渭北旱塬苹果黑星病流行因子分析

利用渭北旱塬7年(1997～2003年)的温度、相对湿度、降水量和苹果黑星病流行程度资料,采用逐步回归法分析了影响渭北旱塬苹果黑星病流行的因子,求得最优回归子集,包括4月和8月份的降水量、前1年12月份的平均相对湿度、1月和7月份的平均温度,建立苹果黑星病多元线性回归预测模型,以残差绝对值<0．5为统计标准,对1997～2003年苹果黑星病的流行程度进行回测。结果表明,预测模型回测准确率高,可用于指导渭北旱塬苹果黑星病的防治工作。     

重庆市长寿区柑橘黑星病综合防控试验示范

柑橘黑星病是重庆市长寿区柑橘的一个重要病害,在夏橙上尤为严重。为了有效地控制柑橘黑星病的发生和流行,在2016—2017年进行了夏橙黑星病防治的田间试验示范。实施"以加强栽培管理、清洁果园为主,喷药保护为辅"的绿色综合防治措施,有效地控制了黑星病的发生,达到了增产增收的目的。建议:1)引进新品种,鼓励果农进行高接换种。2)引进投资商,将失管果园转包给专业公司管理。3)加强技术培训,将柑橘黑星病综合防治技术标准化,以利加快推广普及。     

苹果锈果类病毒在新疆的发生检测及其序列分析

苹果锈果病一度被认为是病毒病害，直到日本学者Hashimoto等首次报道了ASSVd全序列，才确认为类病毒病害 [4]。苹果锈果类病毒（Apple scar skin viroid，ASSVd）属于Pospiviroidae科，主要侵染苹果和梨[1]，是我国苹果产区的一种重要病害，果树感染后症状主要表现在果实上，随品种和感病阶段不同，有花脸、锈果、裂果、果实变小皱缩等，严重时，整树的果实都不堪食用，失去经济价值[2]。国内早在三十年代对苹果锈果病有报道，但病原一直未定。早在上个世纪五十年代，刘福昌先生对苹果锈果病和梨树的关系[3]，进行了大量的研究，八十年代陈炜等做了大量的研究工作[1，2]，。迄今，苹果锈果病在辽宁、陕西等不同苹果主产区已有报道,但在新疆地区尚未报道，另外，不同地区的锈果类病毒是否同源，也未有相关研究报道。本研究首次对新疆地区苹果锈果=病进行鉴定和序列分析，为该类病毒的同源性分析和防治策略提供依据。     

广东省香蕉主要病害的无公害化防治探究

香蕉是芭蕉科芭蕉属的大型草本植物,是我国较为常见的水果之一,其产地基本分布在广东、云南、海南、福建等地,是一种重要的经济作物。当前,香蕉的病虫害问题严重影响了香蕉的产量与质量,多种病虫害的无公害化防治研究尤为重要。基于此,对广东省香蕉种植过程中出现的束顶病、花叶心腐病、镰刀菌枯萎病、叶斑病、黑星病、线虫病等病害进行分析,根据广东省的实际情况进行无公害化防治探究。     

重庆地区柑橘主要病害及其防治技术要点

柑橘产业已成为三峡库区人民脱贫致富的重要手段,但重庆地区高热多湿的气候特征使得多种柑橘病害发生严重,严重制约着柑橘产业的绿色健康可持续发展。简述在重庆地区发生的柑橘砂皮病、黑星病、炭疽病、疮痂病等4种主要柑橘病害的发生规律及综合防治技术。提出重庆作为全国柑橘主产区,在柑橘病虫害防治方面一定要坚持生态优先、绿色发展理念,主动落实国家"双减行动",积极探索柑橘病虫害生物防治新技术,研发相关试剂产品。     

秦安县矮化苹果园病虫害绿色防控技术初探

甘肃省秦安县矮化密植苹果园主要病害和虫害各有10余种,以苹果腐烂病、二斑叶螨和苹果黄蚜等发生较为严重。对此,通过总结近5年来矮化密植苹果园病虫害防治经验,提出综合农业防治、物理防治、生物防治和化学防治手段为内容的绿色防控技术,以期为创新秦安苹果产业绿色发展模式提供参考。     

基于VenInf模型的梨黑星病侵染测报器的设计

为了能及时预防和有效控制梨黑星病的发生,该文设计了一种能够实时测报梨黑星病菌侵染数量的便携式侵染测报器。该测报器利用STC89C52RC单片机和温湿度智能传感器SHT15作为核心元器件,实现温度和湿度的实时采集,并根据采集的温度和湿度实时计算梨黑星病菌的相对侵染量,根据侵染量实时预警,实现梨黑星病菌侵染的实时预测与预警。该测报器具有操作简单,界面友好,携带方便,性价比高的特点。经试验验证：测报器测报的准确率高,为果农及时用药防治病害提供了科学依据。     

近20年甘肃省苹果4种主要病害发生分析及趋势预测

利用指数平滑法对甘肃省2000-2019年苹果树腐烂病、苹果枝干轮纹病、苹果褐斑病和苹果斑点落叶病4种病害发生程度进行基本趋势分析,并用2020年的发生值进行了验证,预测了2021-2022年的发生趋势,分析了发生程度与发生面积的相关性。结果表明:苹果树腐烂病、苹果枝干轮纹病、苹果褐斑病和苹果斑点落叶病4种主要病害2020年拟合值接近实际,预测在甘肃2021-2022年2年内均呈上升趋势,其中,苹果树腐烂病发病趋势将较缓,其他3种病害的发生将呈较快上升趋势,需加强病害预防和控制。相关分析表明,甘肃省4种苹果主要病害发生程度与发生面积之间无相关性。本研究为指数平滑法短期预测苹果病害提供了理论依据。     

我国主要苹果种质抗黑星病评价

采用涂抹法、浸蘸法、菌饼覆盖法和注射法接种苹果黑星菌分生孢子,确定了适于苹果黑星病菌的涂抹接种法.收集了"秦冠"、"陕富6号"、"嘎啦(丽嘎)"、"红星"、"乔纳金"、"粉红女士"、"金世纪"、"萌"、"太平洋玫瑰"、"澳洲青苹"、"4-1"、"M26"、"MMl06"、"八棱海棠"、"新疆野苹果"等15种苹果种质资源,并对其抗苹果黑星病特性进行鉴定和评价.结果表明,15种苹果种质可被划分为高度抗病品种"新疆野苹果"和"秦冠",中度抗病品种"八棱海棠",中度感病品种"MM106"、"M26"、"乔纳金"、"红星"、"陕富6号"和"丽嘎",高度感病品种"澳洲青苹"、"4-1"、"萌"、"太平洋玫瑰"、"粉红女士"和"金世纪"4类.     

基于迁移学习的苹果落叶病识别与应用

为解决现有卷积神经网络苹果叶片病害识别模型泛化能力弱,模型体积较大等问题,该研究提出一种基于改进MobileNetV3苹果落叶病识别模型。以健康叶片和常见苹果落叶病为研究对象,包括斑点落叶病、灰斑病、褐斑病、锈病4种,每种病害2级,共9类特征,通过改进网络的注意力模块、全连接层及算子,结合迁移学习的训练方式,构建苹果落叶病识别模型。在扩充前后的数据集上对比不同的学习方式、学习率和注意力模块等对模型的影响,验证模型的识别性能。试验结果表明：采用迁移学习的方式,在训练50轮达曲线收敛,比全新学习的准确率增加6.74～10.79个百分点;使用引入的ET(efficient channel attention-tanh)注意力模块,网络损失曲线更加平滑,模型的参数量更少,模型体积减小了48%,提高了模型的泛化能力;在扩充数据集上,学习率为0.000 1时,结合迁移学习的训练方式,改进MobileNetV3(ET3-MobileNetV3)苹果落叶病识别模型,平均准确率能达到95.62%,模型体积6.29 MB。将模型部署到喷药设备上,可实现基于苹果叶片病害识别的变量喷施,该研究可为苹果叶片病害...     

Comparison of Penman-Monteith and non-linear energy balance approaches for estimating leaf wetness duration and apple scab infection

Leaf Wetness Duration (LWD) is the main parameter involved in the apple scab development in apple orchards. LWD values can be inferred from weather conditions by solving a non-linear energy balance equation. Such energy balance equation is usually linearized leading to the Penman-Monteith equations. However this approximation leads to significant errors in the evaporative term and by consequence in the LWD computation. In this work, consequences of the use of the Penman-Monteith equations instead of the exact solution were firstly investigated on single droplets and compared to experimental values obtained in controlled and constant conditions. For these studies, the LWD is overestimated by 12% when Penman-Monteith equations were used. The ability of LWD estimate from the linearized energy balance equation to forecast risk infection of a leaf by V. inaequalis conidia was investigated. For some conditions, the error in LWD estimate by Penman-Monteith approached 6 h, leading to an incorrect risk assessment of apple scab development.     

Evaluation of Malus species and cultivars at the Fruit Genebank Dresden-Pillnitz and its use for apple resistance breeding

Using the results of evaluation of Malus accessions during the last 20 years more than 15 new resistant apple cultivars were selected. The breeding aim was the combination of different kinds of resistance with good fruit quality. The best of these cultivars enclose resistance against Venturia inaequalis, Podosphaera leucotricha, Erwinia amylovora, Pseudomonas syringae, Panonychus ulmi and winterfrost. Different scab resistance sources (Vf, Vr, VA) found among the Malus species are combined in the most recent breeding lines.The new resistant Pillnitz apple cultivars ('Recultivars®') guarantee the possibility to reduce 80% and more of fungicide spraying in fruit growing and are very suitable for ecological and integrated fruit production. Four of these, 'Reanda', 'Rebella', 'Remo' and 'Rewena', are triple resistant to scab, mildew and fire blight and are good donors for breeding multiple resistance.     

First insight into genetic diversity and population structure of the Caucasian wild apple (<Emphasis Type="Italic">Malus orientalis</Emphasis> Uglitzk.) in the Hyrcanian forest (Iran) and its resistance to apple scab and powdery mildew

Investigating population genetic structure and diversity, and resistance to pathogens in crop wild relatives are key steps to assess appropriate conservation and breeding programs. The Caucasian wild apple (Malus orientalis Uglitzk.) is an emblematic fruit tree of the Hyrcanian forest and is supposed to be a contributor to the cultivated apple genome (Malus domestica Borkh. Yet, no study has investigated its population structure, diversity and susceptibility to the two main pathogens of apples, the apple scab (Venturia inaqualis) and the powdery mildew (Podosphaera leucotricha). Here, we investigated population genetic structure and diversity of M. orientalis in the Hyrcanian forest as a mean to identifying future targeted populations for apple conservation and breeding programs. We genotyped using multilocus microsatellite 100 M. orientalis trees sampled in 14 sites. These trees were also screened for presence/absence of six (Rvi6, Vr, Rvi4, Rvi15, Rvi5 and Rvi11) and three (Pl-1, Pl-w, Pl-d) resistance genes to the apple scab and the powdery mildew respectively. Our results showed significant but weak between-site genetic differentiation and isolation by distance pattern suggesting substantial historical gene flow for M. orientalis in this area. We also detected a West-Eastern genetic structure across the Hyrcanian forest with five main populations showing admixture. We also showed a high diversity of resistance genes to apple scab across sites; in contrast, we only found one resistance gene to powdery mildew. These results are a first glimpse to settle wild apple conservation programs in Iran and pinpoint Iranian wild apple populations as an untapped source for apple breeding.     

Chemical characterization of conducive and suppressive soils for potato scab in Hokkaido,Japan

Potato common scab induced by Streptomyces scabies is a serious constraint for potato-producing farmers and the incidence of potato scab depends on the soil chemical properties. We examined the chemical characteristics of conducive and suppressive soils to potato common scab with reference to the chemical properties of nonallophanic Andosols, recently incorporated into the classification system of cultivated soils in Japan. Allophanic Andosols with a ratio of pyrophosphate-extractable aluminum (Al_p) to oxalate-extractable aluminum (Al_o) of less than 0.3–0.4 were “conducive” soils with a high allophane content of more than 3%. On the other hand, nonallophanic Andosols with a Al_p/Al_a ratio higher than this critical value were “suppressive” soils, and their allophane content was less than 2%. The concentration of water-soluble aluminum (AI) was also a useful index for separating conducive from suppressive soils as well as the Al_p/Al_a value and allophane content. The suppressive soils showed a much higher concentration of water-soluble Al at pH 4.5 to 5.5 than the conducive soils. The high concentration of water-soluble Al may be responsible for the control of the incidence of potato common scab in Andosols.     

基于垄间背景剔除优化小麦赤霉病遥感监测精度

为探究麦田垄间背景对无人机多光谱小麦赤霉病监测精度的影响,该研究以江苏省镇江市农科院灌浆期小麦为研究对象,利用大疆M600 Pro无人机搭载RedEdge-MX多光谱相机获取小麦冠层多光谱影像。通过筛选与小麦赤霉病相关性最高的植被指数（vegetation indexes,VIs）：MSR和CRI2植被指数,并采用大津法（Nobuyuki Otsu method,OTSU）、阈值分割法和支持向量机（support vector machine,SVM）等方法对小麦赤霉病遥感图像进行精细化语义分割,降低田块边缘阴影背景和染病麦穗之间的误判率。试验结果表明：目视解译阈值分割法剔除背景的效果最好（总体精度：92.06 %,Kappa系数：0.84）,OTSU阈值分割法（总体精度：90.52%,Kappa系数：0.81）效果次之。采用偏最小二乘回归分别建立小麦病情指数（disease index,DI）与VIs、纹理特征（texture features,TFs）和VIs&TFs小麦赤霉病监测模型,其中VIs&TFs模型监测精度最高,剔除垄间背景前预测模型训练集的决定系数（coefficient of determination,R2）为0.73,均方根误差（root mean square error,RMSE）为5.52,相对分析误差（relative percent deviation,RPD）为2.01,验证集的R2为0.68,RMSE为6.21,RPD为1.96;剔除垄间背景后VIs&TFs模型监测精度依然最高,训练集的R2为0.75,RMSE为5.58,RPD为2.13,验证集的R2为0.77,RMSE为7.13,RPD为2.11。综上所述,基于垄间背景特征的精细化语义分割有效地提高了小麦赤霉病的监测精度,可以直观地了解小麦病情分布情况,可对后续变量施药提供参考依据。     

考虑面源污染的中国苹果全要素生产率及其空间集聚特征分析

利用单元调查方法对苹果产业面源污染进行核算,并将苹果生产带来的面源污染作为苹果的"坏"产出纳入苹果全要素生产率分析框架,进而运用曼奎斯特-卢恩伯格(Malmquist-Luenberger)生产率指数测算1994-2013年环境约束下中国21个省份的苹果全要素生产率及其成分分解,并采用莫兰(Moran’s I)指数分析生产率的空间自相关性。结果表明:环境约束下苹果全要素生产率、技术效率及技术进步率明显小于未考虑环境约束的测算结果,苹果产业发展已经呈现出以污染环境为代价的粗放式增长;中西部地区的苹果产业发展与环境不协调,而东部沿海地区的苹果产业发展与环境较为协调;中国苹果全要素生产率在全域及局域均表现出显著的正向空间相关性,但不同省份苹果全要素生产率在样本期内的空间关联类型变化较为明显。该研究可以为促进中国苹果产业实现环境和产业增长相协调的可持续发展提供意见参考。     

The RAPD evidence for the phylogenetic relationship of the closely related species of cultivated apple

The phylogenetic relationship of cultivated apple and its closely related species is still not clear in the taxonomy of genus Malus. To try to find new evidence for the origin and evolution of the cultivated apple, random amplified polymorphic DNA (RAPD) markers of 14 taxa of Malus, among which a reference species (M. toringoides) and six presumably ancestral species of cultivated apple in the genus were investigated. The RAPD data obtained were used to construct both unrooted and rooted trees using TREECON software package. The result showed in our rooted tree that M. sieversii from the Xinjiang Autonomous Region of China is the species which is most closely related to the cultivated apple, M. domesticacv. `Golden Delicious'. The phylogenetic relationships among the species studied are discussed.     

基于多路卷积神经网络的大田小麦赤霉病图像识别

为了准确地识别小麦病害,及时采取防治措施,减少农药施用的成本,同时减少农业生态环境的污染,该研究以灌浆期感染赤霉病的小麦麦穗图像为研究对象,根据病变区域与健康区域的颜色分布特点,设计了一种多路卷积神经网络用于小麦赤霉病图像的识别。首先利用深度语义分割网络U-Net对大田环境下的小麦图像进行分割,去除小麦叶片及其他无关背景的影响,从而分割出麦穗图像。然后设计结构较为简单的多路卷积神经网络分别提取麦穗图像R、G、B 3个通道的特征,通过特征融合获得具有高辨识性的麦穗图像语义特征。最后,为了增大赤霉病和健康麦穗图像特征之间的可区分性,同时减小赤霉病麦穗图像类内特征的差异,采用联合损失函数进一步改善网络的性能。该研究对采集的大田环境下的510幅灌浆期小麦群体图像进行分割,选取2 745幅完整单株麦穗图像利用所设计的多路卷积神经网络进行赤霉病识别试验,结果表明该研究所提算法对单株麦穗赤霉病识别精度达到100%,能够为小麦病害的智能识别提供帮助。     

沙地濒危植物长柄扁桃生物学特性与抗逆性及应用综述

揭示长柄扁桃生物学特性与抗逆性机理并提高其在荒漠化治理中的生态效益和经济效益,是实现西北旱区荒漠化治理可持续发展和提升生态脆弱区生态系统服务功能面临的重要科学问题。本文回顾了长柄扁桃研究所取得的进展,包括建立了长柄扁桃快速育苗和无灌溉水栽培技术,揭示了不同地区长柄扁桃生长规律及其对逆境的适应性,推进了长柄扁桃在荒漠化治理中的应用及其产品开发等;在此基础上,提出了长柄扁桃研究面临的机遇和挑战,包括长柄扁桃的适生土壤类型与耗水量,不同地区长柄扁桃的合理种植密度及其调控和管理措施,长柄扁桃抗逆性机理及其产品开发与高值综合利用等,以期为我国在西北地区推广和建设长柄扁桃林、优化水土资源管理和提高脆弱生态系统的服务功能提供科学依据。