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1.
Two out of ten Rg-specific antisera tested contain a third antibody specific for the β chain of C4. Analysis of the β chains
of 66 unrelated individuals by sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the epitope detected
is located exclusively on the light (L) β chain. A strong, but incomplete, association between the β chain epitope and the
expression of the Rg: 2 determinant on the α chain of the same protein was also observed. While H (heavy) and L β chains were
not associated with a particular C4 isotype, previously unrecorded associations of β chain polymorphism with theDR locus have been established. 相似文献
2.
3.
The effects of temperature and pH on the growth of yeast species during the fermentation of grape juice 总被引:4,自引:3,他引:1
The effects of temperature and pH on the survival and growth of Saccharomyces cerevisiae, Kloeckera apiculata, Candida stellata, Candida krusei, Candida pulcherrima and Hansenula anomala were examined during mixed culture in grape juice. At 25°C, pH 3.0 and pH 3.5, S. cerevisiae dominated the fermentation and the other species died off before fermentation was completed. Saccharomyces cerevisiae also dominated the fermentation at 20°C but there was increased growth and survival of the other species. At 10°C the fermentation was dominated by the growth of both S. cerevisiae and K. apiculata and there was extended growth and survival of C. stellata and C. krusei. Juices fermented at 10°C exhibited ethanol concentrations between 7.4 and 13.4% and populations of K. apiculata, C. stellata and C. krusei in the range 106 -108 cells/ml. However, these species produced maximum ethanol concentrations in the range 2.7–6.6% when grown as single cultures in grape juice. 相似文献
4.
Steph B. J. Menken Maria Wiebosch-Steeman 《Entomologia Experimentalis et Applicata》1988,49(1-2):141-152
Populations of the parthenogenetic moth Ectoedemia argyropeza (Lepidoptera, Nepticulidae) were studied for their clonal composition. Clones were characterized by 6 polymorphic enzyme loci. In a geographic survey 32 clones were observed among 812 individuals. Two clones were predominant, together they explained over 75% of the total variation. Relationships among clones hinted at a monophyletic origin of the species. Analysis of the life cycle and population structure indicated that E. argyropeza is a very sedentary species, with bottlenecks, drift, and passive migration as important population genetical factors moulding the variation. 相似文献
5.
6.
Stephen B. Heard 《Evolutionary ecology》1994,8(5):493-502
Summary
Wyeomyia smithii mosquitoes distribute their eggs across available oviposition sites (water-holding pitcher plant leaves) of varying quality. I experimentally examined responses to three components of site quality: conspecific larval density, larval density of the pitcher plant midge,Metriocnemus knabi, and pitcher size. Responses to larval treatments were complex and apparently suboptimal. Although mosquito larval performance is better in leaves with fewer conspecific and more midge larvae, females did not lay more eggs in such pitchers. Instead, more eggs were laid in experimental pitchers containing either midge or mosquito larvae, but fewer eggs in pitchers with neither or both. More eggs were laid in larger pitchers, which tend to accumulate more resources and dry out less often. Therefore, although the oviposition decisions made were suboptimal, they were better than random. 相似文献
7.
Timothy A. Heard 《Entomologia Experimentalis et Applicata》1995,76(2):203-209
The oviposition and feeding preferences ofCoelocephalapion aculeatum Fall (Coleoptera: Apionidae), a host specific florivore ofMimosa pigra L. (Mimosaceae), were studied in relation to conspecific damage to its hostplant. Adults ofC. aculeatum cease ovipositing in inflorescences when the egg load reaches a number consistent with the larval carrying capacity of the
inflorescence. The basis for this oviposition deterrence was examined by offering inflorescences damaged by adult feeding
alone, larval feeding alone and a combination of adult feeding and oviposition. Adults preferred to oviposit on inflorescences
which are not damaged by either adult feeding, larval feeding, or oviposition. No evidence for the existence of an oviposition
deterring pheromone (ODP) was found. I suggest that the ability of a single host inflorescence to support the development
of many larvae causes selection for the use of these oviposition deterring cues which can convey more quantitative information
about the level of previous infestation than can ODPs. Adults fed a similar amount on damaged compared to undamaged inflorescences.
These results assisted in the design of host range testing trials and allows predictions to be made about the effectiveness
of this insect as a biological control agent. 相似文献
8.
9.
Aspects of the biology and host range of Sibinia fastigiata Clark (Coleoptera: Curculionidae) were studied to assess its safety for release in Australia as a biological control agent of the weed Mimosa pigra L . (Mimosaceae) . Larvae feed on the seeds and adults on open flowers of their host . Adults oviposit on to immature seeds 3 mm long or less and hence seeds of this length and maturity were used in the host range tests and for rearing . Females are shown to avoid previously attacked seeds enhancing their effectiveness as seed destroyers . Survival of adults was higher when provided with open flowers . The host range was determined using laboratory control - choice oviposition tests on excised plant material and , in the field in the native range , no - choice oviposition tests on living plants , surveys of adults on plants , and breeding of insects from pods of plants of various legume species . The control - choice oviposition tests employed a new design in which the control plant alone was offered to the insects followed by a choice of test plants species . Other than M. pigra, only one plant species was acceptable for oviposition , the closely related M. asperata. Larval development also occurs on M. asperata and this host is occasionally used in the field . This insect was approved for release in March 1997 . 相似文献
10.