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Adaptive evolution of pest insects in response to the introduction of resistant cultivars is well documented and commonly results in virulent (i.e., capable of feeding upon resistant cultivars) insect populations being labeled as distinct biotypes. Phenotypically defined, biotypes frequently remain evolutionarily indistinct, resulting in ineffective application of virulence control measures and shorter durability of resistant cultivars. Here, we utilize an evolutionary framework to discern the genetic relationship between biotypes of the soybean aphid (Aphis glycines, Matsumura). The soybean aphid is invasive in North America and is among the most destructive pests of commercial soybean on the continent. Attempts to breed host‐plant‐resistant soybean have been hampered by the emergence of virulent aphid biotypes that are unaffected by the plant's resistance mechanism(s). Comparative population genetic analysis of virulent and avirulent (i.e., unable to feed on resistant cultivars) biotypes found populations to be genetically indistinguishable across biotype and geographic distance, with high rates of interpopulation immigration and admixture. The lack of genetic distinction between biotypes coupled with elevated genotypic diversity within all populations suggested virulence has a nongenetic‐based or includes a gene complex that is widely distributed throughout soybean aphid populations, which undergo regular dispersal and unimpeded sexual recombination. 相似文献
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BARUNDEB BANERJEE 《Ecological Entomology》1983,8(2):117-123
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- 1 A comparison is made of the number of species of arthropods that inhabit tea plants in young and old habitats. Tea plants of comparable age harbour more species in old habitats than in young habitats.
- 2 In both young and old habitats, there is an initial rise in the number of arthropod species on young tea upto 11 years: in the intermediate phase, i.e. between 12 and 21 years, a sharp decline in species numbers occurs followed by a rapid increase between 22 and 36 years, and a final drop after 36 years. These phases are characterized by sap-feeding mites and insects; leaf eaters and defoliators; stem and root borers; and termites and wood-eating insects respectively.
- 3 Attracting abilities of the plants of different age-groups vary according to their morphological, and physiological attributes depending on their locations in young and old habitats.
- 4 Diverse species of arthropods coexist on tea by developing their own niches in different parts of plants; they apparently avoid interspecific competition by maintaining their numbers at low density.
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Fifteen Brassica species and subspecies, as well as accessions of Arabidopsis thaliana and Eruca sativa, were evaluated for their resistance to the cabbage aphid, Brevicoryne brassicae, in the field and laboratory at Horticulture Research International (HRI) Wellesbourne in 1992. In the laboratory, aphid performance was measured in terms of pre-reproductive period, reproductive period, population increase and insect survival. Using these parameters it was possible to identify brassicas possessing antibiosis resistance. In the field B. brassicae attack was assessed in terms of numbers of insects and it was possible to determine aphid preferences for alighting on different species. High levels of antixenosis and antibiosis resistance were discovered in accessions of Brassica fruticulosa and B. spinescens, in a Brassica juncea breeding line and in Eruca sativa. Partial resistance was found in several other Brassica species. The potential of these various sources as donors of resistance genes to be bred into cultivated brassicas is discussed. 相似文献
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在2013年5-9月,采取5点取样,对云南省昭通温凉玉米种植区及普洱暖热玉米种植区玉米蚜种群动态进行定期、定点、定株的系统调查,明确云南省两种不同生态条件下玉米种植区玉米蚜发生规律及分布特征,为玉米蚜的防治提供理论依据。结果显示:昭通温凉玉米种植区玉米蚜在玉米各生育期均有发生;玉米蚜在抽雄散粉期主要集中在雄穗为害,籽粒建成期以后转移集中在苞叶及雌穗为害;玉米蚜在玉米田始终呈聚集分布,聚集度呈聚集—扩散—聚集趋势。普洱暖热玉米种植区玉米蚜种群数量在玉米进入籽粒建成期后才有所增长;玉米蚜在籽粒建成期以后主要集中在苞叶及雌穗上为害;玉米蚜在玉米田基本呈聚集分布,聚集度始终呈扩散趋势。两地玉米蚜自然种群消长、垂直分布动态,空间动态均具有一定差异,昭通温凉玉米种植区相对更适宜玉米蚜的发生。 相似文献
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N. J. Spiller F. M. Kimmins M. Llewellyn 《Entomologia Experimentalis et Applicata》1985,38(3):293-295
Conclusion Although there have been reports, based on light microscope observations, of damage to mesophyll tissue as a result of stylet penetration, we saw no evidence of this in our wax sections. However, the use of the electron microscope revealed that such damage does occur, and has also shown that both inter- and intracellular penetration routes exist, often within the same track, whereas we had formerly believed the stylet pathways of these aphids to be almost entirely intercellular. The intramural-extracellular route of penetration, characterised by the presence of stylets and or saliva between the cell wall and plasmalemma, requires the greater resolution of electron microscopy and cannot be distinguished in light microscope preparations.Our results suggest that an accurate indication of the stylet pathway cannot be obtained from the use of light microscopy alone, and raise serious doubts about the value of previous studies describing the route of stylet penetration. Light microscopy shows the track only at the tissue level and not at the cellular level. We advocate that all future studies of aphid stylet penetration should utilise both light and electron microscope studies because only the higher resolution of the latter technique will indicate the true stylet pathway and the end points of the tracks. Only then can the feeding site be determined with any precision. 相似文献
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迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2... 相似文献
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Leaf area are very important parameter for the understanding of growth and physiological responses of invasive plant species under different environmental factors. This study was conducted to build non-destructive leaf area model of Wedelia trilobata that were grown in greenhouse. Regression analysis and artificial neural network (ANN) approaches were used for the development of leaf area model with the help of leaf length and width of 262 plants samples. In selection of best method under both techniques, the lower value of mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE) and higher value of R2 were considered. According to the results it was found that ANN have higher value of (R2 = 0.96) and lower value of error (MAE = 0.023, RMSE = 0.379, MAPE = 0.001) than regression analysis (R2 = 0.94, MAE = 0.111, RMSE = 1.798, MAPE = 0.0005). It was concluded that error between predicted and actual value was less under ANN. Therefore, ANN model approach can be used as an alternating method for the estimation of leaf area. Through estimation of leaf area, invasive plant growth can predict under different environment conditions. 相似文献
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蛋白质组学研究是对基因组学研究的重要补充,它是在蛋白质水平定量、动态、整体性研究生物体。该文简要介绍了蛋白质组学的含义,蛋白质组学及植物蛋白质组学产生的科学背景,蛋白质组学的研究内容。概述了非模式植物蛋白质组学的研究进展,主要包括非模式植物个体及群体蛋白质组学,组织和器官蛋白质组学,亚细胞蛋白质组学,响应环境变化的蛋白质组学以及非模式植物生物环境因子的蛋白质组学的研究情况,同时对植物蛋白质组学的发展前景进行了展望。 相似文献
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8种湿地植物不同苗龄植株的表型特征及相关性分析 总被引：1，自引：0，他引：1
对水葱(Scirpus validus Vahl)、香蒲(Typha orientalis Presl)、小香蒲(T.minima Funk.)、再力花(Thalia dealbata Fraser ex Roscoe)、黄菖蒲(Iris pseudacorus Linn.)、灯芯草(Juncus effusus Linn.)、梭鱼草(Pontederia cordata Linn.)和菖蒲(Acorus calamus Linn.)8种多年生湿地植物1年生和3年生植株的地上和地下部分干质量、株高(包括花序高和叶层高)、根长、根数和根粗进行了测定,并对各表型特征指标间以及苗龄与各表型特征指标间的相关性进行了分析。结果显示:8种湿地植物3年生植株的地上和地下部分干质量普遍高于1年生植株;从生长量分配情况看,除小香蒲外,其余种类3年生植株地下部分干质量所占比例均高于1年生植株。多数种类1年生和3年生植株的株高差异较小。从根系特征看,根数小于100、根粗1.0~2.0 cm的植株以1年生为主,而根数大于100、根粗1.0 cm以下和2.0~3.5 cm的植株以3年生为主;根长15~25 cm的植株以1年生所占比例较高(62.5%),而根长25~35 cm的植株1年生和3年生所占比例相等。相关性分析结果表明:1年生植株的地上部分干质量与株高、根长与根粗呈显著正相关(P<0.05),3年生植株的地下部分干质量与根粗也呈显著正相关;但不同苗龄植株的其他表型特征指标间的相关性均不显著。苗龄与植株地下部分干质量呈极显著正相关(P<0.01),但与地上部分干质量、株高、根长、根数和根粗的相关性不显著。总体而言,8种湿地植物3年生植株的表型特征优于1年生植株,更适用于污染水体及退化湿地生态系统的修复。 相似文献
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Marcin Nowicki Logan C. Houston Sarah L. Boggess Anthony S. Aiello Miriam Pay‐Milans Margaret E. Staton Mitsuhiro Hayashida Masahiro Yamanaka Shigetoshi Eda Robert N. Trigiano 《Ecology and evolution》2020,10(15):8299-8312
Cornus kousa (Asian dogwood), an East Asia native tree, is the most economically important species of the dogwood genus, owing to its desirable horticultural traits and ability to hybridize with North America‐native dogwoods. To assess the species genetic diversity and to better inform the ongoing and future breeding efforts, we assembled an herbarium and arboretum collection of 131 noncultivated C. kousa specimens. Genotyping and capillary electrophoresis analyses of our C. kousa collection with the newly developed genic and published nuclear genomic microsatellites permitted assessment of genetic diversity and evolutionary history of the species. Regardless of the microsatellite type used, the study yielded generally similar insights into the C. kousa diversity with subtle differences deriving from and underlining the marker used. The accrued evidence pointed to the species distinct genetic pools related to the plant country of origin. This can be helpful in the development of the commercial cultivars for this important ornamental crop with increased pyramided utility traits. Analyses of the C. kousa evolutionary history using the accrued genotyping datasets pointed to an unsampled ancestor population, possibly now extinct, as per the phylogeography of the region. To our knowledge, there are few studies utilizing the same gDNA collection to compare performance of genomic and genic microsatellites. This is the first detailed report on C. kousa species diversity and evolutionary history inference. 相似文献
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3种地中海橡树在叶脉和气孔性状上的个体发育性变化及其与叶片经济性状的关系我们比较了3个地中海栎属(Quercus)树种幼苗和成龄树的叶脉和气孔性状。之前的研究表明,幼苗的气体交换率往往比成龄树的要高。我们的研究目标是确认叶脉和气孔的性状在整个植物个体发育过程中是否会随着气体交换率的变化而同步改变。我们提出了以下两个备选假设：幼苗比成龄树有着更高的叶脉和气孔密度(假设1);幼苗在维管组织上的投资更少,从而降低了建设成本(假设2)。本研究是在西班牙中西部进行的,我们对每个树种不同生长阶段的植株随机采集了10个样本。我们测量了气孔和叶脉的平均性状(单位叶面积里的气孔大小和数量、叶脉密度、叶脉体积、叶脉到表皮的距离),比叶质量和叶片厚度。研究结果表明,细脉密度和单位面积叶脉体积随着树龄的增加而增加,这似乎与气体交换率方面的个体发育趋势不一致。这种差异支持了我们的假设2,说明植株在幼苗阶段减少对维管组织的投资以最大限度地提高生长速度是其当务之急。幼苗叶片中较大的叶脉间距可以由叶脉到表皮的较短距离所补偿。因此,薄叶片可能是幼苗的一个必要性状,它可以让水分沿较短路径输送到蒸发点,而无需对高成本的维管组织进行大量投资。 相似文献
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《Animal : an international journal of animal bioscience》2015,9(2):267-274
A proteomic approach was used to investigate the effects of the processing method of corn grain and soybean meal on the milk protein expression profile in lactating dairy cows. A total of 12 multiparous Holstein dairy cows were used in a 4×4 Latin square design with a 2×2 factorial arrangement. The primary factors examined were corn (finely ground (FGC) v. steam-flaked (SFC)) and soybean meal (solvent-extracted (SSBM) v. heat-treated (HSBM)), which were used to formulate four diets with the same basal ingredient: 27% FGC and 9% SSBM; 27% SFC and 9% SSBM; 27% FGC and 9% HSBM; and 27% SFC and 9% HSBM. Each period lasted for 21 days. Milk samples were collected on days 18, 19 and 20 of each period. Changes in the milk proteins were assessed by two-dimensional (2D) electrophoresis and ImageMaster 2D Platinum 6.0 software. A total of 13 spots displayed variations in protein spot abundance according to the statistical analysis. These spots were identified by a matrix-assisted laser desorption/ionization-time of flight/time of flight MS. According to the gels, the relative abundance of αs2-casein (CN) fragments was higher in the cows fed the SFC-HSBM than that for SFC-SSBM, whereas β-CN, α-lactalbumin and zinc-alpha-2-glycoprotein fragments were down-regulated in HSBM-fed cows. The relative decrease of β-CN expression was validated by western blot and agreed with the MS data. These results suggested that the method used to process soybean meal modified the synthesis and secretion of milk proteins in lactating dairy cows’ mammary glands. 相似文献
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The persistence of plant populations depends on the ability of individuals to cope with the conditions provided by the community. So far, it is not known whether differences in the diversity and composition of plant communities affect the age structure of plant populations or the expression of stem anatomical traits reflecting investment into plant growth and storage. We analyzed annual growth rings in the secondary xylem and measured stem anatomical traits in individuals from 18 populations of Plantago lanceolata growing in a 12‐year old grassland biodiversity experiment (Jena Experiment). Plant individuals of P. lanceolata were on average older and reproduced later with increasing species richness. Individuals of P. lanceolata were slightly younger and the age distribution within populations skewed to younger individuals in the presence of grasses. The presence of legumes did not affect mean age, but led to a more even age distribution within populations. The width of growth‐related tissues (xylem, phloem, phellem) decreased with increasing species richness. Plant diversity‐effects on storage‐related tissues (pith, cortex) were less consistent, as pith showed increasing width with species richness, while cortex did not change with plant diversity. Our results imply that plant diversity effects on population age structure and the expression of stem anatomical traits of P. lanceolata reflect a tradeoff: growth and turnover is fast at low diversity (younger age, higher allocation to growth‐related tissue, faster generative reproduction), while it is slow at high diversity (older age, higher allocation to storage‐related tissue, later generative reproduction). 相似文献