共查询到20条相似文献，搜索用时 62 毫秒
1.
棉田多种群优势天敌捕食棉铃虫动态研究 总被引：4，自引：0，他引：4
本文采用二次通用旋转组合设计方法，研究了草间小黑蛛、小花蝽、龟纹瓢虫３种天敌与棉铃虫共存系统的动态捕食量数学模型，对捕食量模型分析可以了解棉铃虫种群密度与天敌复合种群密度之间的关系及对捕食量的影响、各类天敌种群间的交互作用。同时还建立了各类天敌数量增长的子模型。为棉田棉铃虫防治策略提供理论依据。 相似文献
2.
转基因棉田节肢动物群落结构与动态 总被引：6，自引：0，他引：6
2002年在河北省南皮县,以亲本常规棉(石远321)棉田为对照,对转CryC1Ac CpTI基因的双价抗虫棉(SGK321)棉田的节肢动物群落、害虫及其天敌的种群动态进行了系统研究,结果发现:SGK321棉田的功能团种类与常规棉田基本相同,两者节肢动物多样性差异并不显著,物种多样性指数分别为0.975和0.967。但SGK321棉田节肢动物总数量比常规棉田降低了53.9%,其主要原因是基位物种数量显著减少;SGK321棉田与其亲本对照棉田的害虫和捕食性天敌的种类基本相同,但数量差异较大。SGK321对靶标害虫具有很好的抗性,与对照棉田相比,棉铃虫种群数量减少了89.5%。SGK321对棉蚜、棉粉虱、绿盲蝽、小绿叶蝉等非标靶害虫的发生也具有一定抑制作用,其种群数量比对照棉田分别降低了64.5%,15.6%,21.8%和33.7%。SGK321棉田龟纹瓢虫和中华草蛉的种群数量分别比对照增加34.0%和9.1%,但异色瓢虫、小花蝽、异须盲蝽、蚜茧蜂和蜘蛛类等其他主要天敌的数量则分别降低28.6%,6.5%,43.1%,44.7%和14.0%。由此表明:双价抗虫棉SGK321在对棉铃虫具有较好抗性的同时,对棉田主要非标靶害虫也都有一定抑制作用,对某些天敌种类的种群存在不利影响,但对棉田节肢动物多样性动态没有显著影响。 相似文献
3.
为探索直播春棉田害虫与其天敌之间的相互作用和竞争共存机制,采用直接观察法,系统研究了棉田主要害虫和天敌种群的时间动态变化,及其生态位宽度和生态位重叠值。研究结果表明,在直播春棉的不同生育期,棉田害虫和天敌的优势种不同。主要害虫和天敌的发生高峰期多集中在6—7月,而棉蚜高峰期在5月下旬,棉叶蝉高峰期在9月下旬。不同种群的时间生态位不同,害虫中棉盲蝽的生态位宽度最大,其次是棉铃虫,棉叶蝉和棉叶螨的生态位宽度较小;天敌中蜘蛛类天敌的生态位宽度最大,其次是小花蝽,黑襟毛瓢虫的生态位宽度最小。而黑襟毛瓢虫和瓢虫类天敌与棉蚜、棉叶螨生态位重叠度较大。因此,皖西南棉区直播春棉田可利用瓢虫类天敌抑制棉蚜和棉叶螨的危害,保护并利用好蜘蛛类天敌,需重点防治棉盲蝽和棉铃虫。 相似文献
4.
麦套夏播转Bt基因棉田主要害虫及其天敌的发生规律 总被引：68，自引：6，他引：68
１９９７年在田间系统研究了转Ｂｔ基因棉品种中棉所３０（Ｒ９３－６）在麦套种植方式下,对棉田主要害虫及其天敌种群的影响。结果表明,转基因棉对棉铃虫（Ｈｅｌｉｏｔｈｉｓａｒｍｉｇｅｒａ）和棉造桥虫（Ａｎｏｍｉｓｆｌａｖａ）有良好的抗性,发生高峰期百株幼虫数量均显著低于对照品种中棉所１６（早熟品种）,但转基因棉田仍需防治三、四代棉铃虫;和常规棉相比,转基因棉自然控制田和转基因棉综合防治田的棉蚜（Ａｐｈｉｓｇｏｓｙｐｉ）分别增加３３．１％和减少２５．１％、红蜘蛛（Ｔｅｔｒａｎｙｃｈｕｓｃｉｎｎａｂａｒｉｎｕｓ）分别增加１３８．９％和减少１８．５％、棉蓟马（Ｔｈｒｉｐｓｔａｂａｃｉ）分别增加３４６．０％和３１５．３％、白粉虱（Ｔｒｉａｌｅｕｒｏｄｅｓｖａｐｏｒａｒｉｏｒｕｍ）分别增加６３．８％和２９．０％、棉盲蝽（Ｌｙｇｕｓｌｕｃｏｒｕｍ）分别增加５７．１％和减少１８．９％、棉叶蝉（Ｅｍｐｏａｓｃａｂｉｇｕｔｕｌａ）分别增１１．５％和１４．２％、龟纹瓢虫（Ｐｒｏｐｙｌａｅａｊａｐｏｎｉｃａ）分别增加１１．８％和４５．５％、草间小黑蛛（Ｅｒｉｇｏｎｉｄｉｕｍｇｒａｍｉｎｉｃｏｌａ）分别减少３．６％和３．６％、草蛉（Ｃｈ 相似文献
5.
不同类型棉田棉铃虫自然种群生命表比较研究 总被引：6，自引：1，他引：5
1998年在河南安阳植棉区对麦套春棉和平作春棉两种类型棉田二、三代棉铃虫自然种群进行了系统观测,并组建了相应的生命表。麦套春棉和平作春棉二代棉铃虫世代存活率分别为0．092％和0．105％,均低于相应的三代(分别为0．465％和0．450％)。麦套春棉和平作春棉二代棉铃虫自然种群趋势指数Ⅰ分别为0．2946和0．3376,均低于相应第三代(分别为2．9123和2．8318)。麦套春棉二代棉铃虫世代存活率和种群趋势指数均低于同代的平作春棉,而麦套春棉三代棉铃虫世代存活率和种群趋势指数则高于同代的平作春棉。天敌捕食和气候因子是影响两类棉田二、三代棉铃虫自然种群数量变动的关键因素。麦套春棉二代棉铃虫发生期,捕食性天敌发生量较大,棉铃虫自然种群数量较平作春棉减少幅度大;平作春棉三代棉铃虫发生期,棉铃虫自然种群数量较麦套春棉田减少幅度大。 相似文献
6.
为了解决粤北烟区烟草上主要害虫对烟草的危害问题,以烟草上烟蚜、烟青虫和斜纹夜蛾为试验材料,采用田间系统调查方法对上述主要害虫及其天敌种群进行了研究。通过3年连续田间调查,确定广东南雄烟区主要害虫为烟蚜、烟青虫和斜纹夜蛾;烟蚜种群发生规律呈现双峰型,烟田烟青虫成虫和幼虫1年有多个发生峰值,斜纹夜蛾幼虫在烟叶生产季节有2个发生高峰期。烟田优势寄生性天敌有寄生于烟蚜的烟蚜茧蜂和寄生于烟青虫幼虫的棉铃虫齿唇姬蜂及寄生于斜纹夜蛾的侧沟茧蜂;优势捕食性天敌主要有龟纹瓢虫、七星瓢虫、中华草蛉、红彩真猎蝽、烟盲蝽、狭带食蚜蝇和青翅隐翅虫等,其中红彩真猎蝽不仅捕食烟蚜,还捕食烟青虫和斜纹夜蛾幼虫,具有较好的研究价值和应用前景。 相似文献
7.
不同立体种植对棉花主要害虫及其天敌种群消长的影响 总被引：8，自引：0，他引：8
通过种植麦套春棉、麦套春棉播种玉米诱集带、麦套春棉邻近种植玉米三种类型的棉田，以平作春棉为对照。明确了不同类型生态区的主要害虫及天敌种群消长动态。立体种植棉田与平作春棉相比：盛期平均百株黄地老虎为害降低８７．５％；棉叶螨发生早为害重；苗蚜降低９７．８％，差异极显著；伏蚜发生量上升２０２％，差异显著；第二代棉铃虫落卵士降低３３．８％；三、四代棉铃虫落卵量差异不显著。第二代棉铃虫发生期，玉米诱集带百株累计诱集棉铃虫落卵量达１４８４粒，天敌数量最高达８４０头，明显看出种植玉米诱集带对棉铃虫有较好的诱集作用，对天敌有很好的保护和增殖作用。 相似文献
8.
转Bt基因棉田害虫和天敌组成及优势类群时序动态 总被引：5，自引：0，他引：5
在系统调查棉田节肢动物的基础上,就长江流域下游棉区种植转Bt基因棉对棉田害虫和天敌组成、数量以及时序动态的影响进行了分析。结果表明,转Bt基因棉田和常规棉田基本接近,均以棉蚜为害虫优势种,天敌优势种为草蛉、龟纹瓢虫、三突花蛛。按照营养关系分析表明,转Bt基因棉田和常规棉田均以植食性类群在营养层中占绝对优势,其次是捕食性天敌类群,而寄生性天敌较少;刺吸类害虫是植食性害虫的优势功能集团,瓢虫类、蜘蛛类和草蛉类为优势捕食性类群。转Bt基因棉能够显著减少棉田鳞翅目等靶标害虫类群的发生,而对其它非靶标害虫如刺吸类害虫以及棉田天敌发生没有显著影响。 相似文献
9.
淮北棉田节肢动物优势种群时空生态位及天敌对棉蚜控制作用研究 总被引：2，自引：0，他引：2
对淮北棉田节肢动物优势种群组成和时空生态位进行分析,结果表明：棉蚜、烟粉虱、棉叶螨、棉盲蝽、四点亮腹蛛、龟纹瓢虫、T-纹豹蛛、草间小黑蛛、八斑球腹蛛、华姬猎蝽、小花蝽和青翅隐翅虫为优势种群;时间和空间生态位宽度值都是以龟纹瓢虫最大,捕食性天敌优势种群与棉蚜时间生态位重叠值以八斑球腹蛛最大,空间生态位重叠值以T-纹豹蛛最大。综合分析了捕食性天敌优势种群的数量、与棉蚜发生在时间上同步性和空间上同域性以及捕食量大小,建立了捕食性天敌优势种群对棉蚜控制作用模型,以龟纹瓢虫控制作用指数最大,达19.82%。 相似文献
10.
北疆高产棉田棉叶呼吸作用及其与光合作用关系的研究 总被引：7，自引：1，他引：6
在田间自然条件下,测试了北疆高产（２０００ｋｇ·ｈｍ－２）棉田棉叶的呼吸速率（Ｒ）和净光合速率（Ｐｎ）。结果表明,（１）高产棉田花铃期棉叶夜晚呼吸消耗比普通棉田低２６．２％,但白天净光合总量比普通棉田高４６．１％。高产田夜晚呼吸消耗占日间总光合量的８．３９％,低于普通棉田（１５．４７％）。（２）正常条件下,北疆棉田棉叶日间暗呼吸量／总光合量比值约为３０％～４０％。（３）Ｒ随温度的升高而增强,在北疆高产棉区两者的回归关系日间为Ｒ日＝－０．０８８＋０．３８７ＴＬ,ｒ＝０．３０５,ｎ＝２１８,Ｐ＜０．０１;夜晚Ｒ夜＝－１０．８２４＋０．６３３ＴＬ,ｒ＝０．６６４,ｎ＝３４,Ｐ＜０．０１,夜晚气温低是北疆棉花产量高的重要原因之一。（４）棉株叶片呼吸的空间分布随功能叶的转移而变化,花铃期和吐絮期Ｒ表现为生育前期大于生育后期,果枝叶大于主茎叶,中上层主茎叶大于下层叶。（５）棉花单叶呼吸作用具明显的午休现象,其日变化趋势与Ｐｎ变化大致相当,两者相关系数ｒ＝０．９４３＊＊,北疆棉区棉叶的光合午休以及下午Ｐｎ明显低于上午的现象不是呼吸作用造成的。（６）新陆早７号夜晚Ｒ显著高于新陆早４号。（７）土壤缺水使Ｒ和Ｐｎ均降低,且吐絮 相似文献
11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
12.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
13.
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
14.
Richard N. Lester 《Euphytica》1989,44(1-2):125-132
Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected. 相似文献
15.
B. Julier P. Guy C. Castillo-Acuna G. Caubel C. Ecalle M. Esquibet V. Furstoss C. Huyghe C. Lavaud A. Porcheron P. Pracros G. Raynal 《Euphytica》1996,91(2):241-250
Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality. 相似文献
16.
In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,... 相似文献
17.
[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat... 相似文献
18.
不同P-Zn配比对小麦幼苗微量元素营养的影响 总被引：2，自引：0，他引：2
采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应. 相似文献
19.
Summary
Glycine tabacina (Labill.) Benth. is a wild perennial species related to the cultivated soybean, G. max (L.) Merr. It is composed of diploid (2n=40) and tetraploid (2n=80) cytotypes. Currently, to differentiate the cytotypes, plants are grown out in the greenhouse and chromosome counts made on pollen mother cells. It is a laborious and time consuming process. The objective of this study was to determine whether electrophoretic techniques could be utilized to separate the cytotypes. Electrophoretic examination of seven isozyme systems from seed of 67 G. tabacina accessions revealed banding patterns that could be used to differentiate between diploid and tetraploid cytotypes in the species. Among the tetraploid accessions, the number of bands observed were always greater than the diploids. Some tetraploid banding patterns consisted of bands similar to the diploid tabacina and/or additional bands previously identified in other Glycine species. The patterns of isozyme multiplicity and variation in the tetraploid tabacinas suggests more than one mode of origin for the tetraploids. 相似文献
20.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献