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GERALD A. SCHULTZ MICHAEL E. IRWIN ROBERT M. GOODMAN 《The Annals of applied biology》1983,103(1):87-96
Myzus persicae transmitted soybean mosaic virus (SMV) most efficiently following 30 or 60 s acquisition probes on infected plants. There were no differences in susceptibility to SMV infection of soybean plants 1 to 12 wk old, but symptoms were more severe in plants inoculated when young than when old. Soybeans inoculated between developmental stages R3 and R6 only showed yellowish-brown blotching on one or more leaves. There were no observable differences in the time of appearance or type of symptoms shown by soybean seedlings inoculated either by sap or by aphids; infected plants became acquisition hosts for aphids 5–6 days after inoculation. There was no change in the efficiency with which M. persicae transmitted SMV from source plants up to 18 wk after inoculation. M. persicae transmitted SMV from leaves of field-grown soybeans when plants were inoculated at developmental stages V6, R2, and R3 and tested as sources 57–74 days after inoculation but not from plants inoculated at R5 and tested as sources 14 to 32 days after inoculation. M. persicae acquired SMV from soybean buds, flowers, green bean pods, and unifoliolate, trifoliolate, and senescent leaves. Middle-aged and deformed leaves were better sources of the virus than buds, unfolding and old symptomless leaves. The results are being incorporated into a computer model of SMV epidemiology. 相似文献
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A phylogenetic analysis of the fungus-growing ants (Hymenoptera: Formicidae: Attini) based on morphological characters of the larvae 总被引:4,自引:0,他引:4
A phylogenetic hypothesis of the fungus-growing ants (subfamily Myrmicinae, tribe Attini) is proposed, based on a cladistic analysis utilizing forty-four morphological characters (109 states) of the prepupal worker larva. The fifty-one attine species analysed include representatives of eleven of the twelve currently recognized attine genera, excluding only the monotypic workerless parasite Pseudoatta ; the non-attines include two outgroups (species of the basal myrmicine genera Myrmica and Pogonomyrmex ), two myrmicine species presumed to be distantly related to the attines, and twelve species representing taxa that have been proposed by prior workers as possible sister groups of the Attini. There is strong character support for the monophyly of the Attini and for a sister-group relationship of the Attini and the Neotropical Blepharidatta brasiliensis. The Attini are divided into two distinct lineages, an 'apterostigmoid' clade (containing Apterostigma and Mycocepurus) and an 'attoid' clade (containing all other attine genera except Myrmicocrypta). The attine genus Myrmicocrypta appears to be paraphyletic with respect to these two groups; the species M.buenzlii in particular retains many attine plesiomorphies.
These results indicate that the fungus-growing behaviour had a single evolutionary origin in the ants. They also indicate that mycelium cultivation is plesiomorphic and that yeast cultivation is derived within the Attini, overturning the long-standing assumption that the yeast-growing Cyphomyrmex species are the most primitive Attini. Behavioural and ecological investigations into the origin and evolution of the fungus-growing behaviour might more profitably focus on species in the attine genus Myrmicocrypta , as well as those in the closely related non-attine genera Blepharidatta and Wasmannia. 相似文献
These results indicate that the fungus-growing behaviour had a single evolutionary origin in the ants. They also indicate that mycelium cultivation is plesiomorphic and that yeast cultivation is derived within the Attini, overturning the long-standing assumption that the yeast-growing Cyphomyrmex species are the most primitive Attini. Behavioural and ecological investigations into the origin and evolution of the fungus-growing behaviour might more profitably focus on species in the attine genus Myrmicocrypta , as well as those in the closely related non-attine genera Blepharidatta and Wasmannia. 相似文献
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T. WAYNE SCHULTZ JAMES N. DUMONT LOLA M. KYTE 《The Journal of eukaryotic microbiology》1978,25(4):502-509
SYNOPSIS. Shale oil retort water is obtained by centrifuging the oil/water emulsion produced by oil shale retorting. The ciliate Tetrahymena pyriformis was exposed to retort water; 2, 1, and 0.5% initially increased motility; longer exposures decreased motility. Three, 4, and 5% all decreased motility. Cell lysis was directly related to concentration; after 24 h, population densities were 0, 10, and 25% of controls for 2, 1, and 0.5% retort water, respectively. Oxygen consumption paralleled the motility pattern: at lower concentrations it increased initially but decreased with extended exposures while at higher concentrations it decreased rapidly. The most striking cytologic alteration of cells exposed to the toxicant occurred in the membranes; alterations of mucocysts and glycogen content were also observed, but mitochondrial changes were not. Population growth was affected at much lower concentrations than the other test indices. The growth of test populations reached a plateau at values inversely related to concentration: concentrations <0.4% had no effect on growth rate. 相似文献
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JÜRGEN THIELE OTMAR HONER-SCHMID D
JÜRGEN WAHL GERTRUD KLEEFELD JOACHIM SCHULTZ 《The Journal of eukaryotic microbiology》1980,27(1):118-121
SYNOPSIS A method is described for the axenic mass cultivation of Paramecium tetraurelia strains 51s and 299s. the ciliate is grown in an enriched axenic medium developed by Soldo, Godoy & van Wagtendonk. Under continuous shaking on a rotary shaker, cultures were grown in one-liter Erlenmeyer flasks with 330 ml medium yield cell densities of 32,000 cell/ml and 20,000 cells/ml for strains 299s and 51s respectively. Doubling time is considerably shorter under these conditions than in the conventional static cultures. A 20-liter airlift bioreactor is described in detail which can be used successfully to otain up to 100 g wet weight of Paramecium in a single run; in this reactor the cell density reaches 38,000 cells/ml for strain 299s. and 23,000 cells/ml for 51s. This technic should facilitate the study of minor protein components of the ciliate. 相似文献
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VERONICA KRAPOVICKAS ADRIANA C. MANCUSO CLAUDIA A. MARSICANO NADIA S. DOMNANOVICH CESAR L. SCHULTZ 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2013,46(2):154-169
Krapovickas, V., Mancuso, A.C., Marsicano, C.A., Domnanovich, N.S. & Schultz, C.L. 2013: Large tetrapod burrows from the Middle Triassic of Argentina: a behavioural adaptation to seasonal semi‐arid climate? Lethaia, Vol. 46, pp. 154–169. We report the discovery of large burrow casts in the early Middle Triassic Tarjados Formation, at Talampaya National Park, north‐western Argentina. Facies analysis indicates the burrows are preserved in sandbars deposited by an ephemeral river under semi‐arid and seasonal climatic conditions. The structures are mostly preserved in longitudinal cross‐section and consist of an opening, an inclined tunnel (ramp), and a terminal chamber. The ramp is 8–14 cm in height, up to 130 cm in length and penetrates 49–63 cm bellow the palaeosurface with an inclination of 22°–30°. We studied burrow cast dimensions, overall architectural morphology, surficial marks, and compared them with other large burrows of both invertebrate and vertebrate origin. A tetrapod origin of the burrow casts was established based on: distinctive architecture, and size, which is more than twice the most common size range for large terrestrial invertebrate burrows. Comparison with other Upper Permian and Triassic tetrapod burrows allows us to identify three general morphological groups: (1) simple inclined burrows; (2) helical burrows; and (3) burrow network complexes, representing different behaviours. A study of tetrapod body fossils preserved within other Upper Permian and Triassic burrows shows that the Tarjados structures were most likely produced by non‐mammalian cynodonts. The environmental and climatic context suggests that aridity and seasonality played a fundamental role selecting burrowing behaviour in therapsids and that by the Early–Middle Triassic their burrowing behaviour attained a complexity comparable to modern mammals. □Argentina, behaviour, palaeoclimate, Permo‐Triassic, Tarjados Formation, Tetrapod burrows. 相似文献
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