大麦籽粒黑胚病对发芽和幼苗生长的影响研究初报

大麦籽粒黑胚病是大麦根腐病在种子上的一种症状表现。它主要由麦根腐离蠕孢菌(Bipolaris sorokiniana)在大麦灌浆期侵染，引起籽粒胚部变黑。正常年份，感病品种的黑胚率在10％左右。若收获期间遇雨，黑胚率可达30％以上。该病害可导致大麦酿造品质的下降，影响播种质量。     

油梨根腐病发病规律及防治技术

油梨根腐病是油梨根部重要病害，近年来逐渐增多，严重时可造成油梨整株死亡，已成为油梨产业发展的重要病害。目前广西已发现有4种油梨根腐病，是较难防治的土传病害。重点介绍4种油梨根腐病的特点、发生、病因、症状等，从农业、物理、生物、化学防治方面介绍油梨根腐病的防治技术。     

北美大麦品种在黑龙江的研究和利用

引进的北美大麦品种在黑龙江春插，多棱大麦表现为熟期适宜，产量高，酿造品质好，抗倒伏，较抗根腐病，条纹病，适应性强，是生产上的主栽品种，二棱大麦表现品质好，分蘖力强，丰产性好，但熟期偏晚，秆软，叶部病害重，多作为杂交育种中的亲本。利用北美大麦品种进行杂交选育的新品种也不断出现，分析探讨了引种成功原因及今后利用途径。     

黑龙江省大豆根腐病的危害与防治

黑龙江省大豆根腐病的危害与防治黑龙江省农科院大豆所张玉华大豆根腐病是世界各大豆产区的重要病害之一，一般减产１０％，如果和其他根部病害混合侵染，则危害更重。一、大豆根腐病的发生与危害大豆根腐病分布广、危害严重，是我省目前应引起高度重视的主要病害之一。据...     

大麦黑粉菌研究进展

大麦黑粉菌呈世界范围分布,是大麦生产中的主要病害之一,可造成严重经济损失,但在中医上又具有药用和食用价值。本文主要介绍大麦黑粉菌的分类及生理特性,大麦黑粉菌与寄主大麦的互作及其侵染机理,大麦黑粉菌的药用和食用价值,大麦黑粉菌转基因技术体系建立和大麦黑粉菌基因组研究的进展。     

大麦种质资源苗期根腐病抗性鉴定

试验采用孢子悬浮液喷雾接种法,对国内外205份大麦种质资源材料进行实验室苗期根腐病抗性筛选、鉴定。结果表明,有11份材料高抗根腐病,35份材料中抗根腐病,156份材料中感或高感根腐病;以发病严重度为分析变量做品种抗病性聚类分析,取欧式距离为2.14时,品种抗病性可分为两大类,第一类抗病材料(包括高抗与中抗)总共有46份,占供试鉴定材料的22.44%;第二类感病材料(包括中感与高感)总共有156份,占供试鉴定材料的77.09%;获得的抗病材料可作为抗病育种亲本材料,为丰富和拓展我国大麦抗病育种种质资源奠定基础。     

人参土传病害药剂敏感性研究

人参是长白山道地的名贵中药材,土传病害在人工种植中严重影响其产量及品质,为解决这一实际问题,采用生长速率法比较人参枯萎病、立枯病、根腐病等3种土传病害病原菌对百菌清、多菌灵等农药的敏感性。结果表明:代森锰锌对枯萎病、立枯病、根腐病这3种土传病害病原菌的抑制效果最强,百菌清、甲托和多菌灵对3种土传病害病原菌抑制效果不明显。因此,1:700倍液的代森锰锌可用于人参土传病害的防治。     

解决大豆疫霉根腐病的有效途径——转基因育种

大豆是世界上重要的粮食和油料作物,在人类的生产、生活中有着举足轻重的作用。大豆疫霉根腐病是大豆生产中常见的病害,严重影响了大豆的产量和品质。本文对大豆疫霉根腐病的病害症状以及利用转基因技术防治大豆疫霉根腐病的进展进行概述,并对大豆抗病转基因育种的前景进行了展望。     

春小麦抗根腐病的遗传 第一报:Скала品种的单体遗传分析

根腐病是禾谷类作物广泛传播的疾病,它是田聚积在土壤里以及保存在种皮或种子内部的各种不同种真菌引起的。耕作土壤中的微生物,有的对植物无关紧要;有的对植物有利;还有的可引起人们经常防治的病害。植物根的分泌物对土壤微生物区系有一定影响,已经证明抗根腐病和感根腐病的品种,对土壤微生物     

河南省大麦主要病害的发生及防治

大麦生产过程中各种病害时有发生,特别是黑穗病、条纹病、白粉病、纹枯病、赤霉病等.这几种病害发生普遍,已经成为严重影响河南省大麦高产稳产的主要因素.因此,加强病害防治迫在眉睫,是我们广大科技工作者亟待解决的问题.     

青稞全蚀病和根腐病生防毛壳菌的筛选及鉴定

青稞根腐病与青稞全蚀病是西藏青稞的常见根部病害,为筛选适合于防治青稞全蚀病与根腐病的毛壳菌,通过皿内拮抗试验、发酵粗提物抑菌试验和温室盆栽防效试验对4株毛壳菌的抑菌活性进行了鉴定,通过形态学和分子生物学方法对高活性菌株进行了鉴定。结果发现,在皿内拮抗试验中,毛壳菌41-4在培养第7天至第9天时,对青稞根腐病和全蚀病的抑制率分别达到60.00%和44.44%,抑菌带宽度均达到1.4cm。培养7d时毛壳菌41-4发酵粗提物对青稞根腐病和全蚀病的抑制率分别达到64.44%和60.00%,抑菌带宽度均达到1.5cm。在温室盆栽防效试验中,毛壳菌41-4对青稞根腐病和全蚀病的发病严重度和病情指数均有降低作用,防效分别达到62.67%和39.45%。结合形态学特征和核糖体基因内转录间隔区(rDNAITS)序列构建系统发育树,将菌株41-4鉴定为球毛壳菌Chaetomium globosum。该生防菌株可用于开发微生物菌肥,对西藏的无公害农业生产和保护西藏的原生态具有重要意义。     

青稞镰孢根腐病病原鉴定及致病性分析

为明确青稞镰孢根腐病的病原,于青稞苗期及成株期分别对甘肃省甘南藏族自治州合作市、临潭县和卓尼县等青稞主产区的根腐病发生情况进行调查并采集样品,采用常规的组织分离法分离其病原,结合形态特征和分子生物学进行病原鉴定,并用烧杯水琼脂法和盆栽法测定其致病性。结果表明,青稞镰孢根腐病在甘肃省甘南藏族自治州分布广泛,发病率在5%~20%之间。发病植株长势弱、发黄,茎基部缢缩、腐烂,穗白粒瘪,茎秆发褐或黑红。共分离得到88株青稞镰孢根腐病病原菌,苗期50株,成株期38株,经鉴定分别为燕麦镰孢Fusarium avenaceum、木贼镰孢F. equiseti、三线镰孢F. tricinctum、柔毛镰孢F. flocciferum、锐顶镰孢F. acuminatum及F. langsethiae。盆栽法和烧杯水琼脂法所测得的致病性差异显著,但均表明燕麦镰孢综合致病力较强,结合其分离率,确认燕麦镰孢为优势病原。     

大豆根腐病生态学研究──Ⅱ．不同土壤条件对大豆根腐病的影响

在温室内进行盆栽试验，人为控制土壤理化条件，探讨土壤不同生态条件对大豆根腐病发生的影响。结果表明：土壤干燥和湿度过大均加重根腐病的发生，随着土壤容量增加，根腐病逐渐加重，上壤偏酸有利于大豆根腐病的发生。     

多菌灵与碱式硫酸铜混用防治人参病害的效果

人参黑斑病、锈腐病和菌核病对人参生产影响较大,每年都有不同程度的发生,本文研究了多菌灵与碱式硫酸铜混用对病害发生率的影响.结果表明,单独使用多菌灵的处理,黑斑病、锈腐病和菌核病平均发生率为18.8％,多菌灵与碱式硫酸铜混用病害平均发生率为7.2％,较对照下降了11.6％,达到显著标准;人参产量较对照增加16.7％,达到显著标准.     

橡胶树红根病病原菌rDNA-ITS序列鉴定

为了更好地对橡胶树红根病病原菌进行鉴定,从海南省和云南省发病严重的胶园采集病害样本、分离得到12个灵芝属菌株,并对其rDNA-ITS序列绘制Ganoderma属系统发育树。结果表明,采集得到的12个菌株中有11个鉴定为Ganoderma philippii、1个鉴定为G.gibbosum。     

First documentation on status of barley diseases from the high altitude cold arid Trans-Himalayan Ladakh region of India

Cold arid trans-Himalayan Ladakh region of India bordering with Pakistan and China is one of most elevated inhabited regions of the world. This region is highly vulnerable to climate change and serious environmental threats resulting in reduction in crop productivity due to risk of agricultural pest and plant pathogens. The present work describes the various diseases attacking barley from this region where the status of barley diseases has not yet been explored. Extensive field surveys were conducted for the first time during 2004-2005 and 475 fields were inspected at the 95 locations. Yellow rust, powdery mildew, leaf spot blotch/blight, covered smut, loose smut, foot/root rot and cereal cyst nematode causing molya disease were encountered during the survey. However, yellow rust, molya and foot/root rot were found as the most destructive diseases. Excellent hotspots of the encountered diseases were identified and marked which may be used for the screening of barley genotypes and determining the impact of climate change on plant diseases.     

Nematodes and fungal diseases in barley and wheat on Prince Edward Island

A total of 31 genera and 28 species of plant and soil nematodes were identified from 30 commercial fields each of barley and wheat on Prince Edward Island. Root-lesion nematodes, primarily Pratylenchus penetrans, were the dominant plant parasites, and the only endoparasitic nematodes recovered from roots. Root-lesion nematodes were the dominant genus in soil, but stunt nematodes (Tylenchorhynchus spp., primarily T. dubius, and Merlinius spp.), and pin nematodes (Paratylenchus spp.) were also recovered frequently. Common root rot, barley net blotch, and wheat leaf blotch, incited by Cochliobolus sativus, Pyrenophora teres, and Leptosphaeria nodorum, respectively, were prevalent in barley and wheat. The nematicide aldicarb reduced the numbers of root-lesion nematodes in roots and soil in experimental plots during 1984–1987, except from soil in wheat and barley in 1984 and in barley in 1986. Aldicarb treatments also increased grain yields significantly by 10% and 19% in 1984 and 1987, respectively. Aldicarb treatments did not affect the incidence of common root rot, barley net blotch, or wheat leaf blotch disease. Correlation and regression analyses of data from experimental plots did not indicate any significant relationships between population levels of root-lesion nematodes in roots or soil and severity of root or foliar diseases in barley or wheat.     

Improved waterlogging tolerance of barley (Hordeum vulgare) by pretreatment with ethephon

ABSTRACT

Root growth into hypoxic or anoxic waterlogged soil relies on internal aeration in plants. The plant hormone ethylene helps adapt to waterlogging by inducing the formation of aerenchyma, which provides a low-resistance pathway for the transport of oxygen from the shoot to the root apex. Waterlogging-susceptible crops including barley start to form aerenchyma after suffering waterlogging stress. But waterlogging can be fatal if aerenchyma formation is not fast enough. Here, we investigated whether pre-treating barley with ethephon, an ethylene-releasing agrochemical, could improve its tolerance to mimicked waterlogging conditions (using stagnant deoxygenated agar nutrient solution). In barley growing in aerated nutrient solution, ethephon treatment enhanced aerenchyma formation at the root tips and induced the development of shorter and shallower roots. Pre-treating barley leaves also delayed waterlogging-caused whiting and increased the percentages of viable root-tips under waterlogging conditions. However, the pretreatment did not noticeably increase fresh weight or shoot length. Further studies are needed to optimize ethephon treatment conditions to improve barley production under waterlogged conditions.     

Associations of biophysical factors with faba bean root rot (Fusarium solani) epidemics in the northeastern highlands of Ethiopia

Two field surveys were conducted during the 2010 and 2011 cropping seasons to determine the distribution and importance of faba bean root rot, Fusarium solani (Mart) Apple and Sacc. in the northeastern highlands of Ethiopia. The associations of the root rot incidence and severity with independent variables was analyzed using a logistic regression model. The associations of disease incidence and severity with biophysical factors were evaluated. The disease incidence and severity varied among soil types, crop management practices and cropping seasons. Disease incidence and percentage severity index were higher in 2010 (44.6%) than 2011 (44.4%) due to the high rainfall in 2010. Cropping season, soil type, land preparation and weed management practices were significantly associated with faba bean root rot incidence and percentage severity index in a multiple-variable model. A root rot incidence of ≤50% and severity of ≤40% showed high probability of association with season, furrow sowing and weed management practice, whereas vertisols, flat sowing, high soil moisture and high weed density had significant contributions to root rot epidemics. In contrast, elevation, cropping system and crop density were not associated with the root rot incidence and percentage severity index. Our results showed that root rot is a major biotic constraint in the study area and suggested that proper soil drainage and weed management practices could contribute to reduce the impact of the disease until resistant faba bean genotypes are developed and distributed to small-scale faba bean growers in northeastern Ethiopia and other similar areas of the country.     

油梨根腐病病原菌的鉴定、生物学特性及室内药剂筛选

根腐病是油梨的毁灭性病害之一,该病害为害根部,引起根部变黑腐烂,严重时导致植株死亡。从发病典型的植株根部分离、纯化菌株,并开展致病性测定、形态学特征和多基因位点（ITS、LSU和COXⅡ）系统发育树分析相结合的病原菌鉴定。结果表明,引起海南油梨根腐病的病原菌为樟疫霉（Phytophthora cinnamomi）。还研究了不同培养条件和10种药剂对病原菌菌丝生长的影响。结果表明,病原菌在PDA培养基上生长较好,最适生长温度为28 ℃,最适pH为8,黑暗条件更适合病原菌的生长;烯酰吗啉对病原菌的抑制作用最强,EC₅₀为0.0929 μg/mL。本研究结果为油梨根腐病的田间防控提供了一定的理论依据。