稻褐飞虱致害性变异的研究

 研究了杭州褐飞虱田间种群在抗虫品种ASD7上强迫饲养多代后致害性的变化。结果表明,不同致害性的群体,在ASD7上饲养4代后,均可转变成能为害ASD7的ASD7种群。反之,在无抗性胁迫的感性品种TN1上连续饲养7代,ASD7种群对ASD7的致害性逐渐减弱,最终退化为TN1种群。这表明褐飞虱的致害性是可变异的,水稻品种抗、感虫特性是其转化的诱因。     

水稻种质资源抗灰飞虱评价及抗性机制分析

通过改进的苗期集团筛选法,对138份水稻种质进行了抗灰飞虱鉴定与评价。筛选出对灰飞虱具有不同程度抗性的材料25份,占总鉴定材料的181%,其中高抗种质2份,抗性种质9份,中抗材料14份,粳稻品种明显比籼稻感虫。对部分材料进行的排驱性、抗生性试验及相关分析表明,Rathu Heenati(RHT)、Mudgo、Kasalath和IR36对灰飞虱具有强的排驱性和抗生性,其抗性水平与这两种抗虫机制密切相关;道人桥、羊毛谷的抗生性强,但排驱性弱,其主要抗虫机制表现为抗生性;Dular、ASD7和密阳23对灰飞虱具有较强的排驱性和抗生性,表明排驱性和抗生性是这3个品种的重要抗性类型;DV85具有较强的排驱性,但抗生性较弱,窄叶青8号和鬼衣谷具有中等水平的抗生性和排驱性,推测这3个材料具有较好的耐害特性。中抗材料9311的抗性水平由中等排驱性和抗生性控制,V20A的抗性主要表现为排驱性,明恢63和扬粳9538的排驱性和抗生性均较弱,暗示其抗性机制主要是耐害性。上述具有强抗生性或排驱性的材料是理想的抗灰飞虱资源。     

水稻品种对稻飞虱抗性鉴定方法的比较研究

采用苗期群体筛选、苗期单株鉴定、分蘖盛期单株鉴定、蜜露量测定和若虫发育历期测定5种方法,分别测定了6个新近育成的、不同类型的水稻优质、高产新品种对褐飞虱和白背飞虱的抗性反应。多数品种在苗期接虫鉴定情况下的抗性表现都是一致或十分接近的,而且与品种的类型和抗感性无关。但少数品种随着苗龄的增大,其抗虫性有不同程度的提高。蜜露斑面积测定结果与分蘖盛期接虫鉴定结果基本吻合,初步将蜜露斑面积与抗性级别的关系拟定为：蜜露斑面积［mm2/(雌虫·d)］ 0～100.0≈ 0～3级,100.1～200.0≈5级,>200.1 ≈ 7～9级。综合多项测定指标,认为分蘖盛期接虫鉴定较苗期鉴定更能准确地反映水稻品种成株期的抗性水平;苗期群体筛选和蜜露量测定是水稻抗飞虱的两个快速、便捷、准确的鉴定方法。     

温度对水稻抗褐飞虱特性的影响

 为研究温度对水稻抗褐飞虱特性的影响,于2007年和2008年应用苗期集团筛选法（SSST）在杭州地区的自然条件下测定了抗性水稻品种IR26和IR36对田间褐飞虱的抗性,同时比较了不同温度（22℃、25℃、28℃、31℃和34℃）下IR26和IR36对褐飞虱的抗性、可溶性糖和草酸含量的变化。自然条件下,IR26已完全失去对杭州种群褐飞虱的抗性,而IR36仍具中等抗性。在25℃到34℃的范围内随着温度升高,IR26对褐飞虱抗性减弱,但22℃条件下抗性比25℃更弱。IR36在温度升高的条件下对褐飞虱的抗性总体呈降低趋势,在31℃和34℃下也已完全失去对褐飞虱的抗性。在22~25℃条件下,IR26和IR36的持抗期均在25℃下最长,分别为9 d和11 d。3个品种稻株中的可溶性糖含量均随温度升高而增加,而草酸含量则随温度升高先增加后下降,在25℃时为最大值。不同温度下及不同水稻品种之间稻株内可溶性糖和草酸的含量均有显著差异。     

褐飞虱IR56种群的致害特征

含Bph3抗褐飞虱基因的水稻品种自20世纪80年代在东南亚推广后,迄今仍对褐飞虱有较好的抗性,受到我国抗褐飞虱育种专家的重视。在IR56水稻(含Bph3基因)上连续40多代胁迫饲养获得褐飞虱IR56寄主种群,从褐飞虱的生长、发育、繁殖以及水稻品种的抗感反应(SSST法测定)两方面对该种群的致害性进行了研究。结果表明:1)在抗性水稻IR56上,褐飞虱IR56种群的羽化率、初羽化成虫体质量、成虫寿命、产卵量、蜜露排泄量、体质量增量等均较褐飞虱TN1种群显著增加,若虫历期则显著缩短;与感虫水稻TN1上的IR56种群或TN1种群相比,除成虫寿命、蜜露排泄量和体质量增量显著下降外,羽化率、产卵量、卵孵化率无显著差异,初羽化成虫体质量、若虫历期尽管差异显著但数值上较接近(其差值不及IR56水稻上IR56种群与TN1种群差值的1/2)。2)水稻品种苗期抗性反应显示IR56水稻对褐飞虱IR56种群的抗性级别为7级,明显弱于对褐飞虱TN1种群的3级,但略强于TN1水稻对褐飞虱IR56种群或TN1种群的9级。显然,与褐飞虱TN1种群相比,褐飞虱IR56种群对抗性水稻IR56有较强的致害能力,与IR56种群或TN1种群对TN1水稻的强致害水平尽管有一定的差距,但多数指标较为接近。含Bph3基因的水稻品种RathuHeenati对IR56种群抗性为1级,推测可能与该水稻品种存在Bph3以外的其他抗虫基因有关。     

小麦品种抗麦红吸浆虫的研究现状与展望

对小麦品种进行麦红吸浆虫抗性鉴定及抗性机制研究是培育抗虫品种、对麦红吸浆虫实行综合治理的基础工作。本文综述了20世纪50年代以来国内外对小麦品种进行麦红吸浆虫抗性鉴定的大田自然感虫鉴定法、虫圃人工接虫鉴定法、室内鉴定法、数学模型鉴定法，以及目前抗性鉴定所应用的等级评价标准和已取得的抗性鉴定结果；详细介绍了小麦品种抗麦红吸浆虫的形态抗虫机制、避虫机制以及生化抗虫机制中营养物质和次生代谢物质与品种抗虫性的关系。大量研究结果表明，小麦品种对麦红吸浆虫的抗性主要表现在抗性品种以其独特的穗形特征及避害性来阻止其产卵或取食，或通过产生有毒的次生物质或营养上的欠缺使其取食后不能正常发育而死亡。本文还对今后的研究趋势进行了展望。     

不同抗感水稻品种对褐飞虱胁迫的高光谱响应特征

【目的】探究不同抗感水稻受褐飞虱胁迫的高光谱反射率曲线变化及敏感光谱差异,研究水稻植株不同部位的高光谱变化。在此基础上,采用机器学习技术建立水稻褐飞虱抗性鉴定模型,为下一步开发智能化褐飞虱抗性鉴定技术提供重要基础资料。【方法】以三个具不同褐飞虱抗感特征的水稻品种(TN1、Mudgo、RHT)为对象,分析其光谱、植被指数差异并建立抗性级别预测的随机森林模型。【结果】研究发现,褐飞虱胁迫天数与光谱反射率显著相关的波段数及差异显著的波段数随着水稻的抗性水平的上升而减少。同时,在680nm左右,三个品种的光谱反射率与褐飞虫胁迫时间的相关性最好。植被指数分析表明,SIPI、SR_605/760和PSND_b与抗性级别的相关系数绝对值要高于680nm的结果。感虫品种TN1差异最早体现,中抗品种Mudgo其次,高抗品种RHT最后。不同部位的差异首先出现在第1叶叶片和第1叶叶鞘,然后依次为第2叶叶片和第2叶叶鞘以及第3叶叶片和第3叶叶鞘。预测模型的结果表明,全波段作为输入的模型效果比以单一植被指数SIPI构建的随机森林模型更好,模型准确率达到85.9%。【结论】...     

防治褐飞虱的高毒农药替代药剂的室内筛选及交互抗性研究

为了筛选防治褐飞虱的高毒农药的替代药剂,于2005-2006年, 采用稻茎浸渍法测定了6类20余种杀虫剂对广西南宁、桂林,湖南常德和江苏南京褐飞虱种群的室内毒力。结果表明,噻嗪酮、氟虫腈、噻虫嗪、烯啶虫胺、毒死蜱、异丙威、猛杀威、丁硫克百威等8种药剂对褐飞虱具有较高的毒力,可作为替代高毒药剂的候选品种。采用稻茎浸渍法对1个室内褐飞虱种群用吡虫啉筛选23代后,褐飞虱对吡虫啉的抗性从筛选前的200.1倍上升至筛选后的1298.5倍（上升了5.5倍）;高抗吡虫啉的褐飞虱种群对氯噻啉、噻虫啉和啶虫脒表现出明显的交互抗性,而对呋虫胺、噻虫嗪和烯啶虫胺则无明显的交互抗性。 还讨论了褐飞虱的抗性治理策略。     

籼型杂交水稻抗褐飞虱育种研究

 对80份籼型杂交水稻恢复系的抗褐飞虱特性鉴定表明,30份材料对褐飞虱抗性达中抗以上水平,其中12份材料的持抗性优于ASD7。将这12份材料的抗级为0～3级、持抗期≥7 d的优质抗性材料归为一级抗性材料。经杂种优势的测定、外观米质评价、白叶枯病和稻瘟病抗性鉴定,筛选出对两病一虫达中抗水平,与协青早A的杂种产量比对照汕优10号增产12.9%的杂交水稻新恢复系埃红/台1059;以及高抗褐飞虱、高抗稻瘟病、中抗白叶枯病且外观米质极好的恢复系LS2/密阳46。     

小粒野生稻对褐稻虱抗性机制的研究

 通过应用改良苗期群体筛选法，对小粒野生稻进行了抗性鉴定，并根据褐稻虱在抗性品种上的生存率、发育进度、蜜露分泌量、群体建立、虫体重量变化、卵巢发育程度、产卵量和稻株的受害级别等指标与感虫对照品种TN1上的差异显著性作比较，综合评定了小粒野生稻对褐稻虱的抗性机制。试验结果表明，小粒野生稻对褐稻虱的抗性级别为0级，属高抗褐稻虱。在小粒野生稻上，褐稻虱的生存率为18％，蜜露分泌量为6.04 mm2，群体建立为21.8头/对，体重增量为-0.33 mg，卵巢发育为2.9级，产卵量为29.67粒/雌;而在感虫对照品种TN1上，褐稻虱的生存率为82％，蜜露分泌量为46.8 mm2，群体建立为217.0头/对，体重增量为2.27 mg，卵巢发育为4.8级，产卵量为229.3粒/雌。由此可知，小粒野生稻对褐稻虱的抗性机制为抗生性和非选择性。     

Physiological Macro-lesions Enhanced Resistance to Blast （Magnaporthe grisea） in Rice Near-isogenic Lines

Roll-leaf-1 （rl-1） and spot-leaf-1 （spl-1） were two near-isogenic lines, which were obtained after 3 to 4 backcrosses with early season indica rice Zhefu 802 as recurrent parent. Henna macro-lesions, referred as physiological or morphological markers, began to appear on leaves at 4.5- to 6.0-leaf stage. The rice seedlings were inoculated at 3.5-, 5.0- and 7.0-leaf stages with high pathogenic races Zhong A1 and Zhong B1 of Magnaporthe grisea, respectively. The resistance of rl-1, spl-1 and Zhefu 802 against blast was significantly different. The seedlings of Zhefu 802 at 3.5- to 7.0-leaf stage were susceptible to races Zhong A1 and Zhong B1 of M. grisea, whereas those of rl-1 and spl-1 at 3.5-, 5.0- and 7.0-leaf stages were susceptible, moderately resistant and resistant, respectively. These results suggested that the enhanced resistance of rl-1 and spl-1 related to the appearance of their morphological marker lesions. The experiment provided a basis for studying lesion mimic and hypersensitive response in association with disease resistance.     

The Effect of the Amount of Nitrogen Fertilizer on Starch Metabolism in Leaf Sheath of Japonica and Indica Rice Varieties during the Heading Period

Abstract

The effects of the amount of nitrogen fertilizer on the starch metabolism of rice leaf sheath during the heading period in the japonica rice variety, cv. Nipponbare were compared with those in the indica varieties, cv. Tetep and Johna. The rice plants were grown under a low- (similar to the standard nitrogen level in paddy field) or high-nitrogen condition, and the starch content of the second leaf sheaths below the flag leaf was analyzed from the second leaf stage (growth stage 1) until 21 days after the heading (growth stage 7). The starch content of the plants grown under the high-nitrogen condition at the heading stage (growth stage 4) was lower than that under a low-nitrogen condition in all the varieties. The decrease in the activity of starch branching enzyme (SBE) was considered to be important for the repression of starch accumulation under a high-nitrogen condition. Under the high-nitrogen condition, Nipponbare accumulated more starch in the second leaf sheath than indica varieties at the heading stage. However, the phenomenon could not be accounted for by the activities of AGPase and SBE. Semi-quantitative RT-PCR analysis suggested that the lower activities of SBE in the second leaf sheath under the high-nitrogen condition may be due to, at least in part, the decrease in the expression level of RBE4.     

Resistance to late blight in foliage (Phytophthora infestans) of potatoes assessed as true seedlings and as adult plants in the glasshouse

Summary True seedlings from crosses designed to produce progenies having high levels of field resistance to late blight (Phytophthora infestans (Mont.) de Bary) were scored in lots of 25 in a glasshouse. The results agreed with assessments subsequently obtained from plants grown from tubers from the same progenies when screened as individual whole plants in the glasshouse. The resistance of seedlings of both resistant and susceptible progenies was assessed by inoculating them 3–8 weeks after sowing. All were highly susceptible when inoculated at 3 weeks but resistance increased from 3 to 6 weeks and differed little between 6 and 8 weeks. The seedling test appears to provide a valid screen for resistance at an early stage in a breeding programme.     

不同抗性大豆品种感染大豆花叶病毒后一些生理生化性状的变化

本文采用聚丙烯酰胺直板凝胶电泳等方法测定不同抗性大豆品种接种SMVI—1毒株后叶绿素含量及过氧化物酶同工酶谱及酶活性。结果表明,感病品种和中感品种比健林分别多2条和1条酶带。感病品种的过氧化物酶活性最强,是对照的14.5倍,其次是中感品种和抗病品种。感病品种叶绿素含量明显下降,仅为对照的18.57％,抗病品种为74.43％。     

油菜抗病毒病与过氧化物酶关系

用于叶期苗在不接种病毒条件下测试过氧化物酶同工酶结果,在相对迁移率17％—47％内,有6个位点出现酶带,抗、感病品种的酶带数量、酶带出现的位点和强弱程度有明显差别。高抗品种酶带数最多,有E_3和E_4强带,E_3为弱带;高感品种酶带数最少,缺E_6和E_4,E_3为强带;低抗和低感品种的酶带介于高抗与高感品种之间。用酶带数量和各酶带强弱程度,或用酶谱薄层扫描积分值计算距离系数,而后聚类,聚类结果与抗、感病性分组完全一致。证明抗病性与过氧化物酶同工酶有密切关系,用不接种苗酶谱测定可以代替接种鉴定和田间鉴定。     

北方产区花生品种黑斑病抗性鉴定

为筛选花生黑斑病抗源材料，以50个花生品种为材料，在山东省莱西市田间开展黑斑病抗性调查，并在温室条件下对其中7份材料进一步开展抗性鉴定。结果表明，不同花生品种在田间对黑斑病抗性存在差异，共获得4份中等抗病材料；在温室接种条件下，3份材料鉴定为中等抗病。综合田间自然发病和温室人工接种鉴定结果，获得冀农G94、豫花47号和晋花10号3份中抗黑斑病的材料。     

Effect of host plant resistance and insecticide on brown planthopper Nilaparvata lugens (Stål) and predator population development in the Mekong Delta, Vietnam

Crop yield and populations of brown planthopper Nilaparvata lugens (Stål), whitebacked planthopper Sogatella furcifera (Horvath) (Homoptera: Delphacidae), green leafhopper Nephotettix spp. (Homoptera: Cicadellidae), and hemipteran and spider predators were monitored on rice varieties susceptible, moderately resistant, and highly resistant to N. lugens, under insecticide-treated and insecticide-free conditions. Nilaparvata lugens outbreaks and hopperburned plants were observed only in plots of the insecticide-treated susceptible varieties. In insecticide-free plots, the yield of the susceptible variety was lower than those of resistant varieties in only one of four seasons. In plots of a moderately resistant and a highly resistant variety, populations of N. lugens, S. furcifera, Nephotettix spp., and predators were generally similar, and yields did not differ, under both insecticide-treated and insecticide-free conditions. In insecticide-free plots, predator-N. lugens ratios were generally higher on resistant varieties than susceptible varieties. Two conclusions can'be drawn from our results relevant to the question of what levels of N. lugens host plant resistance are appropriate for farmers who do not overuse insecticides. First, susceptible varieties will not necessarily be damaged by N. lugens, even when N. lugens outbreaks occur in adjacent plots. Second, moderate and high levels of N. lugens resistance do not appear to be incompatible with biological control of N. lugens or other homopteran pests.     

Additive genes in wheat for resistance to stripe (yellow) rust (Puccinia striiformis Westend.)

Forty-nine lines of wheat (F₆ generation) containing minor additive genes conditioning resistance to stripe (yellow) rust (Puccinia striiformis Westend.) were evaluated to several virulence types (physiologic races) of the pathogen obtained from the USA and Europe. All wheat lines showed some level of resistance to all virulence types of P. striiformis but there were differences in level of resistance between crosses and between lines within a particular cross. Generally, all lines expressed the most resistance at the seedling stage when grown at higher temperatures (15°C during the dark period; 25°C during the light period) than at 2°C (dark period) and 20°C (light period). Lines with more resistance genes showed the most resistance, and this resistance was least sensitive to temperature change. Mature plants in the field had levels of resistance equal to, or greater than, those of their seedling counterparts. One parent of each cross evaluated was either a commercial cultivar or an advanced wheat selection, and was rated as susceptible. In many cases, these susceptible parents contributed to resistance in the progeny and thus the progeny showed transgressive segregation for resistance. Some parent cultivars, which were completely susceptible as seedlings and moderately resistant as mature plants, also contributed to seedling resistance in the progeny when combined with parents known to contain minor additive genes for resistance to P. striiformis. The advantages of using minor additive genes are discussed in relation to the control of stripe rust of wheat and to crop protection generally.     

河南省308份小麦新品系的茎基腐病抗性评价

为给河南省抗茎基腐病品种合理布局提供品种支撑,以河南省小麦茎基腐病的高致病力假禾谷镰孢菌菌株PY20-20为接种物,对参加河南省主要区域试验的308个小麦新品系进行苗期抗病鉴定。结果发现,供试品系中,95.7%的品系表现为高感(病情指数大于30.00),仅1.95%的品系表现为中抗(病情指数在10.01～20.00之间),3.25%的品系表现为中感(病情指数在20.01～30.00之间),无免疫和高抗品种,表明参加河南省小麦区域试验的新品系对小麦茎基腐病的整体抗性水平较低。为获得茎基腐病抗性稳定的品系,对苗期表现为中抗和中感的品系进行了2次重复验证,发现6个中抗品系(西农1125、郑麦9134、中研麦906、阜麦1008、泰禾麦6号和民研186)和4个中感品系(徐麦14017、周麦36、新麦9389和囤麦257)的抗性水平较为稳定。进一步对6个中抗品系进行成株期抗性鉴定,发现这些品系的病情指数在12.67～15.50之间,成株期对小麦茎基腐病的抗性也达到了中抗水平。综上,西农1125、郑麦9134、中研麦906、阜麦1008、泰禾麦6号和民研186这6个中抗茎基腐病的品系可以在小麦生产...     

亚麻品种资源对枯萎病的抗性评价 —06

利用亚麻枯萎病病圃,对508份国内外亚麻品种资源进行了抗枯萎病的鉴定和评价,按照参试品种较统 一感病对照发病率的降低率,把抗枯萎病程度划分为高抗(HR) 、中抗(MR) 、低抗(LR) 、低感(LS) 、中感(MS)和高 感(HS)共6个级别。各个级别的品种资源数分别为45、38、64、92、112 和157;分别占试验资源总数的8. 9%、 7. 5%、12. 5%、18. 1%、22. 1%和30. 9%。高、中抗资源共计16. 4%。筛选出的高抗和中抗枯萎病资源中有41份 属于首次报道,其中包括13份国外引进品种、7份国内地方品种和21份国内育成品种,一些重点抗源已成功地应 用于亚麻抗枯萎病育种实践。