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Within the tribe Stenodermatini the systematics of the complex of species allied with the genus Artibeus has generated several alternative phylogenetic hypotheses. The most recent treatment recognized four genera (Artibeus, Dermanura, Enchisthenes, and Koopmania) and suggested that the most recent common ancestor of these four genera would include the common ancestor of all other currently recognized Stenodermatini genera except Sturnira. To test this hypothesis, we examined an EcoRI-defined nuclear satellite DNA repeat and 402 bp of DNA sequence variation from the mitochondrial cytochrome b gene. Phylogenetic conclusions based on Southern blot analyses, in situ hybridization, and mitochondrial DNA sequence data indicate that Enchisthenes is not closely related to Dermanura, Artibeus, or Koopmania and that Dermanura, Artibeus, and Koopmania shared a common ancestor after diverging from the remainder of the Stenodermatini. If our conclusions are correct, then justification for recognizing Dermanura and Koopmania as generically distinct from Artibeus must be based on the magnitude of difference that distinguishes each rather than on the conclusion that to place them as congeneric with Artibeus creates a paraphyletic taxon.   相似文献   
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本文记述河南省北部太行山区的花蝇科泉种蝇属一新种。模式标本保存在中国科学院上海昆虫研究所。突额泉种蝇Pegohylemyia convexifrons Fan,Chen et Chen,H.,新种(图1-3) :体长6-7mm。头长为头高的0.9倍;眼具疏短微毛;额等于或略宽于前单眼宽,间额黑,突出于侧额,向前扩展成很宽的三角形,色转红褐,侧额上端极狭,向前亦渐宽;间额鬃2对,稍短于单眼鬃,下眶鬃约8-10,在列外侧和列间尚杂有少数细毛,在下眶鬃列内侧的间额边缘每侧有一、二行不整齐共约十余个内倾鬃状毛和细毛;头前面粉被银白,但沿侧额内缘暗色;前额宽约为触角第三节的1.4倍,侧颜向下去明  相似文献   
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植物病原卵菌是一类农业生产上为害巨大的病原物,其分泌大量的RXLR效应分子进入寄主植物细胞并干扰植物免疫系统,以协助病原菌成功侵染。尽管有一小部分RXLR效应分子会被植物识别成为无毒蛋白,但大部分RXLR效应分子则会逃避识别和抑制植物免疫。随着高通量测序和蛋白互作技术的广泛应用,大量RXLR效应分子干扰植物免疫的分子机制已经被揭示。本文综述了RXLR效应分子操纵植物免疫系统的分子策略,探讨了RXLR效应分子与植物免疫互作的研究方向和应用前景。  相似文献   
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范滋德 《动物学研究》1990,11(2):115-119
合夜蝇属Syngamoptero Schnabl,1902隶属蝇科夜蝇亚科Egininae。Eginiclla, Magma和Tertsiuseginia均为本属异名,已知有下列5种,其中2种分布于我国。 1.Syngamoptera amurensis Schnabl,1902 苏联海参威,日本。 2.Syngamoplera brunnescens(Malloch,1925)中国台湾、四川松潘。  相似文献   
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The present study was designed to evaluate cycloheximide as a potential media amendment to prevent fungal overgrowth on selective media for salmonellae enumeration. The objectives were to determine the effect of cycloheximide on Salmonella spp growth rates and to determine the effect of cycloheximide addition on Salmonella enumeration in selective media. The bacteria tested included two strains of Salmonella typhimurium (NO/NA and LT2) and one strain of Salmonella arizonae. All strains were grown in tryptic soy broth containing cycloheximide to determine the effect of cycloheximide on bacterial specific growth rates. The growth rate of all strains grown in tryptic soy broth were not significantly influenced by addition of cycloheximide at concentrations up to 1,000 mg/L. Growth rates of S. typhimurium NO/NA in minimal media were significantly decreased by addition of cycloheximide aerobically (300 mg/L) and anaerobically (600 mg/L). However, S. typhimurium NO/NA populations on brilliant green agar, MacConkey agar, and from selenite cysteine broth and tetrathionate broth were not affected by cycloheximide additions at concentrations up to 1,000 mg/L. Cycloheximide has potential as a fungistat additive for salmonellae selective media.  相似文献   
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Bud formation capacity of callus formed from thin epidermal cell loyers excised from floral branches of Nicotiana tabacum cv. Wise. 38. Subepidermal cells of thin tissue pieces with a few cell layers were capable of forming eitber buds, roots, (lowers or non-organ ogenetic callus. To determine wheiher this calltjs is able to dirferentiate into organs, we transferred it to media inducing eitber flowers, or buds, or roots. In this paper, we study ibe capacity of lbe callus to form buds. In 50% of the cases, the explants (being maintained for I day to 2 years in callus media) can still express the capacity to form buds. This percentage increased with increased agar concentration of the culture media. At the histological level, non-organogenetic callus is characterized by the absence of tracheid differentiation, whereas in the organogenetic callus, iracheids were induced after their transfer into a ‘Bud medium’ and indicate an organogenetic differentiation pattern.  相似文献   
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