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71.
R. S. Medeiros F. S. Ramalho J. C. Zanuncio J. E. Serrão 《Journal of Applied Entomology》2003,127(4):209-213
Abstract: The influence of temperature on life table parameters of Podisus nigrispinus (Dallas) (Het., Pentatomidae) fed with Alabama argillacea (Hübner) (Lep., Noctuidae) larvae was studied. This predator was kept at constant temperatures of 20, 23, 25, 28, 30 and 33±0.2°C, at relative humidity of 60±10% and photoperiod of L : D 14 : 10. Gross (GRR) and net ( R 0 ) reproductive rates of P. nigrispinus ranged from 1.6 to 366.6 and from 0.02 to 189.5 females/female at temperatures of 33 and 28°C, respectively; generation time ( T ) ranged from 33.3 (33°C) to 85.5 (20°C) days; doubling time ( D ) from 0.82 (33°C) to 17.8 (20°C) days; intrinsic rate of increase ( r m ) from −0.13 (33°C) to 0.12 (28°C) per day; and the finite rate of increase ( λ ) from 0.88 (33°C) to 1.12 (28°C) females/female added to the population per day. The ideal age to release P. nigrispinus should be when this predator presents higher reproductive values (VR x ); that is, its adults are about 7 days old, independent of prevailing temperature. Population growth of P. nigrispinus was affected by temperature with maximum numerical response between 28 and 30°C. The negative population growth shown at 33°C may not occur in natural conditions due to milder microclimate in the cotton agroecosystem and due to oscillations of temperature in the course of the day. 相似文献
72.
棉田生态系统能流特征分析 总被引:8,自引:0,他引:8
为丰富生态系统的能流功能理论,开展以此为基础的生态调控,本文采用田间调查与室内测定相结合的方法,系统地测定了棉田初级生产者(棉株)、次级生产者(害虫、天敌)和土壤分解者的能流参数值,分析和比较了以棉株-害虫-天敌相互作用为中心,受人为干扰作用较大的棉田生态系统能流特征。 相似文献
73.
复制型HBV转基因小鼠的遗传与繁育研究 总被引:3,自引:2,他引:1
本文采用类似系祖建系的方法,对复制型HBV转基因小鼠模型的17、21、25三个系列进行了繁育,通过PCR和Southern分子杂交的方法,检测三个系列小鼠尾组织和血清的DNA样品,以确定HBV基因的整合和复制情况。结果表明,HBV基因已稳定地遗传至第五代(F5),且各世代小鼠血清中都存在HBVDNA,此外,整合阳性小鼠的血清中能测出HBVDNA的比率很高,F1代为94.44%(102/108),F2、F3代为95.31%(61/64),故在繁育中可以通过测血清中的HBVDNA来确定小鼠是否整合。 相似文献
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S. C. Bishop 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(3-4):487-491
The use of the sex-determining region Y gene in terminal sire beef cattle breeding was investigated, assuming that fertile transgenic bulls carrying this gene on an autosome can be created. The benefit of these transgenic bulls arises from having an increased proportion of calves with a male phenotype. Two mating strategies utilising the transgenic bulls were devised and compared; the Quota scheme whereby a quota of normal bulls is used alongside the transgenic bulls in a breeding nucleus, and the Bonus scheme in which a phenotypic bonus is assigned to transgenic bulls indicating the added value of their offspring. Bonus and Quota breeding schemes were comparable, in terms of the value of offspring of the bulls, for the first 6 years of selection, after which time the Quota breeding scheme was superior. For time horizons less than 10 years, and large assumed phenotypic superiorities of male calves, breeding schemes with transgenic bulls were superior to traditional breeding schemes without transgenic bulls. If the time horizon was longer, or if the assumed superiority of male calves was small, then traditional breeding schemes were generally superior to those utilising transgenic bulls. Scenarios were observed, however, where transgenic bulls were always superior to normal bulls, in terms of their value as sires. Equations were derived to predict genetic gain and the equilibrium genetic lag between normal and transgenic bulls in Quota breeding schemes. 相似文献
76.
Cotton ovules collected during late September with prevalent night cool temperature (15°C), cultured at 30°C/15°C i.e. cycling temperatures in Beasley and Ting medium had very few epidermal cells showing bulging. Supplementing cultures with guaianolide derivative I (E-13 methyldehydrocostus lactone) promoted fibre initiation. At—1 day preanthesis (DPA), IAA oxidase activity declined in guaianolide-treated cultures but increased during the elongation phase and was enhanced during the secondary wall thickening phase. However, o-diphenol oxidase activity was adversely affected during the fibre initiation phase. The activities of all the other enzymes studied viz. acid invertase, phenylalanine ammonia lyase, -glucosidase and IAA oxidase increased, except -galactosidase, during the later phase in comparison with the controls. The present study indicates that guaianolide derivative I triggers early initiation and promotes fibre elongation by regulatin o-diphenols and IAA-oxidation levels, which in turn check wall loosening. Considerable enhancement in the soluble acid invertase activity by this compound suggests its role in apoplastic sucrose hydrolysis, thereby preventing its accumulation.Abbreviations DPA
days pre anthesis
- DAC
days after culturing
- DAA
days after anthesis 相似文献
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高必需氨基酸转基因马铃薯的研究 总被引:8,自引:0,他引:8
80年代以来,马铃薯遗传转化系统日趋成熟,转基因工程植株已被广泛应用于基础科学研究[1]。作为食物蛋白和能量主要来源的马铃薯,提高其蛋白质含量及质量的遗传工程研究正受到人们的普遍关注[2]。Yang等[2]将旨在改善氨基酸平衡的CAT-HEAAE(氯酶素乙酰转移酶-高含量人体必需氨基酸)融合基因导入马铃薯,获得了Southernblot、Northernblot、Westernblot的证据,但尚缺少氨基酸分析的资料。玉米醇溶蛋白(zein)[3]是一个富含甲硫氨酸的贮存蛋白,它和人工合成的HE… 相似文献