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1.
The bee fossil record is fragmentary, making it difficult to accurately estimate the antiquity of bee-mediated pollination. Here, we describe a bee fossil [Melittosphex burmensis (new species), Melittosphecidae (new family)] from Early Cretaceous Burmese amber (approximately 100 million years before the present). The fossil provides insights into the morphology of the earliest bees and provides a new minimum date for the antiquity of bees and bee-mediated pollination.  相似文献   

2.
The fossil record of early feathers has relied on carbonized compressions that lack fine structural detail. Specimens in amber are preserved in greater detail, but they are rare. Late Cretaceous coal-rich strata from western Canada provide the richest and most diverse Mesozoic feather assemblage yet reported from amber. The fossils include primitive structures closely matching the protofeathers of nonavian dinosaurs, offering new insights into their structure and function. Additional derived morphologies confirm that plumage specialized for flight and underwater diving had evolved in Late Cretaceous birds. Because amber preserves feather structure and pigmentation in unmatched detail, these fossils provide novel insights regarding feather evolution.  相似文献   

3.
Ten species of gilled fungi, including the oyster mushroom (Pleurotus ostreatus), have been shown to attack and consume nematodes. It is suggested that these wood-decay fungi utilize the nutrients in their prey to supplement the low levels of nitrogen available in wood. This mode of nutrition is similar in principle to that of carnivorous higher plants.  相似文献   

4.
Dove CJ  Straker LC 《Science (New York, N.Y.)》2012,335(6070):796; author reply 796
McKellar et al. (Reports, 16 September 2011, p. 1619) analyzed Late Cretaceous amber specimens from Canada and identified some filaments as dinosaurian protofeathers. We argue that their analysis and data do not provide sufficient evidence to conclude that such filaments are feather-like structures. Further investigation, including destructive sampling, must be carried out for more convincing conclusions.  相似文献   

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银杏中抗病原真菌的内生真菌的分离筛选   总被引:4,自引:0,他引:4  
从银杏的根、茎、叶中分离到66株内生真菌,研究结果表明,内生真菌数量与银杏树龄有关,树龄越高,其含有的内生真菌数量越多。抑菌试验测定结果表明,29株银杏内生真菌代谢产物对农作物病原真菌具有一定的抑制作用,表明银杏中存在农用活性菌株。  相似文献   

7.
The sedimentary record documenting the northward drift of India (Late Cretaceous to late Early Eocene) has recently provided important clues to the evolution, radiation, and dispersal of mammals. Here, we report a definitive Late Cretaceous (Maastrichtian) archaic ungulate (Kharmerungulatum vanvaleni genus et species nova) from the Deccan volcano-sedimentary sequences exposed near Kisalpuri village in Central India. This find has important implications for the origin and diversification of early ungulates and raises three possible paleobiogeographic scenarios: (i) Archaic ungulates may have been cosmopolitan in distribution. (ii) Kharmerungulatum might be an immigrant from Western Asia. (iii) Archaic ungulates may have originated in India.  相似文献   

8.
High-resolution nuclear magnetic resonance spectra of the carbon nuclei in powdered amber, obtained by using the techniques of magic angle spinning and cross polarization, provide detailed information about the types of carbon functionalities. The entire spectrum of Baltic amber (succinite) is identical for several samples. Baltic amber shows minor differences from Sicilian amber and drastic differences from Burmese, Romanian, and Bohemian ambers.  相似文献   

9.
The discovery of the head capsule of a lepidopterous larva in Canadian amber of the Cretaceous period is the first fossil evidence of Lepidoptera before the Tertiary period.  相似文献   

10.
Glomalean fungi from the Ordovician   总被引:3,自引:0,他引:3  
Fossilized fungal hyphae and spores from the Ordovician of Wisconsin (with an age of about 460 million years) strongly resemble modern arbuscular mycorrhizal fungi (Glomales, Zygomycetes). These fossils indicate that Glomales-like fungi were present at a time when the land flora most likely only consisted of plants on the bryophytic level. Thus, these fungi may have played a crucial role in facilitating the colonization of land by plants, and the fossils support molecular estimates of fungal phylogeny that place the origin of the major groups of terrestrial fungi (Ascomycota, Basidiomycota, and Glomales) around 600 million years ago.  相似文献   

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降解食品中胆固醇的芽孢杆菌T12—1的筛选与应用研究   总被引:9,自引:1,他引:9  
以胆固醇为惟一碳源和能源,从食肉动物肠道的19份样中筛选出有胆固醇降解酶活性的菌株40株;通过比较,选出了在培养液中速度较快和产 酸能较强的4株菌,进而选出胆固醇降解活性较高的菌株T12-1,菌株T12-1发酵上清液应用在蛋白黄胆固醇降解中,作用显著,经动物试验,T12-1菌株在食品中应用安全、无毒。  相似文献   

14.
目的对分离于西藏黑耳中的上升炭角菌进行生物学特性研究。方法对野外采集的黑耳进行组织分离获得菌种,对得到的菌种进行形态和分子生物学鉴定,并进行生物学平板特性培养和木屑菌包驯化栽培。结果鉴定结果显示:所获得的菌株为珍稀药用菌上升炭角菌(Xylaria hypoxylon),其菌丝最适生长因子为果糖、酵母浸膏、pH 6.0和23 ℃。驯化栽培显示:上升炭角菌可在多数阔叶树木屑中生长,菌包A菌丝生长速率为0.87 cm/d,明显高于菌包B。菌包A和菌包B长满菌丝分别需要15和25 d,菌包长满菌丝15~20 d后菌丝体由白变黑,菌包变黑25~35 d后开始出现原基,原基出现10 d后可采收第一潮子实体。结论本研究首次纯人工不覆土驯化栽培出分离于黑耳中的上升炭角菌,并初步探明了其生物学特性,为进一步研究、开发和利用该菌奠定了基础。  相似文献   

15.
地生兰组织培养存在移栽无菌苗成活率低、生长缓慢、开花迟缓、花小甚至不开花等问题,这些与缺少共生的菌根真菌有关。用分离自云南保山、大理等地野生春兰菌根中的内生真菌19个菌株接种春兰组培幼苗,经4.5个月的共生培养,兰苗叶色正常,根系生长良好。测定植物生长量,从长势有明显提高的接菌苗进行重分离及菌根的显微结构观察,确定春兰菌根的形成,并筛选出春兰的有效共生菌根真菌为CLB111,CLB113和MLX102。通过接种处理后春兰苗的鲜重增长率分别为70.6%、70.2%、68.6%,而不接菌的对照仅为45.6%,与对照差异达0.01极显著水平。结果表明这3个菌株均为春兰的菌根真菌的优良菌株.  相似文献   

16.
药用植物内生真菌对3种农作物病原真菌的拮抗作用   总被引:1,自引:0,他引:1  
从药用植物海金沙中筛选抗小麦赤霉菌、番茄早疫霉菌、番茄灰霉菌等植物病原真菌的内生真菌,并进行活性物质检测。结果表明,抗作物病原真菌的药用植物内生真菌种类及其次生代谢产物都具有广泛的生物多样性。80%以上的内生真菌对3种农作物病原真菌具有较强的抗菌活性,其中116①、327和115①号菌株对以上3种霉菌菌丝生长的抑制率分别为99.7%、90.3%和99.1%,对孢子萌发的抑制率分别达到65.8%、55.9%和63.1%。  相似文献   

17.
对槲蕨(Drynaria roosii)的根际真菌和内生真菌进行分离,共获得46株根际真菌,分属2亚门5目6科9属,青霉属、曲霉属、木霉属、镰刀菌属为槲蕨根际真菌优势属;50株内生真菌分属于1亚门4目5科12属,青霉属、曲霉属、木霉属、镰刀菌属为槲蕨内生真菌优势属。槲蕨植物内生真菌及其根际真菌具有丰富的多样性,也具有一定的相关性。  相似文献   

18.
杜仲内生真菌对植物病原真菌的抑菌活性研究   总被引:12,自引:0,他引:12       下载免费PDF全文
为了研究杜仲内生真菌对植物病原真菌的抑制作用,以苹果腐烂病菌(Cytospora sp.)、番茄灰霉病菌(Botrytis cintrea)、西瓜枯萎病菌(Fusarium oxysporum f.sp.niveum)、黄瓜枯萎病菌(Fusarium oxysporium f.sp.cucumerinum)、玉米大斑病菌(Helminthos porium turcicum)和白菜黑斑病菌(Alternaria brassicae)为供试菌种,对49株杜仲(Eucommia ulmoides Oliv)内生真菌及其次生代谢物进行了抑菌活性试验。结果表明,有22株内生菌至少对3种测试菌有抑制作用,9株内生菌对6种测试菌都有抑制作用;11株内生菌的次生代谢产物至少对3种测试菌有抑制作用,4株内生菌的次生代谢产物对6种测试菌都有抑制作用。说明从杜仲内生真菌中可以选择出对植物病原真菌具有良好抑制作用的菌种。  相似文献   

19.
香蕉吸芽苗内生真菌及其根际土壤真菌的鉴定   总被引:1,自引:1,他引:1  
从香蕉吸芽苗的根、叶等组织内分离到11个属的真菌:曲霉属(Aspergillus)、炭疽菌属(Colletotrichum)、镰孢属(Fu-sarium)、胶帚霉属(Gliocladium)、木霉属(Trichoderma)、球二孢属(Botryodiplodia)、丝核菌属(Rhizoctonia)、单格孢属(Ulo-cladium)、散子囊菌属(Eurotium)、直双孢属(D idymaria)和丝葚霉属(Papuladpora)。炭疽菌属为优势菌,占内生真菌分离物总数的50%。从香蕉吸芽苗根际土壤中分离到10个属的真菌:曲霉属、镰孢属、木霉属、丝核菌属、毛霉属(Mucor)、青霉属(Penicillium)、拟青霉属(Paecilomyces)、帚霉属(Scopulariopsis)、球壳孢属(Sphaeropsis)和盾壳霉属(Coniothyrium)。拟青霉属、青霉属和毛霉属为优势菌,分别占根际土壤真菌分离物总数的39.7%、23.8%和17.5%。  相似文献   

20.
薯蓣内生真菌的分离及其抑制植物病原真菌的活性   总被引:1,自引:1,他引:1  
从盾叶薯蓣(Dioscorea zingiberensis C.H.Wright)各部位共分离到50株内生真菌,初步鉴定有19株分属于曲霉属(Aspergillus Micheli ex Fr.)、须壳霉属(Pyrenochaetade Not)、刺孢壳属(Chaetomella Fuckel)、侧孢霉属(Sporotrichum Lk.ex Fr.)、棒束梗霉属(Isaria Pers.ex Fr.)、假黑粉霉属(Coniosporium Lk.ex Fr.)和简梗孢霉属(Chromosporium Corda),其余菌株因不产孢而暂未鉴定。利用生长速率法和孢子萌发法检测到分离于根茎的EDT3、EDT4、EDT5和分离于种子的EDS1、EDS3、EDS4等6株菌株的发酵液对棉花黄萎病菌(Verticillium dahliaeKleb.)等6种植物病原真菌的菌丝生长有抑制作用,其中EDS3和EDS4发酵液的混合液E-y对这6种植物病原真菌的菌丝生长和孢子萌发均有较强的抑制作用。  相似文献   

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