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检疫性杂草糙果苋（Amaranthus tuberculatus）与同属其他种的鉴别一直是个难点。本研究建立糙果苋的KASP(Kompetitive allele-specific PCR)检测方法,可用于糙果苋快速、准确的分子鉴定。提取11种23份苋属植物的DNA后,根据长芒苋（Amaranthus palmeri）核基因组序列,设计引物AP4F和AP4R,通过序列扩增和比对,发现糙果苋有特异性SNP (Single nucleotide polymorphism)位点。利用引物设计软件Primer 5设计了用于鉴定糙果苋的KASP反应引物。结果表明,特异引物基于KASP技术扩增后,可以形成明显的基因分型,能将糙果苋与同属近缘种进行区分。该研究为进口粮谷中糙果苋的检测鉴定提供了新技术。 相似文献
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风媒传播是外来杂草传播扩散的主要途径之一。我国进口粮谷中经常携带大量苋属杂草种子,这些种子质量轻,在卸货、运输等过程中存在风传播扩散风险。本文以3种重要苋属检疫性杂草,即长芒苋、西部苋和糙果苋种子为材料,通过测定其在可能撒漏高度范围和撒漏点风速范围内的垂直沉降速度和水平扩散距离,预测苋属3种检疫性杂草在装卸及运输过程中风传播扩散范围。结果表明在风速为35 m/s,种子释放高度为35 m时,长芒苋、西部苋和糙果苋3种杂草种子的最远扩散距离分别为57.75 m、111.68 m和114.33 m。 相似文献
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通过对北疆、东疆杂草的野外实地调查,利用《中国植物志》等相关资料和形态分类学研究方法,本团队在阿勒泰、伊犁、昌吉、塔城和哈密等地区发现苋属Amaranthus外来杂草新记录植物4种。本研究发现,新疆苋属Amaranthus 3个新记录种和1个新记录变种,即绿穗苋Amaranthus hybridus L.、鲍氏苋A. powellii S. Watson、皱果苋A.viridis L.和短苞反枝苋A. retroflexus L. var. delilei (Richter&Loret) Thell.。绿穗苋在伊犁新源县、乌鲁木齐市、哈密市均有小居群分布;皱果苋在乌苏车排子垦区、吐鲁番市高昌区、哈密市伊州区等地有多个居群分布;鲍氏苋仅在哈密市巴里坤县有分布;短苞反枝苋仅在石河子市有少量分布。这些新记录植物的发现对新疆苋科苋属植物区系和物种多样性研究具有重要意义,也为该新记录种的地理分布研究、入侵杂草的扩散与有效监测提供了重要依据和新资料。 相似文献
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Suspected imazaquin-resistant accessions of Amaranthus palmeri were studied to determine the magnitude of resistance and cross-resistance to acetolactate synthase (ALS)-inhibiting herbicides and compare differential tolerance of A palmeri and Amaranthus hybridus to ALS inhibitors. Five of seven A palmeri accessions were resistant to imazaquin. The most imazaquin-resistant accession, accession 7, also showed 74, 39 and 117 times higher resistance than the susceptible biotype to chlorimuron, diclosulam and pyrithiobac, respectively. Resistance to imazaquin and cross-resistance to other ALS inhibitors in A palmeri was due to a less-sensitive ALS enzyme. A palmeri was 70 times more tolerant to imazaquin than A hybridus. A palmeri was also seven times more tolerant to pyrithiobac than A hybridus. Differences in ALS enzyme sensitivity could not fully account for the high tolerance of A palmeri to imazaquin compared to A hybridus. Both species were equally affected by chlorimuron and diclosulam. 相似文献
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外来入侵植物长芒苋Amaranthus palmeri已经传入我国多个地区,定量评估其入侵风险对制定高效防控措施具有重要意义。外来植物入侵风险应该是由传入后能发芽并完成生活史的繁殖体如种子的量决定的,但已开展的适生区预测等风险评估通常忽略了该因素。基于此,本研究先通过同质园试验, 比较了采自我国不同纬度的11个长芒苋种群与来自原产地美国种群的种子发芽率,分析了种群间发芽率的差异及其与纬度的相关性;然后,通过一年内连续多次在不同纬度地区的交互种植试验,分析了不同纬度种群间种子的发芽率和完成生活史的入侵窗口期差异,并判断是否发生了本地适应;最后,根据发芽率和入侵窗口期评估了长芒苋在我国不同纬度地区的入侵风险。同质园试验表明,种子发芽率与种群所处纬度显著正相关(P<0.05),发芽率随纬度升高而增高。交互种植试验表明,不同种群发芽率的差异是由于本地适应导致的,长芒苋在我国的入侵窗口期随纬度升高而缩短。基于不同种群种子发芽率和入侵窗口期的纬度差异,我们判断长芒苋在我国中低纬度至中高纬度区域内入侵风险较高,应该重点防控。长芒苋在高纬度和低纬度地区的入侵风险相对较低。但长芒苋种子萌发的本地适应可能会增加其在高、低纬度地区的入侵风险。因此,亟须加强对已传入种群的监测预警与早期防控力度,抑制其繁殖增长和进一步的扩散蔓延。 相似文献
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Powles SB 《Pest management science》2008,64(4):360-365
Glyphosate is the world's most important herbicide, with many uses that deliver effective and sustained control of a wide spectrum of unwanted (weedy) plant species. Until recently there were relatively few reports of weedy plant species evolving resistance to glyphosate. Since 1996, the advent and subsequent high adoption of transgenic glyphosate-resistant crops in the Americas has meant unprecedented and often exclusive use of glyphosate for weed control over very large areas. Consequently, in regions of the USA where transgenic glyphosate-resistant crops dominate, there are now evolved glyphosate-resistant populations of the economically damaging weed species Ambrosia artemissifolia L., Ambrosia trifida L., Amaranthus palmeri S Watson, Amaranthus rudis JD Sauer, Amaranthus tuberculatus (Moq) JD Sauer and various Conyza and Lolium spp. Likewise, in areas of transgenic glyphosate-resistant crops in Argentina and Brazil, there are now evolved glyphosate-resistant populations of Sorghum halepense (L.) Pers and Euphorbia heterophylla L. respectively. As transgenic glyphosate-resistant crops will remain very popular with producers, it is anticipated that glyphosate-resistant biotypes of other prominent weed species will evolve over the next few years. Therefore, evolved glyphosate-resistant weeds are a major risk for the continued success of glyphosate and transgenic glyphosate-resistant crops. However, glyphosate-resistant weeds are not yet a problem in many parts of the world, and lessons can be learnt and actions taken to achieve glyphosate sustainability. A major lesson is that maintenance of diversity in weed management systems is crucial for glyphosate to be sustainable. Glyphosate is essential for present and future world food production, and action to secure its sustainability for future generations is a global imperative. 相似文献
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While surveying Illinois Amaranthus tuberculatus (Moq) Sauer (tall waterhemp) half-sib populations for herbicide response variability, several were observed to segregate for resistance to atrazine. Studies were conducted on greenhouse-grown A tuberculatus plants to compare atrazine responses among populations that were segregating for resistance (SegR), uniformly sensitive (UniS) or uniformly resistant (UniR). In chlorophyll fluorescence assays, leaves of plants from the SegR and UniS populations displayed changes in fluorescence after treatment with atrazine, indicating that atrazine was inhibiting electron transport of photosystem II in chloroplasts. Sequencing of a fragment of psbA, which encodes the D1 protein, revealed that the SegR population did not contain the amino acid substitution that is typically found in triazine-resistant plants. Whole-plant herbicide dose-response experiments revealed that, relative to the UniS population, atrazine resistances in the UniR and SegR populations were > 770-fold and 16-fold, respectively. The SegR population was also resistant to cyanazine (59-fold), but not to metribuzin, linuron or pyridate. Triazine resistance in the SegR population was shown to be a nuclear inherited trait, unlike maternal inheritance of site-of-action mediated triazine resistance found in the UniR population. Taken collectively, these findings confirm the existence of two distinct triazine resistance mechanisms in A tuberculatus. 相似文献
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恶性入侵杂草长芒苋Amaranthus palmeri S.Watson对农业生产和生物多样性造成严重威胁。预测其潜在适生区对粮食安全和生物多样性保护至关重要。不同模型由于算法不同对长芒苋潜在适生区的预测结果存在差异。本研究综合4种生态位模型(MaxEnt、GARP、BIOCLIM和DOMAIN)预测长芒苋在我国的潜在适生区以提高预测准确性。结果表明,4种模型的平均AUC值均大于0.85。MaxEnt和DOMAIN的平均Kappa值大于0.81;BIOCLIM和GARP的平均Kappa值大于0.69。MaxEnt的预测精度和稳定性要略胜一筹。BIOCLIM和MaxEnt的预测结果较为收敛,DOMAIN和GARP预测的适生区范围较广,由此预测的长芒苋潜在适生区分别占我国陆地总面积的20.66%和32.38%,48.39%和49.76%。综合预测结果,长芒苋在我国的适生区主要集中在中东部地区,西北和东北地区则是长芒苋存在的边缘环境地区。 相似文献
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Midwest USA farmers have reported inconsistent control of Amaranthus tuberculatus (= rudis) (Moq ex DC) JD Sauer by glyphosate in glyphosate-resistant crops. The potential of selection for decreased A tuberculatus sensitivity to glyphosate was therefore investigated in a reportedly resistant Everly, IA population (P0-EV). Evaluation of six A tuberculatus populations from the Midwest USA estimated a seedling baseline sensitivity of 2.15 mM glyphosate. Based on these results, three generations of divergent recurrent selection were implemented on P0-EV to isolate resistant and susceptible populations. A seedling assay was developed to screen large amounts of seeds and thus expedite the selection process. Whole-plant and seedling rate responses of P0-EV and a known pristine A tuberculatus population from Paint Creek, OH (P0-WT) identified no significant difference in response to glyphosate; however, greater phenotypic variance was ostensibly evident in P0-EV. The first recurrent generation selected for resistance at 3.2 mM glyphosate (RS1-R) had a 5.9- and 1.7-fold resistance increase at the seedling and whole-plant levels, respectively, compared with the susceptible generation selected at 32 microM glyphosate. After three cycles of recurrent selection, 14.6-fold difference in resistance at the seedling level and 3.1-fold difference at the whole-plant level were observed when comparing the populations selected for resistance (RS3-R) and susceptibility (RS3-S). Overall, recurrent selection increased the frequency of resistant individuals and decreased the variability to glyphosate at the population level. Nevertheless, variability for glyphosate resistance was still evident in RS3-R. Results herein suggested that A tuberculatus is inherently variable to glyphosate and that selection decreased the sensitivity to glyphosate. We purport that evolved glyphosate resistance in A tuberculatus may require multiple cycles of selection under field conditions. Historic estimated use of glyphosate alludes to the evolution of tolerant weed populations. 相似文献
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长芒苋(Amaranthus palmeri)是近年来入侵我国的超级杂草,已在我国从南到北的多个点定殖,一旦大面积扩散势必会对农业生产和生物多样性保护等构成极大威胁。长芒苋在我国入侵点的纬度跨度大于其原产地北美洲的分布,探明其在我国不同纬度的地理种群的环境适应机制,对评估扩散潜能、建立早期监测预警等防控措施具有重要意义。本研究在同质种植园实验条件下,通过测定长芒苋不同纬度地理种群的生活史、形态及生物量等11个性状指标来分析其在我国的表型变异与环境适应性。结果表明,在同质园条件下,长芒苋不同地理种群间株高等7个表型性状指标差异不显著,而开花和发芽时间、花序长以及比叶鲜重4个指标具有显著差异(p<0.01),且它们的表型变异随年平均温度(纬度)线性增加或降低。开花时间随纬度的升高而缩短,发芽时间、花序长和比叶鲜重随纬度的升高而增加。基于长芒苋不同纬度地理种群间表型性状的异同,我们推断表型可塑性促进了其在我国不同地理环境中的定殖,表型变异(如高纬度种群开花时间提前)可促进其环境适应性进化,拓展其在我国的适生性分布区,增强其向原产地适应环境梯度之外地区入侵和扩散蔓延的潜力。 相似文献