样性指数如Chao1、Ace和Shannon等较对照均有所增加;不同处理西瓜根际优势细菌在门水平包括变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteriota)等,其中Proteobacteria相对丰度最高,依次为A (28.26%)>Y (26.74%)>YA (22.61%);黑曲霉菌剂处理西瓜根际土壤芽单胞菌科(Gemmatimonadaceae)和类诺卡氏菌科(Nocardioidaceae)相对丰度较对照明显提高到4.06%和2.43%,氨基寡糖素水剂处理中根际土壤假单胞菌属(Pseudomonas)丰度显著提高(P<0.05),不同处理组微枝形杆菌属(Microvirga)相对丰度较对照均有所提高;黑曲霉菌剂单独或与氨基寡糖素水剂配施处理,西瓜根际土壤全氮、全磷及速效磷含量明显提高;冗余分析(redundancy analysis, RDA)表明,土壤pH、全氮、速效磷、速效钾与西瓜根际细菌群落结构具有显著相关性(P<0.05);Spearman相关性分析表明,根际假单胞菌科相对丰度与土壤全氮、全磷、速效磷、速效钾呈显著或极显著正相关。【结论】黑曲霉菌剂在设施栽培西瓜种植中单独或与氨基寡糖素水剂配施处理,具有提高西瓜根际土壤细菌多样性、增加有益菌群相对丰度、改良土壤理化性质从而提高土壤肥力的作用,该结果为黑曲霉菌剂产品开发及在设施栽培西瓜种植中合理应用提供了科学依据。     

刺槐林魔芋健康高产的土壤微生态机制

通过对刺槐林和农田魔芋健株根区、根表及根外土壤微生物区系及养分含量比较,探索刺槐林魔芋健康高产的土壤微生态机制。结果表明:(1)刺槐林魔芋根外和根表土壤细菌数量分别较农田增加11.8%和588.9%,根区土壤真菌数量较农田显著减少74.4%。(2)刺槐林魔芋根区、根表及根外土壤中的有益优势微生物数量及其比例远高于农田魔芋,有害微生物数量远低于农田魔芋;在刺槐林魔芋根区、根表及根外土壤中,3种优势细菌为放射型根瘤菌(Rhizobium radiobacter)、苏云金芽孢杆菌(Bacillus thuringiensis)及摩氏假单胞菌(Pseudomonas mosselii),其中,根表土壤中放射型根瘤菌及苏云金芽孢杆菌数量分别为农田的25.7倍及13.0倍;2种优势真菌为黒附球菌(Epicoccum nigrum)和疣孢青霉(Penicillium verruculosum),1种优势放线菌为绿淀粉酶链霉菌(Streptomyces viridodiastaticus),其中刺槐林魔芋根表和根外土壤中黒附球菌数量分别较农田高159.2%和120.3%;大量存在于刺槐林下魔芋根外土壤中的疣孢青霉、以及根区、根表、根外土壤中的绿淀粉酶链霉菌在农田魔芋相应部位均未检出。(3)刺槐林下魔芋根外、根区土壤有机质含量分别较农田显著增加167.6%、39.6%,但速效P、K含量较农田分别显著降低85.6%~91.3%、12.4%~13.0%。研究认为,刺槐林魔芋健康高产与其根区、根表及根外土壤中特有的有益优势微生物数量多、有害微生物数量少以及土壤有机质含量高密切相关。     

食细菌线虫对土壤微生物量和微生物群落结构的影响

线虫与微生物的相互作用研究往往是在悉生培养体系 (gnotobiotic microcosm)中进行 ,为了研究在自然或开放土壤条件下土壤线虫与微生物的相互作用 ,作者在开放盆栽体系中接种土壤食细菌线虫 (原小杆线虫 ,Protorhabditis sp) ,研究在小麦不同生育期、在有和无根系作用下食细菌线虫对土壤微生物量和微生物群落结构的影响。结果表明 :接种线虫分别使 SMBC、SMBN、SMBP提高了 2 6 .4 %、32 .9%、2 1.8% ,这种促进作用除个别无根系土和非根际土处理外 ,均达到显著性差异。根际土中的 SMBC、SMBN、SMBP>非根际土 >无根系土。从方差解释比例 v来看 ,SMBN受线虫的影响最大 (v=2 4 % )、其次是 SMBC(v=16 % )、然后是 SMBP(v=12 % ) ,线虫对 SMBC的促进作用在根际土中最突出。接种线虫对土壤细菌、真菌和放线菌的数量有明显的影响。在苗期的无根系土和根际土中 ,接种线虫显著降低了细菌的数量、特别在根际土中尤为突出 ,但在其它处理中却增加了细菌的数量。接种线虫对真菌和放线菌数量的促进作用比对细菌更为明显 ,接种线虫后真菌和放线菌数量的总平均值分别比未接种提高了 4 8.5 %和 6 8.2 % ,而细菌数量的总平均值没有变化。细菌数量与微生物量 C相关散点图表明二者相关性在根际土、非根际土和无根系土中均未     

连作花生田根际土壤优势微生物的分离和鉴定

【目的】从不同连作年限的花生田根际土壤中分离优势微生物并进行鉴定,为研究花生连作后优势微生物的变化奠定基础。【方法】采用土壤稀释分离法从不同连作年限花生根际土壤中分离优势细菌、真菌和放线菌,结合菌株形态特征、培养性状、生理生化特征及16S rDNA序列分析对细菌、放线菌进行鉴定,通过形态特征、培养特征和分子鉴定方法对优势真菌进行鉴定。【结果】从连作花生田根际土壤中分离鉴定出7种优势细菌、7种优势真菌和7种优势放线菌。7种优势细菌分别为Leifsonia xyli、氯酚节杆菌(Arthrobacterchlorophenolicus)、黄色微杆菌(Microbacterium flavescens)、鞘氨醇单胞菌属(Sphingomonas sp.)、巴斯德菌属(Pasteurella sp.)、简单芽孢杆菌(Bacillus simplex)和巨大芽孢杆菌(Bacillus megaterium)。7种优势真菌分别为枝状枝孢菌(Cladosporium cladosporioides)、产紫青霉(Penicillium purpurogenum)、哈茨木霉有性型(Hypocrea lixii)、Exophiala pisciphila、微紫青霉(Penicillium janthinellum)、曲霉(Aspergillus sp.)和大丽轮枝菌(Verticillium dahliae)。7种优势放线菌分别为紫红链霉菌(Streptomyces violaceoruber)、华丽黄链霉菌(Streptomyces flaveus)、Streptomyces panaciterrae、不产色链霉菌(Streptomyces achromogenes)、假浅灰链霉菌(Streptomyces pseudogriseolus)、纤维素链霉菌(Streptomyces cellulosae)和金色链霉菌(Streptomyces aureus)。【结论】本研究是第一次系统的从连作花生根际土中分离鉴定优势微生物,种植花生后根际土壤中优势微生物的种类发生了明显变化,但变化没有规律。     

微生物菌肥对寒地大豆根围土壤细菌群落和产量的影响

通过施用微生物菌肥研究寒地大豆根围土壤细菌多样性和群落组成,缓解因长期施用化肥和农药带来的土壤问题。以大豆合农69为研究对象,设置6个处理：施用大豆专用肥、颗粒肥、复合菌肥、减施15%化肥配施颗粒肥、减施15%化肥配施微生物复合颗粒肥和空白对照,采用高通量测序技术分析大豆荚期根围土壤细菌多样性和群落组成;采用传统统计学方法对株高、荚数、粒数和产量进行统计。门水平放线菌门(Actinobacteria)、变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、绿弯菌门（Chloroflexi）、芽单胞菌门（Gemmatimonadetes）、拟杆菌门（Bacteroidetes）、Patescibacteria和WPS-2为优势菌门。其中减施15%化肥配施颗粒肥处理的优势菌门为变形菌门,其他几个处理的优势菌门为放线菌门;目、科和属水平Gaiellales/Other、酸杆菌目（Acidobacteriales/Other）、Frankiales/Other、鞘脂单胞菌属（Sphingomonas）、嗜酸栖热菌属（Acidothermus）、芽单胞菌属（Gemmatimonas）、罗河杆菌属（Rhodanobacter）、根瘤菌属（Bradyrhizobium）、芽单胞菌科（Gemmatimonadaceae/Other）、链霉菌属（Streptomyces）、念珠菌固体杆菌属（Candidatus Solibacter）、黄杆菌科（Xanthobacteraceae/Other）、褚氏杆菌属（Chujaibacter）、AD3/Other、WPS-2/Other、Saccharimonadales/Other、IMCC26256/Other、Ellin6067、Jatrophihabitans、SC-I-84/Other、芽生球菌属（Blastococcus）、苔藓杆菌目（Bryobacter）、Haliangium、Micropepsaceae/Other、锥杆菌属（Conexibacter）和Elsterales/Other共26个优势属;其中褚氏杆菌属是减施15%化肥配施福尔太微生物颗粒剂处理的优势属,酸杆菌目（Acidobacteriales/other）是空白对照优势目,Gaiellales/Other是其他4种处理的优势属。减施化肥配施福尔太微生物颗粒剂可以有效保证大豆产量,比单施化肥产量提高了4.72%。微生物菌肥的不同施肥方式可以有效改善大豆根围土壤微生物群落构成,减施化肥配施微生物菌肥对寒地大豆具有保产增产作用。     

枯草芽孢杆菌菌剂不同施用方式对甜瓜土壤微生物多样性及生长的影响

甜瓜连作种植和化学肥料过量施用造成了土壤微生态环境失衡、病害严重和产量降低等问题。施用枯草芽孢杆菌菌剂是改善土壤微生态环境、防治土传病害、促进植物生长的一项重要措施。文中以枯草芽孢杆菌为试验菌剂,分析菌剂不同施用方式对设施甜瓜土壤微生物多样性及生长的影响,采用稀释涂布平板方法测定土壤中可培养微生物的数量,采用Illumina Miseq测序技术测定土壤未培养微生物多样性,采用称重法测定甜瓜产量。结果表明,不同甜瓜生育时期,灌根、穴施和蘸根3种菌剂施用方式处理土壤可培养细菌的数量均显著高于对照,灌根、穴施和蘸根处理之间不存在显著差异;3个菌剂施用方式处理开花期土壤真菌数量显著低于对照,但是拉秧期土壤真菌数量差异不显著。比较3种菌剂施用处理中未培养微生物的多样性发现,细菌Shannon指数均高于常规施肥对照,Simpson指数低于对照;蘸根处理的真菌Shannon指数最低,Simpson指数最高。NMDS和聚类分析发现枯草芽孢杆菌菌剂蘸根施用处理对土壤中细菌和真菌菌群影响较大,均独立于一个分枝。微生物菌剂的施用使拟杆菌门 (Bacteroidetes) 的丰度显著降低,放线菌门 (Actinobacteria) 和酸杆菌门 (Acidobacteria) 的丰度显著升高,其中以蘸根处理变化最大。菌剂处理对真菌菌群的多样性影响较小,仅对壶菌门 (Chytridiomycota) 的丰度有显著影响。施用枯草芽孢杆菌菌剂可增加甜瓜的株高、茎粗、叶面积,蘸根处理的促长、增产效果最为显著。枯草芽孢杆菌菌剂作为一种新型环保肥料,具有增加土壤可培养微生物数量、提高土壤微生物多样性、促长增产的作用,该研究为枯草芽孢杆菌菌剂的合理施用提供了科学依据。     

长期不同施肥对番茄根际土壤微生物功能多样性的影响

研究长期定位施肥对番茄根际土壤微生物群落功能多样性的影响,旨在为番茄根际生态过程中的调控提供科学依据和理论指导。以沈阳农业大学长期定位施肥基地的番茄根际土壤为研究对象,采用Biolog-ECO微平板法,分析了11个处理:N(单施氮肥)、K(单施钾肥)、P(单施磷肥)、NP(氮磷肥配施)、NPK(氮磷钾肥配施)、MN(有机肥配施氮肥)、MK(有机肥配施钾肥)、MP(有机肥配施磷肥)、MNP(有机肥配施氮磷肥)、MNPK(有机肥配施氮磷钾肥)、对照CK(不施肥)的土壤微生物群落功能多样性。结果表明:(1)配施有机肥能够显著提高土壤有机质、速效磷、速效钾和碱解氮的含量,氮肥的施入会降低根际土壤的pH,各处理间土壤理化性质的差异显著;(2)配施有机肥可以增强番茄根际土壤微生物对碳源的利用能力,提高微生物群落功能多样性,其中,MNP处理微生物对碳源利用能力最强,微生物活性最高。具体表现为:(1)长期施肥改变了土壤微生物对碳源的利用能力。配施有机肥处理的土壤微生物对6类碳源的总利用能力高于单施化肥处理,以MNP优势最明显;(2)在6类碳源中,氨基酸类碳源利用能力最强,酚酸类碳源利用能力最弱;(3)主成分分析表明,31种碳源对PC1贡献较大的有12种,对PC2贡献较大的有8种;(4)施加肥料的处理的Shannon指数、丰富度指数和优势度指数均高于不施肥的处理,但其均匀度下降。有机肥配施氮磷肥处理的Shannon指数、丰富度指数均显著高于其他处理。综合所有结果,以MNP的施肥较果最佳,能够呈现较高的根际土壤微生物功能多样性。     

沼液与化肥配施对冬小麦根际土壤微生物数量和酶活性的影响

研究了等氮量条件下沼液与化肥配施对冬小麦根际土壤微生物(细菌、真菌和放线菌)数量及土壤酶(脲酶、蛋白酶和过氧化氢酶)活性的影响.结果表明:随着生育期的推进,不同施肥处理小麦根际土壤微生物数量和土壤脲酶、过氧化氢酶活性均呈先降后升的变化趋势,而蛋白酶活性则呈"S"形曲线变化.沼液与化肥合理配施能显著增加根际土壤微生物数量,提高土壤脲酶和蛋白酶活性,以基施50%沼液氮基础上追施50%化学氮处理和基施25%沼液氮基础上追施75%化学氮处理较好,传统尿素处理和单一沼液处理效果均较差.土壤过氧化氢酶活性以基施25%沼液氮基础上追施75%化学氮处理及单施沼液处理在所有测定时期均表现最高,其他处理在各生育时期间差异很大.沼液与尿素配合施用可以提高小麦根际土壤微生物数量和酶活性.     

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.     

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.     

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).     

Theoretical Study of Antagonists and Inhibitors of Mammalian Adenosine Deaminase: I. Adenosine and Its Aza- and Deazaanalogues

Aza- and deazaanalogues of adenosine, including their 1-protonated forms (except for that of 1-deazaadenosine), were studied by computer computation to find a relationship between their molecular structures and substrate properties for the mammalian adenosine deaminase. The atomic charge distribution and maps of the electrostatic potential around their van der Waals molecular surface were calculated for these compounds using the ab initio STO-3G method. The conformational studies are carried out by the MM⁺ method of molecular mechanics. The mechanism that determines the substrate selectivity of mammalian adenosine deaminase is discussed.     

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.     

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).     

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.     

Spatial and temporal patterns of morel fruiting

The biotic and abiotic factors conditioning morel fruit body production are incompletely known. We examined spatial and temporal patterns of Morchella esculenta fruiting over five years in a wooded site in Missouri, USA. Fruiting onset was inversely correlated with spring air and soil temperatures, whereas abundance was positively correlated with rain events (>10 mm) during the 30 d preceding fruiting. The two years with the greatest fruiting had the shortest fruiting seasons (6–7 d). Fruiting season length was positively correlated with soil warming, suggesting that a narrow range of optimum soil temperatures favour the explosive production of fruit bodies. All woody stems of at least 1 cm diam were mapped and stem diameter and crown condition were noted. Morel fruit bodies were significantly closer to stems of Carya spp., Tilia americana and Ulmus americana than predicted by the frequencies of these woody species or their contribution to the total basal area on the site. Although intra-annual clustering of fruit bodies was often observed, inter-annual clustering was not. The spatial pattern of M. esculenta fruiting appears to be associated with vegetation pattern, whereas the onset and abundance of fruiting are determined by the interaction of spring temperatures with availability of supporting precipitation.     

Origin and development of Tool-making behavior in Africa and Asia

Around two-and-a-half million years ago, some hominid populations in Africa began to modify stones and bones in a manner that can be recognized by prehistorians as artifacts, and, by definition, produced the earliest identifiable archaeological record. It is likely that earlier hominid groups also may have had relatively rich tool-using behavioral repertoires similar to that seen in modern chimpanzees (McGrew, 1992), such tools may have been made of perishable materials or minimally modified and thus difficult to identify. This review will focus on the earliest archaeological traces and the spread of hominids out of Africa and into Eurasia.