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111.
Field experiments on the pollination biology of slickspot peppergrass, Lepidium papilliferum L. (Brassicaceae), a rare species endemic to microsites in sagebrush-steppe habitat in southwestern Idaho, were conducted at 2 sites from May to July 2001. Site KB contained over 10,000 plants, whereas site WG contained less than 150 plants. Insect exclusion experiments revealed that seed production in L. papilliferum is dependent on insect-mediated pollination; median percent seed set dropped from 70% to 2% when insects were excluded from flowers. A total of 25 insect families from 5 orders visited L. papilliferum flowers: 24 families at KB and 11 families at WG. Only 9 families contained more than trace amounts of pollen on their bodies: Hymenoptera-Anthophoridae, Apidae, Colletidae, Halictidae, Sphecidae, Vespidae; Coleoptera-Cerambycidae, Dermestidae; Diptera-Syrphidae. Insects from these families are likely responsible for pollination of L. papilliferum , although some may be of only minor significance due to their infrequent visits to flowers. Two of the 4 most common and pollen-laden insects found at KB, honey bees ( Apis mellifera ) and colletid bees, were absent or rare at WG. Three other pollen-carrying families present at KB, Sphecidae, Vespidae, and Halictidae, were not found at WG. We raise several possible explanations for this disparity in pollinator communities between sites and discuss the importance of pollinator diversity to the long term viability of L. papilliferum . 相似文献
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A. Watson R. Moss R. Parr I. B. Trenholm A. Robertson 《Cellular and molecular life sciences : CMLS》1988,44(3):274-275
Summary This experiment tested whether a cyclic-type population decline can be prevented by removing territorial cock red grouse to keep breeding density below peak levels. The manipulated population did not decline, despite big decreases in food and breeding success, and more parasitic threadworms per bird than on the control. 相似文献
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Fusion between a myogenic cell in the satellite cell position and undamaged adult myofibre segments.
In this report we demonstrate for the first time that differentiating myogenic cells, geographically located between the plasmalemma and external lamina of myofibres in the satellite cell position, can fuse directly with the plasmalemma of undamaged segments of mature myofibres. 相似文献
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Identity of different mutations for deleterious genes 总被引:3,自引:0,他引:3
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L. W. Robertson S. W. Koh S. R. Huff R. K. Malhotra A. Ghosh 《Cellular and molecular life sciences : CMLS》1978,34(8):1020-1022
Summary
Syncephalastrum racemosum ATCC 18192 andMycobacterium rhodochrous ATCC 19067 partially degrade the n-pentyl side chain of cannabidiol, cannabinol, 8-tetrahydrocannabinol and 9-tetrahydrocannabinol. Carboxylic acid and alcohol side chain derivatives are major metabolites.Acknowledgment. The authors wish to express their gratitude to Dr E. H. Fairchild for pmr and mass spectra, Dr R. L. Foltz for gc-ms analysis and to the National Institute on Drug Abuse for financial assistance in the form of a research grant. 相似文献
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J A Robertson 《Nature genetics》2001,28(3):207-209
The clinical use of pharmacogenetic drugs will require that a sample of a patient's DNA be tested before a drug is prescribed. Although pharmacogenetic tests pose fewer risks than genetic tests for disease mutations, they might still reveal personal information that could be used adversely to a patient's interests. Informed consent and privacy of pharmacogenetic test results may be essential in most clinical uses of pharmacogenetic drugs. 相似文献
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