锐星防治水稻二化螟田间药效试验

小区试验表明，锐星可湿性粉剂对水稻二化螟具有较好的保苗杀虫效果，每667m^2使用70g的防效分别是82．74％、77．89％，优于90％杀虫单原粉50g，作为无公害生物杀虫剂其应用前景颇为广阔。     

Transgenic Bt corn varietal resistance against the Mexican rice borer,Eoreuma loftini (Dyar) (Lepidoptera: Crambidae) and implications to sugarcane

The Mexican rice borer, Eoreuma loftini (Dyar), attacks crops including corn, Zea mays L., rice, Oryza sativa L., sorghum, Sorghum bicolor (L.) Moench, and sugarcane, Saccharum spp. Strongly resistant varieties of any kind, native or otherwise, have not been identified. A field plot corn variety test using two transgenic Bt varieties, Pioneer 31G71, expressing the Cry1F insecticidal protein, and Golden Acres 28V81, expressing the Cry1A.105, Cry2Ab2, and Cry3Bb1 insecticidal proteins, and two non-Bt controls, Dekalb DKC 69-72 and BH Genetics 9050, all four commonly grown in the Lower Rio Grande Valley of Texas, showed that, although oviposition preference was not affected, 28V81 resisted larval stalk boring to the extent that Mexican rice borer injury was almost non-existent. Pioneer 31G71 was infested nearly as much as the controls, but larval development to adulthood was reduced by ≈70%. Rearing larvae on 5, 50, 500, and 5000 μg of corn leaf tissue per ml of artificial diet showed that, while the three lowest concentrations did not affect larval growth and development, the high concentration of 28V81 reduced survivorship to the pupal stage, decreased weight of 4-wk-old larvae, and prolonged development to pupation. Lower numbers of pheromone trap-captured adults at the edges of commercial Bt and non-Bt corn fields showed that populations were lower at the Bt cornfields, suggesting a lesser rate of adult production. Because corn is a preferred host plant over sugarcane, sorghum or rice, use of resistant transgenic Bt corn varieties will likely protect the crop from the substantial injury that can be caused by the pest. This study also suggests that Bt genes might result in similarly strong resistance when inserted in other vulnerable crops such as sugarcane.     

Introduction of Bacillus thuringiensis(Bt) gene does not reduce potassium use efficiency of Bt transgenic cotton(Gossypium hirsutum L.)

Background: Potassium(K) deficiency has become a common field production problem following the widespread adoption of Bacillus thuringiensis(Bt) transgenic cotton(Gossypium hirsutum L.) worldwide. The purpose of this study was to clarify whether the introduction of Bt gene directly reduces the K-use e ciency of cotton to induce K deficiency.Results: The cotton variety, Jihe 321(wild type, WT) and its two Bt(Cry1Ac)-transgenic overexpression lines(OE-29317, OE-29312) were studied in field with lo...     

二化螟对氟虫腈抗性初探

 采用点滴测定法，于2001~2004年对江、浙、皖3省12个县市的二化螟进行了氟虫腈的抗性调查。江苏及安徽等地二化螟对氟虫腈仍处于敏感状态，但江苏无锡和浙江慈溪二化螟的敏感性明显下降（抗性倍数RR分别为3.1和3.6倍），浙江苍南二化螟已出现中等水平的抗性（RR为21.2倍）。由此认为，二化螟目前仍处于对氟虫腈抗性发展的早期阶段。解毒酶抑制剂的活体增效实验发现，TPP、DEM能明显提高氟虫腈对抗性二化螟的毒力（增效比SR分别为1.8和1.6），但PBO在敏感性和抗性二化螟中的增效作用均不显著（SR为1.1~1.2）。表明酯酶和谷胱甘肽转移酶与二化螟对氟虫腈抗性的形成有一定关系。不同杀虫剂的比较毒力测定表明，三唑磷和敌百虫由于产生了抗性，对二化螟的毒力很低，乙酰甲胺磷本身对二化螟的毒力也不高，已很难再用来防治抗性二化螟。但哒嗪硫磷、二嗪磷、溴氰菊酯和阿维菌素对二化螟的毒力较高，而且尚没有明显的抗性产生，在二化螟抗性治理中，可以用作氟虫腈的轮换防治药剂。     

Selecting strategies for rice stem borer management using the Analytic Hierarchy Process (AHP)

Selecting appropriate strategies for pest control has become an issue of major concern, but research on decision making regarding this issue is limited. An analytic hierarchy process (AHP) approach for selecting strategies for the management of rice stem borer [Chilo suppressalis (Walker)] in paddy fields of Sari county of Mazandaran province in Iran was developed. Agricultural faculty members, experts of a local plant protection unit, local extension agents, and elite farmers in the study area participated in the project to determine the suitability of four common pest control methods (i.e., chemical control, cultural control, biological control, pheromone trapping) for rice stem borer management, based on 10 main criteria and 32 sub-criteria identified through pertinent literature and focus group discussions. All the examined alternatives of pest control were preferred to some extent for rice stem borer management. Control effectiveness, relative advantages, social usefulness, and technical support were the most important criteria for assessing strategies for rice stem borer management, followed by observability, ease of use, trialability, farmer's self-efficacy, compatibility, and farm characteristics. Overall, chemical control ranked first, being superior to the other three methods with respect to six main criteria of the model (relative advantages, trialability, observability, farmer's self-efficacy, farm characteristics, and control effectiveness). Biological control ranked second at the overall level, being superior to cultural control and pheromone trapping in the three remaining main criteria (i.e., technical support, compatibility, and social usefulness). Pheromone trapping ranked first only with respect to ease of use criteria. The proposed model constitutes a flexible tool for decision making in pest control with high applicability among policy makers in the government and local agricultural office and extension agents; it could greatly assist extension programs to effectively select strategies for rice stem borer management or similar pest problems in various agricultural sites.     

Mechanism of rice variety resistance to the yellow stem borer, Scirpophaga incertulas (Walker)

Yellow stem borer (YSB), Scirpophaga incertulas (Walker) has become the main rice insect pest once again along the Changjiang River sinee 1990s. Unfortunately, no rice variety with resistance to YSB has been reported so far.     

Mechanism of rice variety resistance to the yellow stem borer, Scirpophaga incertulas (Walker)

Yellow stem borer (YSB), Scirpophaga incertulas (Walker) has become the main rice insect pest once again along the Changjiang River sinee 1990s. Unfortunately, no rice variety with resistance to YSB has been reported so far.     

gus reporter gene assisted selection for striped stem borer resistant transgenic rice carrying a cry1Ab gene from Bt

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二化螟对杀虫单抗性现实遗传力与遗传方式

 以2001年田间采集的温州二化螟为起始种群，在室内饲养24代期间，用点滴法处理4龄幼虫进行杀虫单筛选19代，得到抗性品系WZ R；与敏感基线相比， WZ R品系对杀虫单抗性达774.5倍，比筛选前上升25.0倍；根据前期连续6代（F3~F8）筛选估计的抗性现实遗传力（h2，0.230）显著低于根据后期连续5代（F19~F23）筛选的h2（1205），而中间不连续筛选（F9~F18，10代中有4代未筛选）的h2最小（0.024）。用毒力回归线法对WZ R品系进行抗性遗传分析表明，杀虫单抗性为不完全显性（正反交显性度分别为0.56和0.63）、常染色体遗传，抗性不属于单个主基因控制。     

Comparison of stem borer damage and resistance in semidwarf Indica rice varieties and prototype lines of a new plant type

The rice (Oryza sativa L.) “new plant type” (NPT), currently under development at the International Rice Research Institute, Philippines, differs in genetic background and plant architecture from the semidwarf Indica varieties that now predominate in tropical lowland areas. The NPT is derived from tropical Japonica germplasm and has fewer and larger stems and panicles than do semidwarf Indica varieties. We compared stem borer damage and resistance in NPT lines and semidwarf Indica varieties under field and greenhouse conditions. Stem borer damage in field plots of the NPT lines IR65564 and IR68011 was higher than in plots of the Indica varieties IR64 and IR72 during the 1999 dry season but not the wet season. In both seasons, IR68011 had higher densities of egg masses of the striped stem borer (SSB, Chilo suppressalis) than did the other three entries. There were no consistent differences among entries in density of egg masses of the yellow stem borer (YSB, Scirpophaga incertulas). In the 2000 wet season, stem borer populations were low, but SSB egg masses were found only on IR68552-100, the only NPT line in the experiment. In all three seasons, NPT lines had higher proportions of SSB larvae and pupae in stems after harvest, and lower proportions of YSB, than did Indica varieties. In artificially infested field cages, SSB larval survival was highest on reproductive stage plants of IR68011 in the 1999 dry season and there was a trend of higher YSB adult weight on IR68011 in the 1999 dry and wet seasons. Three NPT lines and three Indica varieties evaluated under greenhouse conditions showed no consistent differences in resistance to either stem borer species, as measured by percent survival from egg to adult and female development time and weight. The lack of consistent differences in stem borer survival and development between the NPT lines and Indica varieties was contrary to the expectation that the morphology of the NPT would render it more susceptible to stem borers. Our results indicate that NPT lines are not consistently or strongly more susceptible to stem borers than are improved Indica varieties and suggest that ovipositional attractiveness to SSB is a factor contributing to higher stem borer damage to some NPT lines.     

Trapping effect of synthetic pheromone blends on two stem borers, Chilo suppressalis and Scripophaga incertulas

Two internal feeders of rice plant, rice stem borer, Chilo suppressalis (Walker) and yellow stem borer, Scirpophaga incertulas (Walker) are major hurdles in achieving higher yields in Central China. Synthetic sex pheromone was an effective method to control the two borers. A new series of sex pheromone blends were formulated and tested.     

水稻挥发物对二化螟幼虫趋性行为的影响

 利用Y型嗅觉仪研究了水稻挥发物对二化螟初孵幼虫和3龄幼虫的趋性影响。处理包括健康苗与空白对照、二化螟为害苗与空白对照、稻纵卷叶螟为害苗与空白对照、健康苗与二化螟为害苗、健康苗与稻纵卷叶螟为害苗、二化螟为害苗与稻纵卷叶螟为害苗。结果表明，水稻挥发物对二化螟初孵和3龄幼虫都表现出显著的引诱作用。二化螟幼虫对不同处理水稻（健康苗、二化螟为害苗和稻纵卷叶螟为害苗）挥发物之间的趋向选择无显著差异。     

Photodegradation of emamectin benzoate and its influence on efficacy against the rice stem borer, Chilo suppressalis

Emamectin benzoate, a novel insecticide with characteristics of translaminar movement into plant leaf tissue, was derived from the avermectin family with improved thermal stability, greater water solubility and a broader spectrum of insecticidal activity than avermectin. To quantify UV photodegradation of emamectin benzoate, HPLC analysis was conducted to quantify residues of MAB1a, the major component in emamectin benzoate, after exposure to UV light for different lengths of time. Results showed both MAB1a concentration and length of UV light exposure (0-120 h) had significant impacts on photodegradation rate. The degradation rate increased as exposure duration increased, but decreased as initial MAB1a concentration increased. Four UV protectants, kojic acid, sodium ligninsulfonate, soybean lecithin and milk, were evaluated for their effect on UV degradation. Results showed that kojic acid could effectively reduce the photodegradation of MAB1a. In addition, the photodegradation of emamectin benzoate was also examined for its influence on the efficacy against the rice stem borer, Chilo suppressalis. The results of the bioassays were consistent with those of HPLC analysis. The initial concentration of emamectin benzoate and exposure duration to UV light both had significant influences on the efficacy against C. suppressalis. As the UV exposure time increased, the efficacy of emamectin benzoate against C. suppressalis decreased. The results indicated that UV photodegradation has a significant effect on the efficacy of emamectin benzoate against C. suppressalis and the effect is concentration-dependant. In addition to understanding the critical factor of UV exposure length, this study also showed that maintaining emamectin benzoate concentration above a certain level in the formulation and the application solution, and applying UV protectants may reduce photodegradation and increase efficacy against target pests.     

一株对玉米螟高毒力的苏云金芽孢杆菌的鉴定及其杀虫活性

从田间土壤中收集并分离获得野生菌株,进行菌体、伴孢晶体形态学观察及分子生物学鉴定,测定其对玉米螟及水稻二化螟的室内生物活性。结果表明,该菌株革兰氏染色阳性,产生的伴孢晶体形状多为不规则形。16S rDNA序列与苏云金芽孢杆菌属的BMB 171同源性达99%,鉴定为苏云金芽孢杆菌,命名为JN002。该菌株对亚洲玉米螟具有较高毒力,对水稻二化螟毒性不及玉米螟,对黏虫几乎无毒力。该菌株是1株对亚洲玉米螟具有较强毒力的苏云金芽孢杆菌新菌株,同时也具备防治水稻二化螟的潜力。     

Plant age effect of rice cultivar IR46 on susceptibility to the yellow stem borer Scirpophaga incertulas (Walker) (Lepidoptera: Pyralidae)

Plant damage and grain yield losses of rice cultivar IR46 under field conditions were highest when attacked by yellow stem borer Scirpophaga incertulas (Walker) larvae in the tillering and flowering stages and lowest when plants were at the panicle initiation stage of growth. A screenhouse tests indicated that S. incertulas development was most rapid on the tillering and flowering stages and lowest on the panicle initiation stage. An action threshold of one egg mass per m² is suggested.