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1.
黄瓜花叶病毒卫星RNA生防制剂在烟草上的防病作用   总被引:1,自引:0,他引:1  
用人工组装的黄瓜花叶病毒卫星RNA生防制剂在烟草生产品种进行了田间保护试验。由于使用了生防制剂,经处理的烟草发病率降低84.9~86.4%,同时比对照早熟5天,上等烟比率增加151.3~173.5%,平均每亩收入增加43.3~65.7%。另外发现生防制剂能增强烟草对真菌病害的抵抗作用。  相似文献   

2.
2011 ~ 2012 年在内蒙古阿拉善荒漠区,利用复合不育剂EP - 1 (左炔诺孕酮- 炔雌醚),设试验区和对照区,采用春季试验区一次性投饵的方法,对子午沙鼠、小毛足鼠和三趾跳鼠3 种荒漠啮齿动物优势种群的不育控制进行研究。结果表明,不育剂EP - 1 显著降低了优势种群当年的幼体出生率,试验区5 ~ 6 月小毛足鼠幼体比例较对照区显著降低(P < 0. 05),5 ~ 8 月子午沙鼠和6 ~ 8 月三趾跳鼠成体比例分别较对照区显著增加(P < 0. 05),同时显著降低了优势鼠种当年的种群数量,试验区子午沙鼠和小毛足鼠种群在繁殖高峰期的数量均显著低于对照区(P < 0.05),4 ~ 5 月三趾跳鼠种群数量显著低于对照区(P < 0. 05)。次年,试验区5 ~ 7 月子午沙鼠种群成体比例显著高于对照区(P < 0. 05),全年种群数量显著低于对照区(P < 0.05),而三趾跳鼠种群数量与对照区差异并不显著。因此,不育剂EP - 1 对3 种荒漠啮齿动物优势种群数量增长均具有控制作用,尤其对子午沙鼠种群的持续控制效果更加明显。可见,种群在繁殖期年龄结构的变化是影响其种群数量动态的重要因素。  相似文献   

3.
应用灰色关联度(the gray sequence)分析不同防治措施对刚竹毒蛾(Pantana phytlostachysae Chao)种群变动的影响。分析结果表明:生物防治标准地种群变动与对照区相似,虫口较低;化学防治后标准地虫口较对照区为高,种群变动与对照区差异较大。第1代和第3代中各防治区与对照区种群变动最接近的均是白僵菌粉炮,其次是敌敌畏烟剂和油烟剂。第2代则是白僵菌粉炮〉油烟剂〉敌敌畏烟剂。进一步说明不同防治措施在不同环境条件下,干扰自然生态系统的程度不同。  相似文献   

4.
云南主要烟区烟蚜种群解毒酶活力比较   总被引:1,自引:1,他引:0  
通过测定烟蚜Myzus persicae(Sulzer)的α-NA羧酸酯酶、β-NA羧酸酯酶、谷胱甘肽转移酶和乙酰胆碱酯酶的活力,比较了云南5个主要烟区田间烟蚜种群的4种酶的活力频率分布,结果表明,云南5个烟区的烟蚜田间种群的α-NA羧酸酯酶、β-NA羧酸酯酶和乙酰胆碱酯酶的高活力个体均以楚雄和昆明种群较高,昭通种群和丽江种群较低.谷胱甘肽转移酶在5个烟区烟蚜种群间差异不大.  相似文献   

5.
【背景】为评价广聚萤叶甲和豚草卷蛾在豚草发生区大面积释放后对豚草的控制潜力,于2007年和2008年5月底分别在湖南省汨罗大荆和智峰进行了野外释放试验。【方法】释放天敌后,调查豚草的株高、存活率,最后测量其生物量和种子量。【结果】在大荆释放区释放86和120d后,释放区植株高度(61.4和99.0cm)均显著矮于对照区(121.8和129.5em),释放区植株地上茎干重显著小于对照区,但根系干重与对照区无显著差异;释放区植株存活率分别仅为7.3%和0。在智峰释放区,释放12d后,释放区豚草株高和存活率与对照区均无显著差异;但在释放28、44、57d后,释放区株高均显著小于对照区,植株根系和地上茎干重亦显著小于对照区;释放区豚草存活率分别为76.5%、16.5%和0。上述两地,对照区豚草在调查期内的存活率均为100%,释放区的豚草则完全丧失繁殖能力,种子量为0。【结论与意义】在湖南,5月底或6月初,广聚萤叶甲和豚草卷蛾以约每10株6头的密度联合释放,可有效控制豚草。本结果为豚草生物防治技术推广与应用提供了依据。  相似文献   

6.
云南主要烟区烟蚜抗药性的监测   总被引:1,自引:0,他引:1  
采用浸叶法测定了云南省红河弥勒、楚雄东华、昆明寻甸、丽江七河及昭通昭阳共5个烟区的烟蚜Myzuspersicae(Sulzer)种群对7种常用杀虫剂的抗性水平。结果表明,5个烟区烟蚜对甲胺磷均产生了中等或中等程度以上抗性。红河弥勒和昭通昭阳两烟区烟蚜对氧化乐果产生了中等或中等程度以上抗性;楚雄东华、红河弥勒、昭通昭阳和丽江七河烟区烟蚜对硫丹产生了中等或中等程度以上抗性。对其余杀虫剂尚处于低抗以下水平。  相似文献   

7.
使用一定浓度三唑磷农药喷洒小白菜后,测定7d中其体内可溶性蛋白质及抗氧化酶如SOD、CAT、和蛋白酶Mg2+-ATPase、Ca2+-ATPase的含量变化。结果表明.喷药后可溶性蛋白质在第2-4天含量相对于对照组减小,随后呈上升趋势:SOD和CAT在第2~6天均高于对照;而Mg2+-ATPase、Ca2+-ATPase第1~4天与对照相差不大,第5、6天略高于对照;第7天各物质都基本还原到与对照接近或持平。说明三唑磷喷洒后致使植物体内产生了大量氧自由基,进而诱导细胞内防御活性氧自由基毒害的物质产生。为食品卫生检测提供了一个参考标准.  相似文献   

8.
吡虫啉对烟田节肢动物群落的影响研究   总被引:12,自引:8,他引:4  
利用群落参数分析了吡虫啉对烟田节肢动物群落及其各亚群落的影响。结果表明,施药后对烟田节肢动物群落、害虫亚群落的物种数有一定的影响,对天敌昆虫和蜘蛛亚群落物种数的影响不明显。5月23日施药后至6月13日施药区(Ⅱ)和对照区节肢动物群落、害虫亚群落个体数均下降,下降程度施药区大于对照区。6月14日施药后施药区节肢动物群落、害虫亚群落个体数下降,对照区显著上升。两次施药对天敌昆虫和蜘蛛亚群落个体数的影响不明显,施药后一段时间内优势种烟蚜种群个体数量显著下降,使节肢动物群落和害虫亚群落优势集中性下降,多样性指数和稳定性增加。  相似文献   

9.
长脊冠网蝽的生物学特性及防治   总被引:4,自引:0,他引:4  
长脊冠网蝽是檫树的重要害虫,在福建一年发生6~7代,以成虫越冬,翌年4月上树,卵产于叶肉组织中,卵期4~24天,若虫5龄,若虫期9~41天。敌马烟剂、辛硫磷、敌敌畏、敌百虫等药剂对成虫及若虫均有良好毒效。  相似文献   

10.
黄瓜花叶病毒(CMV)危害烟草已成为烟区严重病害之一,如山东烟区CMV引起的烟草病毒病发病率达50%以上。CMV在福建烟区的发病率也达15~30%。上述调查系根据烟草田间症状表现以及温室内不同鉴别寄主的反应和抗性测定得到。为了进一步  相似文献   

11.
采用盆栽试验,研究了施用控释复合肥对烤烟叶片生理特性和氮、磷、钾含量的影响。结果表明:增加控释复合肥的用量能显著提高烤烟叶片生育期的叶绿素、类胡萝卜素(团棵-打顶期)、抗坏血酸(ASA)含量(旺长-成熟期)、超氧化物歧化酶(SOD)活性(团棵-打顶期)和过氧化物酶(POD)活性(旺长-成熟期),同时,烤烟叶片氮、磷、钾含量也呈现上升趋势;相反,增施控释复合肥显著降低了烤烟叶片类胡萝卜素(成熟期)、丙二醛(MDA)、抗坏血酸(团棵期)、谷胱甘肽(GSH)含量(团棵-旺长期)和超氧阴离子自由基(O2·-)产生速率;增施控释复合肥不仅能提高烤烟的抗氧化能力,还能促进对氮、磷、钾营养元素的积累。  相似文献   

12.
唐彪  张锡洲  阳显斌   《生态学杂志》2015,26(7):1977-1984
通过大田小区试验,研究烟蒜轮作、套作对烤烟产量和土壤不同形态磷的影响.结果表明: 烟蒜轮作、套作下烤烟产量和上中等烟比例较烤烟单作显著提高,下部叶成熟期根际土壤有效磷含量分别是烤烟单作的1.3和1.7倍.不同种植方式根际和非根际土壤无机磷组分含量均以O-P和Fe-P含量最高,Ca2-P和Al-P次之,Ca8-P和Ca10 -P含量最低.与烤烟单作和烟蒜套作处理相比,烟蒜轮作在上部叶成熟期根际土壤Ca2-P含量最低,Ca8-P在下部叶成熟期含量最低,Ca10-P含量在中部叶成熟期最低.烟蒜轮作和套作在下部叶成熟期和中部叶成熟期根际土壤Al-P含量分别是烤烟单作的1.6和1.9倍、1.2和1.9倍.烟蒜轮作和套作根际土壤O-P含量均显著低于烤烟单作.烟蒜轮作较烟蒜套作更能活化土壤中难溶的O-P、Ca10-P和高稳性有机磷,提高烤烟产量和中上等烟比例.  相似文献   

13.
We determined the influence of larval host quality of the floating aquatic weed Pistia stratiotes L. (Araceae) on the fecundity and egg distribution of the biological control agent Spodoptera pectinicornis (Hampson) (Lepidoptera: Noctuidae). Different nutritional levels were produced by growing plants with relatively low and high levels of nitrogen, phosphorus and potassium fertilizer. Female and male pupal biomass were significantly greater when the larvae were fed leaves from the high fertilizer plants. Although the fertilizer treatments did not significantly influence total fecundity, there was an indirect effect as adults from larger pupae were more fecund. Regardless of treatment, ovipositing females formed a depression in the leaf surface by removing trichomes into which they deposited the egg masses. Most of the egg masses were laid on the lower leaf surface, on leaf positions 5–8 (counting from the young inner to the outer leaves) and during days 1–2 post-eclosion. Most of the eggs were laid in masses but about 12% were solitary. Females fed the low fertilizer treatment laid a greater proportion (mean ± s.e.) of their eggs as solitary eggs (17.3 ± 3.4% of total eggs) than did females fed the high fertilizer treatment (8.3 ± 2.3% of total eggs). The increased percentage of solitary eggs laid by the females from the low quality larval diet may be an adaptive response to decrease competition among the progeny.  相似文献   

14.
Alternaria longipes (Ell. &Ev.) Mason survived on autoclaved maize stems for 6 months without losing its pathogenicity, but rapidly lost viability on non-autoclaved stems and could not be re-isolated 4 months after inoculation. In laboratory tests it infected both living and dead maize leaves. Some Alternaria isolates from non-solanaceous hosts infected tobacco leaves kept at high humidities for 10 days after inoculation, but not when this incubation period was reduced to 48 h. In the field, perennation on plants other than tobacco is unlikely to be important as a source of inoculum. Pathogenicity of Alternaria isolates was maintained from one season to the next when stored as conidia in sterile soil, or as dried, infected tobacco leaves; some isolates maintained on agar slopes under oil were still pathogenic after 5 years. Alternaria conidia collected from the surface of tobacco seedlings, and isolates from apparently healthy seedling leaves were pathogenic to mature tobacco. In the field conidia were detected on tobacco leaves soon after these emerged, and epiphytic colonies were occasionally found well in advance of symptoms. Many latent infections were also detected up to 5 weeks in advance of symptoms. Visual development of latent infections closely coincided with the end of leaf expansion.  相似文献   

15.
品种、种子大小和施肥对冬小麦生物学特性的影响   总被引:4,自引:0,他引:4  
吉春容  李世清  李生秀 《生态学报》2007,27(6):2498-2506
试验设不同年代冬小麦品种、粒重、播种方式和施肥等4个因子,品种选用白芒麦(20世纪60年代)、咸农39(20世纪70-80年代)、小偃6号(20世纪90年代后期)、远丰998(近期)等不同年代的4个冬小麦品种,粒重分为2种截然不同重量的大粒和小粒,播种方式设小粒单播、大粒单播以及大小粒等比例混播等3种播种方式,施肥设不施肥(CK)、施氮(N)、施磷(P)和同时施氮磷(NP)等4种方式,共48个处理。以土垫旱耕人为土为供试土样,进行盆栽试验,研究不同品种、种子大小和施肥对冬小麦生物学特性的影响。结果表明,不同品种间、大小粒播种间、不同施肥间植株株高均存在极显著差异(p〈0.01),且这些因子间存在显著的交互作用(p〈0.05)。品种间,苗期和越冬前以近期品种远丰998植株最高,灌浆期以早期品种白芒麦植株最高。株高稳定后以早期品种高,反映了育种的演变趋势。大小粒播种间,苗期和越冬前大粒株高均显著高于小粒株高,但灌浆期大小粒播种间株高差异基本消失,说明大粒种子植株在苗期生长具有一定优势。不同施肥处理间株高差异在苗期与越冬前表现一致,单施P和NP配施植株较高;灌浆期以NP配施植株株高明显高于其它施肥处理。不同品种、大小粒播种方式和施肥显著影响冬小麦分蘖和单株叶面积。白芒麦、咸农39和小偃6号的分蘖数基本一致,变化在4.37个/株-4.74个/株之间,远丰998最少,仅为2.95个/株;NP配施和施P能够显著增加分蘖数,其分蘖数几乎是不施肥(CK)和单施N的2倍;各品种大粒种子植株分蘖数均多于小粒种子植株。远丰998绿叶面积最大(45.72cm^2/单茎),白芒麦最低(仅为26.97cm^2/单茎);NP配施单株绿叶面积明显大于其它施肥处理。除远丰998大粒种子植株绿叶面积(50.42cm^2/单茎)显著大于小粒种子(41.01cm^2/单茎)外,其余品种大、小粒种子植株绿叶面积相当。就施肥处理而言,施肥对近期品种小粒种子株高、分蘖数和叶面积的促进作用相对较大,而对远期品种小粒种子植株的影响相对较小。  相似文献   

16.
An epigeic (surface dweller) earthworm species Eisenia fetida and an anecic (deep burrower) earthworm species Lampito mauritii have been tested for decomposition of kitchen waste plus cow dung. Chemical analyses of worm-worked substrates by both species showed g/kg increases in nitrogen, phosphorus and potassium and decreases in C/N and C/P ratios after 150 days of vermicomposting. However, organic carbon matter showed reduction in their amounts for 3-4 months and afterwards slightly increased up to 150 days. E. fetida produced 0.27%, 156%, 41% and 38% increases in organic carbon, nitrogen, phosphorus, and potassium as well as 61% and 29% decreases in C/N and C/P ratios as compared to control after 150 days of earthworm inoculation. In contrast, L. mauritii produced 14%, 102%, 33% and 42% increases in organic carbon, nitrogen, phosphorus and potassium as well as 43% and 14% decreases in C/N and C/P ratios as compared to control after 150 days of earthworm activity. There was moderate mineralization and faster decomposition by E. fetida in comparison to moderate mineralization and moderate decomposition by L. mauritii. The average numbers of cocoons and adults produced were greater by E. fetida than by L. mauritii after 150 days. These results indicate E. fetida may be a better adapted species for decomposition of kitchen waste plus cow dung under tropical conditions.  相似文献   

17.
过去几十年来暖春等异常气候事件发生的频次和强度显著增加, 使植物春季物候期发生了明显变化。但异常气候事件对植物春季物候积温需求的影响仍不清楚, 限制了对未来物候变化预测精度的提升。该研究利用西安植物园1963-2018年39种木本植物的展叶始期和相应气象数据, 首先根据3-4月平均气温划分了偏冷年、正常年和偏暖年, 对比了冷暖年相对于正常年的展叶始期变化。其次, 利用3种积温算法计算了各植物逐年的展叶始期积温需求, 比较了积温需求在冷暖年和正常年的差异。最后, 评估了传统积温模型在模拟偏冷或偏暖年展叶始期时的误差。结果表明, 所有植物的展叶始期在偏暖年比正常年平均早8.6天, 而在偏冷年平均晚8.2天。在偏暖年, 大多数物种展叶始期的积温需求(以5 ℃为阈值, 平均257.5度日)显著高于正常年(平均195.1度日); 在偏冷年的积温需求(平均168.0度日)低于正常年, 但在统计上差异不显著。就不同类群而言, 古老类群相对于年轻类群在偏冷年的推迟天数更多, 积温需求变化较小, 但在偏暖年无显著差异。不同生活型间物候与积温需求变化也无显著差异。造成偏暖年积温需求增加的可能原因是偏暖年冬季气温较高, 导致植物受到的冷激程度减轻, 从而抑制了后续的展叶。在正常年, 积温模型模拟木本植物展叶始期的平均误差仅为0.4-1.9天。在偏暖年和偏冷年, 模拟值分别比观测值平均早4.1天和晚3.0天。因此在预测未来物候变化时, 需要考虑气候波动条件下的积温需求变化。  相似文献   

18.
Summary The effects of vesicular-arbuscular mycorrhiza (VAM) on the growth and phosphorus uptake of cocoa seedlings (Theobroma cacao L.) grown for 100 days in polythene bags, were studied at five levels of phosphorus fertilization in both steamed and unsterile Bungor Series soil (a fine clayey, kaolinitic isohyperthermic Typic Paleudult). The cocoa seedlings responded well to phosphorus fertilization and mycorrhizal treatments. Plants inoculated with VAM fungi (Gigaspora spp.) gave the most vigorous growth and higher phosphorus in the leaf tissues in unsterile soil compared to plants grown in steamed soil. However, the mycorrhizal effect was significantly more pronounced (P<0.01) in plants grown in steamed than in unsterile soil. High levels of phosphorus application depressed mycorrhizal development. Phosphorus fertilizer applied at the rates of 250 and 500 ug g−1 soil gave maximum root colonization and spore counts in both soil types used.  相似文献   

19.
不同施肥处理对木棉叶片光合特性和幼苗生长的影响   总被引:1,自引:0,他引:1  
采用L25(53)正交实验设计设置不同氮、磷和钾肥施用量及配比﹝单株施用量分别为CO(NH2)22.0、4.0、6.0、8.0和10.0 g,Ca(H2PO4)24.0、6.0、8.0、10.0和12.0 g,KCl 0.6、1.2、1.8、2.4和3.0 g﹞,并设置不同复合肥施用量(单株施用量分别为10、20、30、40和50 g),比较了施肥后第1至第3个月木棉( Bombax ceiba Linn.)幼苗叶片光合指标﹝包括净光合速率( Pn)、水分利用效率( WUE)、PSⅡ最大光化学效率( Fv/Fm )和叶绿素相对含量( SPAD)﹞和幼苗生长指标(包括株高增长量、地径增长量和叶面积增长量)的变化。结果表明:总体来看,不同施肥处理组木棉幼苗叶片的Pn和WUE值升高,幼苗的株高增长量、地径增长量和叶面积增长量增加,但不同施肥处理对叶片Fv/Fm和SPAD值的影响较小;复合肥对叶片光合生理特性和幼苗生长的影响也较小。在施肥后的第1至第3个月,单株施用量氮肥4.0或6.0 g,磷肥4.0或8.0 g,钾肥1.2、1.8或3.0 g处理组幼苗叶片的Pn和WUE值显著高于对照(不施肥)和大多数处理组;单株施用量氮肥4.0或6.0 g、磷肥4.0~12.0 g、钾肥1.2~3.0 g处理组幼苗的株高增长量、地径增长量和叶面积增长量也均较高。综合分析结果显示:氮肥对木棉幼苗光合生理特性及生长的影响最大,钾肥次之,磷肥最小。综合考虑Pn值、WUE值、株高增长量、地径增长量和叶面积增长量,木棉苗期的适宜单株施肥量为N 1.84或2.76 g、P2 O50.72~2.16 g和K2 O 0.72~1.80 g。  相似文献   

20.
Beech seedlings were infected with the root rot pathogen Phytophthora citricola to study its impact on leaf physiology and water status. Net photosynthesis rate decreased two days after inoculation in infected seedlings. In contrast, electron quantum yield of photosystem II, leaf water potential, and total water consumption were only slightly impaired until 6 dpi. At the same time, wilt symptoms occurred on leaves. These results indicate the involvement of a mobile signal triggering the early changes in leaf physiology by root infection. As the elicitin gene of P. citricola was induced during root infection, we purified and characterised the elicitin protein and tested its ability to change leaf physiological parameters of beech and tobacco plants. P. citricola produced a single acidic elicitin (citricolin), which caused necrosis and decreased gas exchange of tobacco leaves. Furthermore, it induced an oxidative burst in tobacco cell suspension culture. However, none of these effects were observed in beech.  相似文献   

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