转Bt基因棉田节肢动物群落结构特征研究

比较研究了转Bt基因棉--保铃棉、中棉30和常规棉常规防治、常规棉不防治4种类型棉田的节肢动物群落构成及结构.结果表明,保铃棉、中棉30的物种丰富度有一定降低(2.4%～16.3%),个体总量显著减小(71.0%～78.3%).其中植食性亚群落的优势种组成及次序改变,其个体总量降低最多,捕食性和寄生性亚群落的个体总量明显增加.中棉30、保铃棉与常规棉不防治处理群落的相似系数依次最高(0.8243)、次高(0.7320),保铃棉与常规棉常规防治居第三(0.3380),常规棉常规防治与常规棉不防治居第四(0.3128),中棉30与常规棉常规防治最小(0.2665).各处理多样性指数和均匀度值的高低次序为中棉30(分别为2.3712和0.6428)＞常规棉不防治(2.3654和0.6251)＞保铃棉(2.1364和0.5791)＞常规棉常规防治(1.0877和0.2949),优势度次序为常规棉常规防治(0.8726)＞保铃棉(0.3528)＞常规棉不防治(0.1178)＞中棉30(0.1048).转Bt基因棉的害虫防治宜采取与常规棉不同的IPM策略和方法.     

转基因玉米对田间节肢动物群落多样性的影响

通过对转基因耐除草剂(EPSPS)抗虫(Cry1Ab)玉米转化体‘DBN9936’、受体玉米‘DBN318’、常规玉米‘先玉335’和喷施除草剂的转化体‘DBN9936’玉米田中节肢动物种类及数量的调查, 评价转基因玉米对田间节肢动物群落多样性的影响。2015年和2017年我们采用直接观察法、陷阱调查法和剖秆法对田间节肢动物进行调查, 采用聚类分析、物种累积曲线等方法对数据进行分析, 并比较了4个处理玉米田节肢动物群落的Margalef丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数、优势集中性指数和群落相似性指数的差异及其随时间变化的规律。调查期间共记录节肢动物20目80科; 转化体玉米‘DBN9936’ (2015: 10.3 ± 2.6头, 2017: 3.3 ± 1.7头)和喷施除草剂的转化体玉米‘DBN9936’ (2015: 6.0 ± 1.5头, 2017: 17.0 ± 0.6头)上鳞翅目昆虫的数量明显低于受体‘DBN318’ (2015: 20.0 ± 3.2头, 2017: 24.0 ± 6.0头)和‘先玉335’ (2015: 21.0 ± 8.9头, 2017: 26.7 ± 2.0头); 物种累积曲线呈典型的抛物线, 各类玉米田间总体物种丰富度差异较小; 玉米生育期节肢动物调查结果累计数量的功能团组成及其丰富度、多样性、均匀度、优势集中性间均无明显的差异, 各类指数随时间变化的动态趋于一致, 群落间相似性程度较高。转基因玉米‘DBN9936’对鳞翅目害虫有明显的抗性, 对非靶标节肢动物无显著的影响, 对田间节肢动物的群落多样性、均匀度、丰富度、优势集中性等没有明显的影响。     

转RRM2基因棉生长势和产量及对棉田节肢动物群落的影响

为了评估新型转基因棉花的育种价值, 评价其对棉田生态环境安全性的影响, 2012-2013年连续2年以新型转RRM2基因棉花(Gossypium hirsutum)为材料, 以其亲本‘中棉所12’为对照, 系统研究了棉田节肢动物群落的结构与组成、群落特征参数及其季节性动态变化, 同时结合气候条件分析比较了转基因棉花和非转基因棉花的生长势和产量构成因素。结果表明: 相同年份新型转RRM2基因棉田昆虫群落、害虫亚群落和天敌亚群落的结构与组成、多样性指数、均匀度指数、优势集中性指数及棉花生长期相对丰度动态变化均与对照无显著差异; 与2012年相比, 2013年转基因棉田和非转基因棉田节肢动物群落、棉花生长及产量构成因素的各项指标总体上呈下降趋势; 转基因棉田和非转基因棉田优势天敌功能团动态均滞后于优势害虫功能团, 因此棉花生长前期应适时防治棉花害虫。     

麦套夏播转Bt基因棉R93-6对昆虫群落的影响

以转Bt(Bacillusthuringiensis)基因棉品系R93-6为试验材料,以中棉所16号为对照,研究了在麦套夏播条件下转基因棉对昆虫群落的影响。结果表明,转基因棉田昆虫群落、害虫和天敌亚群落的多样性指数和均匀度指数均低于常规棉田,而优势集中性则高于常规棉田,所以转基因棉田昆虫群落、害虫和天敌亚群落的稳定性不如常规棉田,某种害虫大发生的可能性较大。对季节性变化格局的研究表明,转基因棉田昆虫群落可以划分为前期(6月初至7月下旬)、中期(7月底至8月底)和后期(9月份以后)三个发展阶段,根据不同阶段害虫和天敌发生的特点, 提出了害虫综合治理的策略。即前期害虫的防治应以生物生态调控为主;中期以化学防治为主,以生物生态调控为辅,协调好生物防治和化学防治的矛盾;后期应以生物生态调控为主,并加强农业防治。     

转Bt基因棉田昆虫群落多样性及其影响因素研究

运用群落生态学的方法,研究了转Ｂｔ（Ｂａｃｉｌｌｕｓ ｔｈｕｒｉｎｇｉｅｎｓｉｓ）基因棉田昆虫群落及害虫和天敌亚群落多样性,对多样性及其主要组成成分－物种数、个体数、均匀度、优势集中性进行了通径分析。试验设３个处理：转基因棉自然控制（全生育期不施用任何农药,简称自控田）、转基因棉综合防治（采取综合防治措施,简称综防田）和常规棉自然控制（常规品种,全生育期不施用任何农药,简称对照田）。结果表明：转基     

盐碱旱地转基因抗虫棉田昆虫群落多样性

棉花是耐干旱和耐盐碱的经济作物。随着土壤的盐碱化和干旱化, 在人口数量和植棉成本剧增的背景下, 我国黄河流域和长江流域棉花种植面积锐减, 棉花种植被迫向滨海盐碱地和内陆及西北干旱地区转移。本文于2013年和2014年在山东东营滨海盐碱地和河北枣强半干旱轻度盐碱地以非转基因棉(‘中棉所49’)为对照, 以转Bt基因棉(‘中棉所79’)为试验材料, 分别作施农药和不施农药处理, 于每年5月初到9月中旬, 调查取样点棉株及地面上害虫及其天敌的种类和数量, 并分析不同施药处理下转基因和非转基因棉田昆虫群落的生物多样性参数差异。结果表明, 施药和不施药转Bt基因棉田昆虫群落和害虫亚群落昆虫的个体总数均低于非转基因棉田, 其中昆虫群落和害虫亚群落个体数在二者之间差异显著; 转Bt基因棉田昆虫群落和害虫亚群落昆虫的多样性指数和均匀度指数均高于非转基因棉田, 而优势集中性指数均低于非转基因棉田, 但差异均不显著。施药条件下两种棉田的昆虫群落和害虫亚群落昆虫个体总数、多样性指数和均匀度指数均低于不施药棉田, 优势集中性指数均高于不施药棉田, 但转基因棉田和非转基因棉田之间无显著差异。表明转基因抗虫棉在盐碱旱地对棉田靶标害虫具有较好的控制作用, 棉田昆虫群落稳定性较高, 昆虫群落对外界的入侵和干扰缓冲能力强, 而化学农药的使用对昆虫群落杀伤力较大, 容易导致某种昆虫的抗性产生和昆虫群落的不稳定, 但比非盐碱旱地棉田昆虫群落生物多样性低, 棉田生态系统更简单。     

转RRM2基因棉田昆虫群落多样性及其时序动态

为了评价新型转基因棉花在长江生态区对棉田生态环境安全性的影响, 2013-2015年作者以新型转RRM2基因棉花(Gossypium hirsutum)为材料, 以其亲本‘中棉所12’为对照, 在安徽省沿江棉区系统研究了转基因棉田昆虫群落、害虫亚群落和天敌亚群落的结构与组成、个体数量、群落特征参数及其季节性动态变化。结果表明: 转RRM2基因棉田的主要类群组成、优势类群与非转基因棉田没有差异, 但在2013年转RRM2基因棉田棉蚜个体数量显著高于非转基因棉田, 叶螨类、棉铃虫和其他鳞翅目的个体数量显著低于非转基因棉田, 在其他年份没有显著差异; 其他类群的个体数量在两类棉田间没有显著差异。在棉田害虫发生量大的年份, 转RRM2基因棉田的昆虫群落个体数量较非转基因棉田增加, 物种丰富度较非转基因棉田减少, 但差异不显著, 而两类棉田年度间均差异显著。转RRM2基因棉田昆虫群落和害虫亚群落的全生育期多样性指数、均匀度指数和优势集中性指数与非转基因棉田没有显著差异; 其天敌亚群落的三个指数在2013年与非转基因棉田差异显著, 其他年份没有显著差异; 两类棉田年度间差异均不显著。转RRM2基因棉田昆虫群落、害虫亚群落和天敌亚群落个体数量、群落特征参数的时序动态与非转基因棉田较一致, 具季节性波动; 在群落个体数量高峰期, 群落多样性指数和均匀度指数处于低谷, 而优势集中性指数则相反; 昆虫群落、害虫亚群落的季节波动明显, 天敌亚群落的季节性变化较平缓。因此, 转RRM2基因棉花对棉田昆虫群落的结构与组成、群落特征参数及其时序动态没有显著影响, 但在气候适宜年份, 转RRM2基因棉田的害虫发生量可能增大。     

转双抗虫基因107杨节肢动物群落特征及相对稳定性

于2015年5—9月对唐山市滦南县苗圃场内的转双抗虫基因(Bt Cry1Ac和API基因)107杨(简称:转抗虫基因107杨)及未转基因107杨(简称:对照杨)进行了节肢动物群落调查,利用群落特征指数、群落相似性系数、群落相对稳定性和主成分分析法对转抗虫基因107杨节肢动物群落特征、相似性、相对稳定性及主成分进行对比分析。调查共获得节肢动物6818头,隶属于2纲,8目,43科,58种。研究结果表明:转抗虫基因107杨和对照杨节肢动物群落中以鳞翅目、鞘翅目、膜翅目、双翅目昆虫为主要类群,其中鳞翅目昆虫个体数量最多;鳞翅目和半翅目昆虫个体数量与对照杨差异显著;在功能类群上,转抗虫基因107杨食叶昆虫个体数量较对照杨显著减少,刺吸昆虫个体数量显著增加;转抗虫基因107杨节肢动物群落多样性指数、均匀度指数较高,优势度指数较低,节肢动物群落物种分布较均匀;相似性结果显示,物种组成与对照杨相似度较高;转抗虫基因107杨节肢动物群落物种间在数量上的制约作用较强;主成分分析表明食叶昆虫物种数量与个体数量、刺吸昆虫物种数量和其他植食性昆虫个体数量是影响转抗虫基因107杨与对照杨节肢动物群落变化的共同主导因子。     

2009-2013年Bt棉田节肢动物群落多样性动态变化

研究多年种植转Bt基因棉花对棉田节肢动物群落昆虫结构与组成、生物多样性的影响,明确其变化趋势,可为棉田害虫综合治理与生态调控、转Bt基因棉花环境安全性评价提供科学借鉴。于2009-2013年连续5年对转Bt基因棉花中棉所41和非转基因棉花中棉所49棉田节肢动物群落进行了系统调查,并结合5a气象因子的变化,分析了5年内棉田节肢动物群落相关参数的变化趋势。结果分析表明,2009-2013年中棉所41棉田昆虫群落、害虫亚群落和天敌亚群落所属目数有所上升,但差异不显著;所属科数、物种数、个体总数均呈现先上升后下降的趋势,个别年份差异显著,其余年份基本保持不显著的波动水平;昆虫群落和害虫亚群落多样性指数呈下降的趋势,至2013年下降达到显著水平,其余年份之间差异不显著,天敌亚群落多样性指数无显著变化;昆虫群落、害虫亚群落和天敌亚群落均匀性指数无显著变化;昆虫群落和害虫亚群落优势集中性指数有所上升,至2013年差异达到显著水平,天敌亚群落优势集中性各年份间无显著变化;与中棉所49棉田相比,相同年份中棉所41棉田昆虫群落、害虫亚群落和天敌亚群落结构与组成、多样性指数、均匀性指数和优势集中性指数均无显著差异。可见,短期内非剧烈天气变化对转基因棉田节肢动物群落、害虫亚群落和天敌亚群落在结构与组成、生物多样性方面没有明显的影响。     

蚜虱净对苜蓿田节肢动物群落结构及动态的影响

以物种丰富度(S)、个体数量(N)、香农指数(Shannon’sindex,H′)和均匀度指数(E)作为多样性指标,研究了蚜虱净对苜蓿田节肢动物群落结构和季节动态的影响.结果表明:蚜虱净对天敌亚群落物种数的影响大于害虫亚群落,使总群落和害虫亚群落的优势集中性显著增加,但5月底施药对传粉蜜蜂类亚群落的优势集中性无显著影响.喷药初期,蚜虱净显著降低了蚜虫、蓟马等害虫数量,7d后蚜虫、蓟马等种群数量迅速回升,40d后超过对照;施药初期天敌亚群落的物种数大幅减少,多样性和均匀度指数较低,7d后天敌的物种数逐渐回升,到后期与对照田基本一致,但个体数量一直未恢复至对照水平.     

Neighbouring crop diversity mediates the effect of Bt cotton on insect community and leaf damage in fields

Effects of large-scale cultivation of transgenic crops on agricultural biodiversity remain unclear, particularly in the context of complex ecological interactions between transgenic crops and other organisms. Here we conducted a comprehensive survey to investigate the number of species, population abundance, community evenness and dominance of insects and weeds as well as leaf damage to weeds in Bt and non-Bt cotton fields at 27 sites across northern China. The role of neighbouring crop diversity around cotton fields in controlling insects and weeds in the cotton fields was also assessed. In addition, we conducted a 3-year field experiment to verify the results of the survey. Weed diversity in Bt and non-Bt cotton fields was similar, but the species number and diversity indices of insects are significantly decreased in Bt fields aligning with reduced leaf damage to broadleaf plant species including cotton as well as crops in neighbouring plots. The leaf damage to Bt and non-Bt cotton negatively associates with the diversity of neighbouring crops in cotton fields. Our study demonstrates the neighbouring crop diversity mediates the effects of Bt crops on agricultural diversity in complex interactions among transgenic crops, in-field weed and insect communities, and neighbouring crops.

     

Fitness of Bt‐resistant cabbage loopers on Bt cotton plants

Development of resistance to the insecticidal toxins from Bacillus thuringiensis (Bt) in insects is the major threat to the continued success of transgenic Bt crops in agriculture. The fitness of Bt‐resistant insects on Bt and non‐Bt plants is a key parameter that determines the development of Bt resistance in insect populations. In this study, a comprehensive analysis of the fitness of Bt‐resistant Trichoplusia ni strains on Bt cotton leaves was conducted. The Bt‐resistant T. ni strains carried two genetically independent mechanisms of resistance to Bt toxins Cry1Ac and Cry2Ab. The effects of the two resistance mechanisms, individually and in combination, on the fitness of the T. ni strains on conventional non‐Bt cotton and on transgenic Bt cotton leaves expressing a single‐toxin Cry1Ac (Bollgard I) or two Bt toxins Cry1Ac and Cry2Ab (Bollgard II) were examined. The presence of Bt toxins in plants reduced the fitness of resistant insects, indicated by decreased net reproductive rate (R₀) and intrinsic rate of increase (r). The reduction in fitness in resistant T. ni on Bollgard II leaves was greater than that on Bollgard I leaves. A 12.4‐day asynchrony of adult emergence between the susceptible T. ni grown on non‐Bt cotton leaves and the dual‐toxin‐resistant T. ni on Bollgard II leaves was observed. Therefore, multitoxin Bt plants not only reduce the probability for T. ni to develop resistance but also strongly reduce the fitness of resistant insects feeding on the plants.     

转基因杨树林下种植转基因棉花对转基因杨棉复合系统内节肢动物群落多样性的影响

【目的】转Bt基因棉花和转Bt基因杨树在我国已推广使用。本研究的目的是调查和分析不同转基因杨棉复合系统内地上节肢动物群落多样性变化,为转基因杨树大规模应用提供生态安全方面的数据。【方法】2019年4-10月,在河北任丘采取欧洲黑杨Populus nigra林下种植转基因棉花Gossypium hirsutum的模式,设置转基因杨树 转基因棉花(复合生态系统1)和非转基因杨树-转基因棉花(复合生态系统2)两种杨棉复合系统,调查杨树和棉花地上部植株节肢动物种类和个体数量,比较节肢动物各功能群的物种数量和个体数量以及香农指数、优势集中性指数、均匀度指数等群落多样性指数,并测定了转基因杨树和棉花叶片Bt蛋白含量。【结果】复合生态系统1中转基因杨树和棉花各自植株上鳞翅目种群累计个体数均显著低于复合生态系统2相应植株上的个体数量。转基因杨树上叶甲类累计个体数量显著高于非转基因杨树上的,寄生蜂类累计个体数量则显著低于非转基因杨树上的。在6月5日、6月21日和9月7日的调查中,转基因杨树上的节肢动物群落香农指数显著高于非转基因杨树上的。除鳞翅目害虫外,2个复合系统中棉株上节肢动物各功能群累计个体数量无显著性差异,香农指数、优势集中性指数和均匀度指数随时间变化的趋势基本一致且同一调查时间无显著性差异,仅在8月17调查中复合生态系统1中棉株上节肢动物香农指数显著高于复合生态系统2棉株上的。将杨树和棉花上节肢动物各类群累计数量相加作为系统整体,复合生态系统1和复合生态系统2在香农指数、优势集中性指数和均匀度指数数值上无显著差异。在调查后期,2个复合系统中节肢动物种群均向杨树叶片聚集。转基因棉花叶片Bt蛋白含量在各调查期均显著高于转基因杨树叶片的。【结论】转基因杨树对靶标害虫种群数量有较好的控制作用,对同系统内棉花上鳞翅目害虫数量亦有协同控制作用。转基因杨棉复合系统中地上节肢动物群落结构稳定,对系统内棉花地上部节肢动物群落多样性无显著影响。靶标害虫对转Bt基因杨树的抗性发展需持续监测。     

Field and laboratory evaluations of transgenic cottons expressing one or two Bacillus thuringiensis var. kurstaki Berliner proteins for management of noctuid (Lepidoptera) pests

Field studies were conducted from 1999 to 2001 to evaluate the efficacy of the transgenic cotton, Gossypium hirsutum (L.), genotype, Bollgard II (Monsanto 15985), which expresses two Bacillus thuringiensis Berliner (Bt) proteins (Cry1Ac + Cry2Ab) that are active against lepidopterous pests. Bollgard II was compared with Bollgard (DP50B), which expresses only one Bt protein (Cry1Ac), and, in all tests, the conventional variety, DP50, was used as a non-Bt control. Larval populations of the bollworm, Helicoverpa zea (Boddie), and the soybean looper, Pseudoplusia includens (Walker), were significantly lower in Bollgard II than in Bollgard and conventional cotton, and the proportion of fruit damaged by H. zea was also lower. Fall armyworm, Spodoptera frugiperda (J. E. Smith), populations were lower in Bollgard II than in Bollgard, although not significantly. Field tests were supplemented with laboratory bioassays in 2001 to compare mortality of S. frugiperda, and beet armyworms, Spodoptera exigua (Hübner), feeding on these genotypes. Mortality of both species was significantly greater on Bollgard II plant material than on either Bollgard or conventional cotton. This study demonstrated that the dual-toxin Bollgard II genotype is highly effective against lepidopterous pests that are not adequately controlled by the current single-toxin Bollgard varieties. If toxin expression in future Bollgard II varieties remains consistent with that of Monsanto 15985, supplemental insecticides will be reduced, and may be eliminated for lepidopterous pests in South Carolina.     

Field efficacy and seasonal expression profiles for terminal leaves of single and double Bacillus thuringiensis toxin cotton genotypes.

Examination of commercial Cry1Ac transgenic Bacillus thuringiensis Berliner (Bt) cotton varieties (Bollgard, Monsanto, St. Louis, MO) and an experimental Cry1Ac + Cry2Ab transgenic Bt cotton variety (Bollgard II, Monsanto) for lepidopteran field efficacy was conducted during the 2000 growing season. In addition, a commercially available (Envirologix, Portland, ME) quantification assay (ELISA) was used to measure and profile the expression levels of Cry proteins in two of these varieties ['DP50B, Bollgard'; 'DP50BII, Bollgard II' (Delta & Pine Land, Scott, MS)]. Populations of beet army worms, Spodoptera exigua (Hübner), and soybean loopers, Pseudoplusia includens (Walker), were significantly lower (P < 0.05) in Bollgard II plots compared with Bollgard. Population numbers for fall army worms, Spodoptera frugiperda (J. E. Smith), and salt marsh caterpillars, Estigmene acrea (Drury), were lower in Bollgard II plots compared with Bollgard but means did not differ significantly (P > 0.05). Single and dual-toxin genotypes remained superior (P < 0.05) compared with conventional cotton against the tobacco budworm, Heliothis virescens (F.). The addition of Cry2Ab had no significant (P > 0.05) impact on Cry1Ac expression in Bollgard II compared with Cry1Ac expression in Bollgard. Furthermore, throughout the season Cry2Ab was present at much higher levels in the plant compared with Cry1Ac for Bollgard II plants. Possible species-specific reasons for increased efficacy of Bollgard II over Bollgard are discussed.     

南京江心洲鸟类群落特征

2004～2006年,分冬夏两季对南京江心洲4种典型生境(居民区、农田区、林区及湿地区)的鸟类资源进行了调查。共记录鸟类67种,隶属10目25科。对冬夏两季不同生境中鸟类群落的密度、现存生物量、多样性指数、均匀度、优势度的对比研究表明,冬季鸟类密度、物种多样性和均匀度均高于夏季,而优势度、现存生物量则夏季高于冬季。在不同生境中,林区鸟类密度、多样性指数最高;居民区优势度最高;均匀度指数冬季林区最高,夏季居民区最高。     

Comparative production of Helicoverpa zea (Lepidoptera: Noctuidae) from transgenic cotton expressing either one or two Bacillus thuringiensis proteins with and without insecticide oversprays

Transgenic cotton, Gossypium hirsutum (L.), expressing either one or two Bacillus thuringiensis ssp. kurstaki Berliner (Bt) proteins was compared with the conventional sister line in field experiments with regard to production of bollworm, Helicoverpa zea (Boddie), and bolls damaged by bollworm. The relative numbers of bollworms that developed on Bollgard (Monsanto Co., St. Louis, MO), Bollgard II (Monsanto Co.), and conventional cotton were estimated under nontreated conditions in 2000 and both insecticide-treated and nontreated conditions in 2001-2002 in North Carolina tests. Averaged across seven field studies under nontreated conditions, Bollgard cotton generated statistically similar numbers of large (L4-L5) bollworm larvae compared with the conventional variety; however, Bollgard cotton produced significantly fewer damaged bolls and bollworm adults than the conventional variety. Production of large larvae, damaged bolls, and adults was decreased dramatically by Bollgard II cotton as compared with Bollgard and conventional varieties. When comparing insecticide-treated and nontreated cotton genotypes, both Bt cotton sustained less boll damage than the conventional variety averaged across insecticide regimes; furthermore, Bollgard II cotton had fewer damaged bolls than the Bollgard variety. When averaged across cotton genotypes, pyrethroid oversprays reduced the numbers of damaged bolls compared with the nontreated cotton. Insecticide-treated Bollgard cotton, along with insecticide-treated and nontreated Bollgard II cotton reduced production of bollworm larvae, pupae, and adults. However, the addition of pyrethroid oversprays to Bollgard II cotton seemed to be the best resistance management strategy available for bollworm because no bollworms were capable of completing development under these conditions.     

转Bt基因水稻“赣绿1号”对田间节肢动物群落的影响

【目的】研究转Bt基因水稻"赣绿1号"对田间节肢动物群落的影响。【方法】以含有转cry1Ab/Ac基因水稻与常规对照为材料,2012和2013连续两年在江西南昌县开展田间试验。【结果】转Bt基因水稻"赣绿1号"田间节肢动物群落结构物种数、优势集中度、香农指数和均匀性指数与对照相比,均无显著差异;"赣绿1号"田间节肢动物5类功能团的优势度与对照田均无显著差异;"赣绿1号"田与对照田田间节肢动物群落相异性数值大多较低。【结论】转Bt基因水稻"赣绿1号"对田间节肢动物群落结构没有明显的不利影响。