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131.
Very few experimental studies have examined how migration rate affects metapopulation dynamics and stability. We studied the dynamics of replicate laboratory metapopulations of Drosophila under different migration rates. Low migration stabilized metapopulation dynamics, while promoting unstable subpopulation dynamics, by inducing asynchrony among neighboring subpopulations. High migration synchronized subpopulation dynamics, thereby destabilizing the metapopulations. Contrary to some theoretical predictions, increased migration did not affect average population size. Simulations based on a simple non-species-specific population growth model captured most features of the data, which suggests that our results are generalizable. 相似文献
132.
Saurabh Singh Reeta Bhatia Raj Kumar Kanika Sharma Sukanta Dash S. S. Dey 《Euphytica》2018,214(11):207
The Brassica vegetable crops are rich source of important antioxidant compounds having anticancer and health promoting properties. Development of F1 hybrids with better nutritional traits is one of the main breeding objectives in different vegetable crops. Our study is the first report of determining heterotic combinations utilizing cytoplasmic male sterile (CMS) and doubled haploid (DH) inbred lines for antioxidant compounds in snowball cauliflower. Twenty genetically diverse Ogura CMS lines of cauliflower and six DH male fertile inbred lines were crossed to develop 120 F1 hybrids in line?×?tester mating design. The resulting 120 test cross progenies along with 26 parents and 4 standard checks were evaluated in 10?×?15 alpha lattice design with three replications during next cropping season. The CMS lines Ogu33-1A, Ogu122-5A and Ogu119-1A were good general combiner and CMS line Ogu118-6A was poor general combiner for majority of traits. Most of the heterotic hybrids were associated with high positive SCA effects. The proportions of σ2A/D and \(\upsigma^{2}_{\text{gca}} /\upsigma^{2}_{\text{sca}}\) ratios were less than unity in all the cases indicating preponderance of non-additive gene action in the genetic control of all the traits. Highest number of heterotic hybrids with SCA effects in desired positive direction was recorded for ascorbic acid content and phenolic content followed by total carotenoid content. The F1 hybrids with better combining ability and better per se performance could be useful in accumulation of favourable allele for higher concentration of important anti-oxidant compounds. 相似文献
133.
Sumit Kumar Dey Radha Prasanna Devesh Pratap Shiv Dhar Singh Tapan Jyoti Purakayastha 《Archives of Agronomy and Soil Science》2017,63(13):1927-1937
Climate change, as a result of increase in the concentration of greenhouse gases, influences growth and productivity of leguminous crops. A study was carried out to analyse the impacts of elevated carbon dioxide (CO2) and cyanobacterial inoculation on growth, N2 fixation and N availability and uptake in cowpea crop, under different doses of phosphorus. Cowpea crop was grown under ambient (400 µmol mol?1) and elevated (550 ± 20 µmol mol?1) CO2 levels using Free-Air Carbon dioxide Enrichment facility. Elevated CO2 level increased chlorophyll content in leaves, improved nodulation and nitrogen fixation by the crop. Increase in P dose up to 16 mg kg?1 soil enhanced nodule development and N2 fixation under high CO2 condition. Cyanobacterial inoculation increased nodule weight, leghaemoglobin content in nodules and total nitrogenase activity. Although nitrogen concentration in cowpea seeds decreased in high CO2 treatment, higher N uptake was recorded. Under elevated CO2 condition, cyanobacterial inoculation and higher P doses led to enhanced root growth and N2 fixation and availability of soil nitrogen. The study illustrated the synergistic effect of high CO2 and cyanobacterial inoculation in enhancing crop growth and availability of soil N, mediated by biological N2 fixation in cowpea under different levels of P. 相似文献
134.
135.
小麦种子中与抗赤霉病性相关的生化成分分析 总被引:1,自引:0,他引:1
用FPLC方法分析了抗小麦赤霉病程度不同的8个小麦品种种子的水溶性组分。结果表明,所有小麦品种都有1个保留时间为9min的吸收峰(P9),且抗病品种中该吸收峰的高度明显高于感病品种。种子水溶液经过氧化氢温育处理后,P9明显升高,表明有大量的P9生成。因此,推测P9可能是1种与小麦抗赤霉病性相关的生化成分,在小麦抗赤霉病的过程中起作用。 相似文献
136.