国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁(yè)> 外文學(xué)位 >Responses of rotation-resistant and rotation-susceptible populations of the western corn rootworm to transgenic corn expressing cry toxins and validation of a damage function for corn rootworm larvae.
【24h】

Responses of rotation-resistant and rotation-susceptible populations of the western corn rootworm to transgenic corn expressing cry toxins and validation of a damage function for corn rootworm larvae.

機(jī)譯：西部玉米根蟲的抗旋轉(zhuǎn)和易感種群對(duì)表達(dá)哭泣毒素的轉(zhuǎn)基因玉米的反應(yīng)以及對(duì)玉米根蟲幼蟲損害功能的驗(yàn)證。

獲取原文
獲取原文并翻譯 | 示例
  • 摘要
  • 著錄項(xiàng)
  • 相似文獻(xiàn)
  • 相關(guān)主題

摘要

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a significant insect pest of corn, Zea mays L. Yield losses and control costs associated with the corn rootworm complex---which includes the northern (Diabrotica barberi Smith & Lawrence) and southern (Diabrotica undecimpunctata howardi Barber) corn rootworms as well---exceed an estimated ;The primary goal of the multi-year, multi-state field experiment described in Chapter 2 was to determine if rotation-resistant and rotation-susceptible western corn rootworm larvae differ in their ability to injure transgenic Bt corn roots and cause yield loss. A second goal was to determine if these two populations exhibit differences in emergence or fitness when exposed to Bt corn. A variety of response variables were analyzed, including root injury and yields, as well as cumulative beetle emergence, sex ratios, head capsule widths, and weights. Densities of western corn rootworm beetles were quite low at many of the sites during this experiment. As a result, consistent trends related to root injury and fitness measurements for beetles were difficult to detect. The lack of statistical separation among the various locations and treatments evaluated indicates that many of the variables analyzed are of limited usefulness when densities of western corn rootworm beetles are minimal.;The goal of the greenhouse experiment described in Chapter 3 was to determine if rotation-resistant and rotation-susceptible western corn rootworm larvae differ with respect to survival or development on corn expressing one or more Bt toxins---a single-plant bioassay was used. Corn plants were infested with 225 near-hatch eggs at the V5 growth stage (five leaf collar). Larvae were allowed to develop undisturbed on the root systems for 17 d, after which they were recovered using Berlese funnels. Larvae were counted to estimate mortality; head capsule widths were recorded to assess development. No difference between rotation-resistant and rotationsusceptible larvae with respect to mortality caused by exposure to Bt toxins was observed. Head capsule widths suggest that larvae from these two populations develop similarly when reared on Bt corn. Potential explanations for the observed results are discussed.;An analysis of readily available field trial data used to validate an existing damage function for corn rootworm larvae is reported in Chapter 4. A nested error component model with unbalanced panel data spanning 19 location-years was used to describe the relationship between yield loss and root injury. The model suggests that for each node of roots injured by larvae, a yield loss of approximately 15% is expected. Statistically significant sources of variation included location and experimental error. Variation in weather across sites was likely the principal factor contributing to the significant effect of location. The large experimental error highlights the limitations of using a multi-year, geographically diverse damage function for predicting yield loss on a small scale. Major factors contributing to the variance components estimated by this model are discussed, and techniques for improving future analyses of the damage function for corn rootworm larvae are suggested.
機(jī)譯：西部玉米根蟲Diabrotica virgifera virgifera LeConte（鞘翅目：菊科）是玉米（Zea mays L）的重要玉米害蟲。與玉米根蟲復(fù)合物相關(guān)的產(chǎn)量損失和控制成本-包括北部（Diabrotica barberi Smith＆勞倫斯）和南部（Diabrotica undecimpunctata howardi Barber）玉米根蟲也超過了估計(jì)值;第2章所述的多年多州田間試驗(yàn)的主要目標(biāo)是確定旋轉(zhuǎn)阻力和旋轉(zhuǎn)敏感性西部玉米根蟲幼蟲在傷害轉(zhuǎn)基因Bt玉米根和造成產(chǎn)量損失方面的能力不同。第二個(gè)目標(biāo)是確定當(dāng)暴露于Bt玉米時(shí)，這兩個(gè)種群是否表現(xiàn)出出苗或適應(yīng)性差異。分析了各種響應(yīng)變量，包括根部損傷和產(chǎn)量，甲蟲累積出苗率，性別比，頭囊寬度和體重。在此實(shí)驗(yàn)中，許多地方的西部玉米根蟲甲蟲的密度都非常低。結(jié)果，難以檢測(cè)到與根部損傷和甲蟲適應(yīng)性測(cè)量有關(guān)的一致趨勢(shì)。在不同的位置和所評(píng)估的處理方法之間缺乏統(tǒng)計(jì)分離，表明當(dāng)西部玉米根蟲甲蟲的密度最小時(shí)，所分析的許多變量的作用有限。;第3章所述的溫室試驗(yàn)的目的是確定是否輪作-抗性和易感性的西部玉米根蟲幼蟲在表達(dá)一種或多種Bt毒素的玉米的存活或發(fā)育方面有所不同-使用了一種單植物生物測(cè)定法。在V5生長(zhǎng)階段（五葉領(lǐng)），玉米植物受到225個(gè)近孵化的卵侵?jǐn)_。允許幼蟲在根系上不受干擾地發(fā)育17 d，然后使用Berlese漏斗將其恢復(fù)。計(jì)數(shù)幼蟲以估計(jì)死亡率；記錄頭囊寬度以評(píng)估發(fā)育。對(duì)于因接觸Bt毒素引起的死亡率，抗旋轉(zhuǎn)幼蟲和旋轉(zhuǎn)敏感幼蟲之間沒有差異。頭囊寬度表明，當(dāng)在Bt玉米上飼養(yǎng)時(shí)，這兩個(gè)種群的幼蟲發(fā)育相似。討論了觀察結(jié)果的潛在解釋。;第4章報(bào)告了一種用于驗(yàn)證玉米根蟲幼蟲現(xiàn)有損害功能的現(xiàn)成現(xiàn)場(chǎng)試驗(yàn)數(shù)據(jù)的分析。該誤差嵌套模型的不平衡面板數(shù)據(jù)跨越19個(gè)位置年。用來描述產(chǎn)量損失與根部傷害之間的關(guān)系。該模型表明，對(duì)于受幼蟲傷害的根的每個(gè)節(jié)點(diǎn)，預(yù)計(jì)產(chǎn)量損失約為15％。具有統(tǒng)計(jì)學(xué)意義的變異來源包括位置和實(shí)驗(yàn)誤差。站點(diǎn)之間天氣的變化可能是造成位置顯著影響的主要因素。大的實(shí)驗(yàn)誤差凸顯了使用多年，地理上不同的損害函數(shù)來小規(guī)模預(yù)測(cè)產(chǎn)量損失的局限性。討論了影響該模型估算方差成分的主要因素，并提出了改進(jìn)玉米根蟲幼蟲損害功能的未來分析技術(shù)。

著錄項(xiàng)

  • 作者

    Tinsley, Nicholas Andrew.;

  • 作者單位

    University of Illinois at Urbana-Champaign.;

  • 授予單位 University of Illinois at Urbana-Champaign.;
  • 學(xué)科 Agriculture Agronomy.;Biology Entomology.
  • 學(xué)位 Ph.D.
  • 年度 2013
  • 頁(yè)碼 121 p.
  • 總頁(yè)數(shù) 121
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類
  • 關(guān)鍵詞

相似文獻(xiàn)

  • 外文文獻(xiàn)
  • 中文文獻(xiàn)
  • 專利
獲取原文

客服郵箱：kefu@zhangqiaokeyan.com

京公網(wǎng)安備：11010802029741號(hào) ICP備案號(hào)：京ICP備15016152號(hào)-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有

  • 客服微信

  • 服務(wù)號(hào)