大麦、黑麦和小黑麦种质资源对赤霉病抗性的鉴定

采用单花注射接种法对大麦属、黑麦属和小黑麦共１９个种２１７份材料进行抗赤霉病性鉴定。大麦属一年生野生种高感赤霉病，栽培大麦品种间抗性有较大差异，二棱大麦比六棱大麦抗性强。在大麦多年生野生种中，发现了一些高抗赤霉病的新抗源。大多数黑麦和小黑麦表现中抗赤霉病     

大麦黄花叶病的研究

 大麦黄花叶病的病状是黄色花叶,有时叶片生短坏死条斑,植株矮缩。寄主仅大麦属(Hordeum spp.)8种。小麦属(Triticum spp.)17种,山羊草属(Aeoilops spp.)11种,黑麦(Secale cereal)和燕麦(Arena sativa)等40种禾本科植物不感染。     

栽培大麦×纤毛鹅观草属间杂种后代系抗赤霉病研究

 本文研究了栽培大麦×纤毛鹅观草属间杂种后代60个系群及其亲本在接菌条件下的抗赤霉病表现。从每穗发病百分率、发病动态进程和穗轴病变率等多个侧面对属间杂种后代系的抗性进行了分析。结果表明:1.发病百分率:参试各系未出现高抗(小穗受害率< 3.93%)和高感(小穗受害率> 57.3%)的类型。后代系属R级(抗病)的共7系,占11.7%;属MR级(中抗)的共25系,占41.7%;其余28系属MS级(中感)和S级(感染),占46.7%。当按病情指数来划分时,则R级和MR级所占比例更大。2.变动系数:属抗病级的各系,在接菌后第8 d的第一次调查中,基本上未发病,以后各期的变动系数均小;属感病级的各系,第一次调查时感病就重,以后各期的变动系数也高。3.属抗病的各系,穗轴节的病变最轻,感病各系较重,大麦亲本最重。此外,还讨论了作物对赤霉病抗性的机理、抗性级别划分标准和属间基因转移等问题。     

扬麦四号耐赤霉病性的测定

小麦赤霉病在南京市郊已连续两年(1984,1985)达中度以上流行,种植抗病品种是防治赤霉病最经济有效的措施。目前抗病品种很少,且存在抗性高者产量低,而产量高者抗性就低的矛盾,因而尽快培育抗病品种是十分重要的。 关于抗赤霉病品种的利用,目前主要是抗扩展品种,如苏麦三号,宁8026等;也有极少数抗侵入的品种,如镇74—95,由于农艺性状较差,在生产上应用较少。此外,还有抗接触的避病特性品种,如江苏各地的大     

延边地区稻田抗药性杂草防除技术研究

2002年在延边稻区首次发现抗磺酰脲类除草剂慈姑以来,稻田陆续出现抗磺酰脲类除草剂的雨久花、藨草、牛毛毡和抗二氯喹磷酸的稻稗生态型。其中,抗性藨草和稻稗生态型仍处于蔓延状态。抗药性特征的分析结果,抗性稻稗生态型的抗二氯喹磷酸程度因地而异,高抗生态型的抗性系数(R90/S90)达到60。在标准使用剂量条件下,有效防除抗二氯喹磷酸稻稗生态型的除草剂有氰氟草酯、五氟磺草胺、丙草胺、丁草胺;有效防除抗磺酰脲类除草剂的慈姑、雨久花、藨草、牛毛毡生态型的除草剂有灭草松、2甲4氯、五氟磺草胺、嘧啶肟草醚、吡唑特。     

辽宁花生主栽品种(系)对褐斑病和网斑病抗性鉴定

本研究旨在明确辽宁花生主栽品种(系)对花生褐斑病和网斑病的抗性,以期为抗病育种及田间病害防治提供理论依据。试验采用田间自然病圃法,对辽宁主栽的16个花生品种(系)进行了褐斑病和网斑病田间抗性鉴定。结果表明,供试花生品种(系)对两种叶部病害抗性存在显著差异,但缺乏免疫和高抗品种。对花生褐斑病抗性鉴定结果表明,‘阜花17’属抗病类型,‘鲁花11’、‘铁引花2号’、‘良青8号’、‘新花2号’和‘锦花15’属中抗类型,其余属高感或感病类型。对花生网斑病抗性鉴定结果显示:‘鲁花11’、‘铁引花2号’和‘白花生’属抗病类型,‘黑花生’、‘新花2号’、‘花育20’、‘锦花14’、‘新花1号’、‘锦花15’和‘良青8号’属中抗类型,其余属高感或感病类型。多数花生品种(系)对花生叶斑病综合抗性较差。     

湖北省小麦品种(系)对赤霉病、条锈病、白粉病和纹枯病的抗性评价

为了解湖北省小麦品种(系)的抗病性水平,对2001年以来湖北省审定的46个小麦品种和在湖北省进行区域试验的447份小麦品系进行赤霉病、条锈病、白粉病和纹枯病等4种主要病害的抗病性评价。结果表明:1)参试品系中有1份材料对赤霉病表现高抗,未发现对纹枯病表现高抗或免疫的材料;对赤霉病和纹枯病的平均抗性评价分值分别为14.30和3.49,介于中感和高感之间;对条锈病和白粉病的平均抗性评价分值分别为13.43和8.34,介于中抗和中感之间。2)审定品种的综合抗性水平不高,对条锈病的抗性评价分值为12.47,介于中抗和中感之间,对其他3种病害的抗性介于中感和高感之间;审定品种的单产呈增加趋势,株高在不断降低,生育期相应延长,综合抗病性也在增强。3)审定品种的综合抗病性与对条锈病抗性的相关系数最高,为0.738;对纹枯病的抗性与株高呈显著正相关,与单产呈显著负相关;对赤霉病的抗性与株高无显著相关。鉴于此,湖北省需加强抗病育种力度,同时应充分做好小麦病害的防控。     

栽培大麦×纤毛鹅观草属间杂种后代系抗赤霉病研究

本文研究了栽培大麦×纤毛鹅观草属间杂种后代６０ 个系群及其亲本在接菌条件下的抗赤霉病表现。从每穗发病百分率、发病动态进程和穗轴病变率等多个侧面对属间杂种后代系的抗性进行了分析。结果表明：１发病百分率：参试各系未出现高抗（小穗受害率＜ ３９３％ ）和高感（小穗受害率＞ ５７３％ ）的类型。后代系属Ｒ 级（抗病）的共７ 系,占１１７％ ;属ＭＲ 级（中抗）的共２５ 系,占４１７％ ;其余２８ 系属Ｍ Ｓ级（中感）和Ｓ级（感染）,占４６７％ 。当按病情指数来划分时,则Ｒ 级和ＭＲ 级所占比例更大。２变动系数：属抗病级的各系,在接菌后第８ ｄ 的第一次调查中,基本上未发病,以后各期的变动系数均小;属感病级的各系,第一次调查时感病就重,以后各期的变动系数也高。３属抗病的各系,穗轴节的病变最轻,感病各系较重,大麦亲本最重。此外,还讨论了作物对赤霉病抗性的机理、抗性级别划分标准和属间基因转移等问题。     

大豆种质资源对大豆孢囊线虫的抗性评价

 大豆孢囊线虫(Heterodera glycines Ichinohe,SCN)是大豆(Glycine max (L.) Merrill)生产中的毁灭性害虫,种植抗性品种是控制其危害、减少产量损失的最佳途径。本研究通过温室盆栽实验评价了300份大豆种质对大豆孢囊线虫3号和4号生理小种的抗性。分别筛选到高抗和中抗3号生理小种的大豆种质27份和21份;高抗和中抗4号生理小种的大豆种质11份和9份。在所有供试材料中有10份材料同时对大豆孢囊线虫3号和4号生理小种表现高抗。线虫侵染实验表明,抗性材料对大豆孢囊线虫的发育有阻碍作用,并能显著降低最终形成的孢囊数。     

新疆棉田杂草龙葵对二甲戊灵的抗性水平及多抗性测定

为明确新疆棉田杂草龙葵对二甲戊灵的抗性水平及对其他常用土壤处理型除草剂的多抗性,本研究分别采用培养皿种子检测法和整株植物检测法,测定了采自新疆不同地区的56个龙葵种群对二甲戊灵的抗性,比较了两种检测方法的差异;依据整株植物检测法的结果,分别选取敏感(SHZ-8)、中抗(CJ-2)及高抗(BL-1) 3个种群,测定了其对扑草净、乙氧氟草醚和丙炔氟草胺的多抗性。结果表明：两种方法检测结果的抗性趋势一致,新疆龙葵对二甲戊灵的整体抗性水平为北疆>南疆、东疆,但培养皿种子检测法的抗性指数普遍低于整株植物检测法。培养皿检测法的敏感、低抗、中抗和高抗种群分别占总数的12.5%、71.4%、12.5%和3.6%,整株检测法中该指标分别为5.4%、73.2%、16.0%和5.4%;两种方法检测结果均表明,新疆棉田龙葵对二甲戊灵大多为低到中抗水平。相较于敏感种群SHZ-8,BL-1种群在两种检测方法中相对抗性均最高：培养皿种子检测法的GR₅₀值为90.30 mg/L,抗性指数为20.62;整株植物检测法的GR50值为4 805 g/hm²,抗性指数为26....     

脱氧雪腐镰刀菌烯醇在小麦赤霉病病程中的作用

 脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)系小麦赤霉病菌——禾谷镰孢(Fusarium graminearum,有性态Gibberell azeae)产生的一种单端孢霉烯族毒素(trichothecenes,以下简称"单族毒素")。作者以病菌正常产毒的野生型菌株GZ3639及其产毒基因Tri5损坏、不能产毒的转化子GZT40(Tri5^-,TRI^-)为材料,对DON在病菌致病过程中的作用进行了研究。结果显示:GZ3639能引起典型的赤霉病症状,病害可由接种小花发展至其它小穗,病菌也可定殖于其它小穗组织;而GZT40仅在接种小花处产生鸟眼状坏死斑点,不能引起典型的赤霉病症状,病菌仅定殖于接种小花处。当病菌与一定浓度(400 μ g·mL^-1)的DON混合处理小花后,GZT40的定殖时间提前2 d (感病品种上)至4 d (抗病品种上),定殖范围可扩大到1~3个小穗,接种20 d后的病小穗率也由病菌单独接种时的2.8%提高到12.5%。DON也使GZ3639的定殖时间提前1 d (感病品种上)至2 d (抗病品种上),定殖范围更广,其所致的病害发展更迅速,接种后20 d的病小穗率由病菌单独接种时的78.0%提高到100%。因此,作者认为,单族毒素在病害发展和病菌在寄主组织内的扩展中起着决定性作用,一旦丧失产毒能力,病菌虽能侵入寄主,但不能在寄主组织中扩展。DON可以缩短病菌成功定殖寄主所需的时间,更有助于病菌在寄主组织内的扩展。     

Amplified fragment length polymorphism markers linked to a major quantitative trait locus controlling scab resistance in wheat

ABSTRACT Scab is a destructive disease of wheat. To accelerate development of scab-resistant wheat cultivars, molecular markers linked to scab resistance genes have been identified by using recombinant inbred lines (RILs) derived by single-seed descent from a cross between the resistant wheat cultivar Ning 7840 (resistant to spread of scab within the spike) and the susceptible cultivar Clark. In the greenhouse, F(5), F(6), F(7), and F(10) families were evaluated for resistance to spread of scab within a spike by injecting about 1,000 conidiospores of Fusarium graminearum into a central spikelet. Inoculated plants were kept in moist chambers for 3 days to promote initial infection and then transferred to greenhouse benches. Scab symptoms were evaluated four times (3, 9, 15, and 21 days after inoculation). The frequency distribution of scab severity indicated that resistance to spread of scab within a spike was controlled by a few major genes. DNA was isolated from both parents and F(9) plants of the 133 RILs. A total of 300 combinations of amplified fragment length polymorphism (AFLP) primers were screened for polymorphisms using bulked segregant analysis. Twenty pairs of primers revealed at least one polymorphic band between the two contrasting bulks. The segregation of each of these bands was evaluated in the 133 RILs. Eleven AFLP markers showed significant association with scab resistance, and an individual marker explained up to 53% of the total variation (R(2)). The markers with high R(2) values mapped to a single linkage group. By interval analysis, one major quantitative trait locus for scab resistance explaining up to 60% of the genetic variation for scab resistance was identified. Some of the AFLP markers may be useful in marker-assisted breeding to improve resistance to scab in wheat.     

不同小麦品种抗赤霉病性类型和抗毒素积累能力分析

赤霉病是我国小麦上的重要病害,品种抗病性利用是控制病害发生的重要措施,明确小麦抗赤霉病资源的抗性类型,有利于小麦抗赤霉病育种。2003年和2004年对9个常用抗源在穗期进行单花滴注和喷雾接种,研究其抗侵染和抗扩展性,并对病穗中的脱氧雪腐镰刀菌烯醇(DON)的含量进行分析。结果表明,望水白和苏麦3号具较好的抗侵染和抗扩展能力,其中望水白的抗扩展性最好;感染赤霉病后,DON在5个抗源穗组织中的含量差异显著,DON在望水白和繁60096穗组织中积累量明显比在苏麦3号、延岗坊主和翻山小麦低。通过对望水白/安农8455遗传群体两年的病小穗率和病穗中DON毒素含量的比较,发现二者具有一定的相关性,且受环境影响比较大。     

Evaluation of type I fusarium head blight resistance of wheat using non-deoxynivalenol-producing fungi

A series of experiments was conducted to determine whether type I resistance (resistance to initial infection) to fusarium head blight (FHB) in wheat could be assessed using fungal species/isolates that do not produce deoxynivalenol (DON), a mycotoxin critical to the spread of Fusarium graminearum in the wheat spike. It was shown that, while the non-toxin-producing species Microdochium nivale and M. majus could infect following spray inoculation of wheat spikes, they were unable to spread within the spike following point inoculation. However, although these species might reveal type I resistance, they are not highly pathogenic towards wheat. A nivalenol (NIV)-producing isolate of F. graminearum caused high levels of disease following spray inoculation, but spread only very slowly within the spike and rarely induced bleaching above the point of inoculation. It is proposed that spray inoculation with an appropriate, aggressive, non-DON-producing FHB pathogen may be used to characterize type I resistance to complement point inoculation with a DON-producing isolate to assess type II resistance (resistance to spread within the spike).     

Distribution of Mycelial Colonies and Lesions in Field-Grown Barley Inoculated with Fusarium graminearum

ABSTRACT External surfaces of barley florets have thick-walled epidermal cells resistant to direct penetration by the head blight pathogen, Fusarium graminearum. Surfaces within the floral cavity have thin-walled, susceptible cells. How the fungus gains access to the floral cavity, causing head blight, has not been determined. To investigate pathways of entry, field-grown plants were sprayed with macroconidial inoculum after heads emerged from the flag leaf sheath and then were mist irrigated daily in the morning and evening. On selected days, 1 to 8 days after inoculation (DAI), 80 to 190 florets per day were harvested, dissected, and examined for presence and location of mycelial colonies. At 1 to 12 DAI, 57 to 100 florets likewise were examined for lesions. Patterns of colonization indicated that the fungus entered florets principally through crevices between the overlapping lemma and palea or through the apical floret mouth. The crevices were open for entry until approximately 8 days after heads emerged. Most florets had mycelial colonies on the external surface in a sheltered pocket near the base of the ventral furrow of the palea. Mycelia spread laterally from the furrow to the crevice between lemma and palea. Anther colonization had only a minor role in invasion of florets. Hyphal penetration of stomates was not seen. Lesions usually developed first within 3 mm of the floret apex or 3 mm of the floret base. Within florets, lesions often were contiguous between lemma and palea, palea and caryopsis, or in all three floret parts. However, lesions in the caryopsis developed later and were fewer in number than in the lemma and palea and always were associated with lesions in the palea. The results show the importance of initial mycelial colonization of floret outer surfaces, pathways of entry via lemma or palea crevices or floret mouth, and spread of lesions within the floret at interfaces between lemma, palea, and caryopsis.     

甘薯品种对疮痂病的抗性及其机理分析

为查明我国南方甘薯主栽品种抗疮痂病的能力,用疮痂菌孢子悬液对16份品种作苗期接种与田间病情系统观察.结果表明,广薯79-15、潮薯1号等8份表现感病-中感;福薯26、广薯88-70等8份表现中抗-高抗;不同抗、感品种在田间表现长短不一的感病期.对6份品种藤蔓不同的部位和株龄的组织结构作显微测量与计数、接种试验以及糖含量测定显示,不同品种皮层组织结构差异决定对疮痂病的抗、感性;抗病品种藤蔓具有较厚的角质层,叶片气孔和幼嫩组织的腺鳞数目都较少,表现潜育期长,病斑少.且同一品种不同株龄皮层结构差异与感病程度间有密切关系,但其藤蔓糖含量与品种抗性之间不相关.     

Effect of Trichothecenes Produced by Fusarium graminearum during Fusarium Head Blight Development in Six Cereal Species

Fusarium head blight (FHB) is a complex cereal disease associated with trichothecene production; these mycotoxins are factors of aggressiveness in wheat. Six species (bread and durum wheat, triticale, rye, barley and oats) were submitted to point inoculations with two isogenic strains of Fusarium graminearum; a wild strain (Tri5 +) produced trichothecenes and the mutated strain (Tri5 –) did not. The trichothecene-producing strain was generally more aggressive than the non-producing strain, but this varied according to crop species. The difference in aggressiveness was less pronounced in rye, a very resistant species. High resistance levels were observed in oats due to the large spacing between florets. In six-row barley, despite the existence of a moderate Type II resistance, the fungus was often observed to move externally from one floret to another within the dense spike, without penetrating the rachis. Bread wheat had low resistance to the trichothecene-producing strain and good resistance to the non-producing strain. Triticale responded to the strains in a similar way but was somewhat more resistant to both: symptoms on the spikelets and rachis of the triticales were restricted to below the point of inoculation. Durum wheat was susceptible to the trichothecene-producing strain and only moderately resistant to the non-producing strain, which was able to cause serious damage only to this species. Our study confirmed that the role of trichothecenes in FHB pathogenesis differs among species. The failure of the trichothecene non-producing F. graminearum strain to spread within the inflorescence of wheat, triticale, rye and barley, and the significant reduction of spread in the durum wheat spike strongly suggested that trichothecenes are a major determinant of fungal spread and disease development in Triticeae.     

梨叶叶龄与梨黑星病菌侵染发病的关系

田间试验结果表明，鸭梨叶片在生长发育期抗病性差，易感染黑星病；发育成熟后，抗病性逐渐增强。自然条件下，受叶片抗病性和孢子着落量的综合影响，鸭梨成熟叶片很少感染黑星病。鸭梨叶片从展叶到发育成熟，在梨树生长发育前期（盛花期后60d内）约需40d，后期（盛花期60d后）约需30d。正处在生长发育期的鸭梨叶片受侵染，潜育期为18－25d，发病后，病斑大，产孢期短；成熟叶片受侵染，潜育期多在40d以上，发病后，病斑小，产孢期长。梨树生长前期梨黑星病的流行主要由于大部分叶片正处在生长发育期抗病性较差；后期果实发病则主要源于成熟叶片内长期潜育和长期产孢的黑星病菌。     

广东省甘薯疮痂病病原菌鉴定及国内主要菜用甘薯种质抗性评价

为明确广东省甘薯疮痂病病原菌种类及当前国内主要菜用甘薯种质对疮痂病的抗性,结合形态学特征和rDNA-ITS序列分析对病原菌进行鉴定,并通过病圃诱发结合人工喷雾接种法对来自9个省区30个菜用甘薯种质进行连续2年的抗性鉴定.结果 显示,共获得15株形态学特征及培养性状相似的菌株,其中代表菌株CRI-CJ的形态学特征与甘薯痂...