Reclassification of an isolate of Guignardia citricarpa from New Zealand as Guignardia mangiferae by sequence analysis   总被引：3，自引：0，他引：3  

K. R. Everett  J. Rees-George 《Plant pathology》2006,55(2):194-199

Citrus black spot was recorded as present in New Zealand in international databases on the basis of one isolate (ICMP 8336) identified by morphological features as Guignardia citricarpa . This isolate was from a soft rot, not a typical symptom of citrus black spot, on a Seminole tangerine fruit grown in the northern region of New Zealand. Sequence analysis of the internal transcribed spacer (ITS) region (ITS1, 5·8S and ITS2) showed that this isolate was 99% identical to the ITS region of G. mangiferae , a closely related saprotroph. Despite climatic conditions being suitable for this disease, citrus black spot symptoms have never been seen on citrus fruits grown in New Zealand. Thus the absence of symptoms on citrus in New Zealand is probably because G. citricarpa is not present. On the basis of these results, the record of citrus black spot occurring in New Zealand should be re-examined.  相似文献   

Use of airborne multispectral imagery to discriminate and map weed infestations in a citrus orchard     

XUJUN YE  KENSHI SAKAI  SHIN-ICHI ASADA  AKIRA SASAO 《Weed Biology and Management》2007,7(1):23-30

Reliable information on weed abundance and distribution within fields is essential for weed management in agricultural systems. Such information is necessary to adopt localized and variable rates of herbicide spraying, thus reducing chemical waste, crop damage, and environmental pollution. This paper examined the potential of airborne multispectral imagery to discriminate and map weed infestations in an experimental citrus orchard in Japan. Using an airborne digital sensor, multispectral imagery was acquired over the study site on 10 April 2003. The obtained reflectance imagery was analyzed using an image object-based approach in eCognition. After creating image objects on the image, the spectral information for weeds and citrus, represented by corresponding selected sample image objects, was extracted. Significant differences in the spectral characteristics between weeds and citrus were observed in each of the red, green, and blue wavebands. The simple average values of these wavebands were used to classify image objects with the nearest neighbor algorithm. Maps were generated with different classes or levels of class groups. A subsequent accuracy assessment demonstrated that the weeds were successfully discriminated from other image objects with a classification accuracy of 99.07%. Therefore, maps generated based on the classification result could provide valuable information for developing a site-specific weed management program for the study orchard.  相似文献   

A rapid chronometric assay of peroxidase activity in citrus leaf discs     

A. Torrecillas  A. Leon  F. Del Amor  M.C. Martinez-Mompean 《Scientia Horticulturae》1985,26(3):273-277

A rapid peroxidase assay is proposed, using 3-mm diameter leaf discs, and based on the chronometric measurement of the oxidation of ascorbic acid, which is detected by means of the appearance of the blue colour of the benzidine-coupled reaction.The proposed method is adequately reproducible and sensitive for the diagnosis of iron deficiency in citrus.  相似文献   

发酵柑桔渣取代麦麸饲育肥猪试验     

程建华  王舜华  史海林  张清纯  夏时福  胡友前 《粮食储藏》1999,(4)

柑桔渣经微生物发酵后烘干，以１０％～１５％比例取代麦麸添加到猪日粮中 饲喂育肥猪。饲料适口性良好，对猪的采食和增重均无影响。猪只经屠宰解剖表明，发酵 柑桔渣作猪饲料无任何毒副作用。具有明显的经济效益和社会效益。  相似文献   

Regeneration and molecular characterization of interspecific somatic hybrids between Satsuma mandarin and two seedy sweet oranges for scion improvement     

X. D. Cai  W. W. Guo 《Plant Breeding》2011,130(2):287-290

  相似文献   

柑橘衰退病毒柚类分离物CP基因的克隆及原核表达分析     

王彩霞 《青岛农业大学学报(自然科学版)》2009,26(2):139-142

以来自湖北省的HB柚柑橘衰退病毒(Citrus tristeza virus,CTV)分离物(CTV-HB1)为材料,利用RT-PCR技术对其CP基因进行克隆,序列分析结果表明:CTV-HB1与典型茎陷点分离物SY568和NUagA的核苷酸和推定氨基酸的序列相似性均在97%以上,而与CTV速衰分离物T36和弱毒分离物T385和T30的核苷酸和氨基酸序列相似性较低,均在95%以下。将CP基因片段连接到表达载体,转化大肠杆菌后诱导重组蛋白的表达。SDS-PAGE和Westen-blot分析结果表明,经IPTG诱导后产生了预期大小的重组蛋白,该蛋白可与CTV-L5提纯病毒制备的多克隆抗体发生特异性免疫反应。  相似文献   

柑橘类植物精油的抗菌活性及其作用机制   总被引：1，自引：0，他引：1  

张卓  聂德超  赵琛  李艳玲 《动物营养学报》2022,34(2):758-764

柑橘类植物精油(CEOs)是从柑橘类植物中提取的芳香类混合物,其主要活性成分为D-柠檬烯(D?limonene),具有广泛的生物活性,包括抗菌、抗氧化和抗炎等.CEOs具有选择性抗菌活性,在动物生产中具有非常重要的应用价值.不同的CEOs具有不同的抗菌活性,研究其抗菌机制也具有非常重要的意义.本文着重介绍了CEOs的化...  相似文献   

基于适宜概率模型的柑橘生产空间模拟变化     

林正雨  陈春燕  刘远利  高文波  曹杰  刘光辉  廖桂堂  何鹏 《农业现代化研究》2022,43(4):726-737

土地利用/土地覆被变化模拟是土地科学的重要内容。随着全球变化研究的不断深入,LUCC变化模拟已逐步深入到农作物空间。开展长时序农作物空间变化模拟有助于揭示农业生产过程中“人类-自然”综合体的复杂关系。然而目前农作物空间模拟研究较少,已有模型在空间映射关系,对象识别等尚存技术局限,模型应用也主要集中在粮食作物。本文构建了基于适宜概率的柑橘生产空间分配模型,对四川省柑橘生产空间分布进行了模拟研究。结果显示：该模型较好地反映了1980—2015年柑橘统计特征,各时期统计面积和模拟面积的相对误差均＜25%。在县域尺度上,统计面积和模拟面积的相关系数在0.987 6~0.999 9,呈现明显的线性相关,达到了极显著相关。1980—2015年间,四川省柑橘空间快速扩张,柑橘模拟面积的时序变化与统计面积一致。柑橘空间集中在川中丘陵区和成都平原区。空间格局从分散零星向区域集聚转变,大致形成了成都平原、川南、川东北3个柑橘集中区。SPAM-Citrus模型误差受空间分辨率、空间分配规则、土地覆被、作物分布点的共同影响。在应用中应尽量选择种植年限较长的采样点,同时面向研究对象和区域,选择合适分辨率和空间分配规则,提高预测结果的准确性。  相似文献   

极端低温对晚熟柑桔产业的影响及冻后补救措施     

杨贵川  冉晶  黎德富  何震  陈品文  蒲成伟  周立  吴小平  袁佳阳  何思乐 《现代农业科技》2021,20(20)

2020年冬季的极端低温天气对全国晚熟柑桔产业造成了较为严重的影响。为将冻害损失降至最低程度,以南充地区为例,通过实地调查、分析对比冻害发生情况,提出了晚熟柑桔冻害发生后的补救措施,为促进南充及相似产区晚熟柑桔产业有序恢复及后续发展提供参考。  相似文献   

基于日光诱导叶绿素荧光的柑橘黄龙病原位诊断     

陈硕博  沈煜韬  谢鹏尧  陆旭琦  何勇  岑海燕 《农业工程学报》2022,38(9):324-332

柑橘黄龙病（Huanglongbing, HLB）是柑橘生产中的毁灭性病害,柑橘植株遭到黄龙病菌侵染后光合能力发生变化而后表现出相应的黄化症状。及早实现HLB的原位快速诊断是防控HLB的重要手段。为探究黄龙病菌侵染柑橘叶片的光合响应机制并实现HLB的原位诊断,该研究分析了健康（Healthy）、未显症HLB（asymptomatic HLB, aHLB）、显症HLB（symptomatic HLB, sHLB）以及黄斑病（Macular,症状与黄龙病相似）柑橘叶片的光合参数与光合色素含量差异。利用光谱技术与日光诱导叶绿素荧光（Sun-induced Chlorophyll Fluorescence, SIF）技术分析了4种类型柑橘叶片的反射率光谱与SIF光谱差异。采用竞争自适应重加权采样（Competitive Adaptive Reweighted Sampling, CARS）算法结合反射率光谱筛选出特征波段,采用SIF光谱的峰值位置（687和741 nm）构建了上行（Upward, Up）和下行（Downward, Dw）SIF产量指数（Up687, Up741, Dw687, Dw741, Up687/741, Dw687/741）。进一步分别利用特征波段的反射率和SIF产量指数,结合K最邻近（K-nearest Neighbor, KNN）分类算法构建了柑橘黄龙病的诊断模型。结果表明,黄龙病菌的侵染使柑橘叶片的光合作用明显减弱,在未显症时期已经表现出来,证明了SIF技术在诊断早期HLB的优势。基于特征波段反射率的KNN模型对未显症HLB和显症HLB的诊断精度为72.7%和75.6%,健康叶片和黄斑病叶片分别为82.2%和64.1%,而基于687和741 nm波长处的上行比值SIF产量指数Up687/741构建的KNN模型对未显症HLB和显症HLB的诊断精度为84.8%和91.1%,健康和黄斑病叶片分别为88.9%和82.1%,均优于反射率光谱模型。结果证明了SIF技术用于诊断柑橘HLB的潜力,为实现柑橘HLB的田间原位、快速、早期诊断提供了可能。  相似文献