棉花黄萎病菌安阳菌系致病类型变异研究

以国内外有代表性的菌系为对照,３ 个不同棉种的４ 个品种为鉴别寄主研究了棉花黄萎病菌安阳菌系致病类型的变异。结果表明,安阳菌系的致病力类型有明显变异,其ＡＶＳ菌株的致病力明显强于强致病力类型的陕西泾阳菌系和我国江苏落叶型菌系ＶＤ－ ８,且略高于美国强致病力落叶型菌系Ｔ－ ９,属强致病力类型;病原菌室内培养性状也有变异,ＡＶＳ菌株是近年出现的新类型,其在病株中分离比例呈上升趋势,ＡＶＨ菌株在病株中的分离比例则呈下降趋势;黄萎病的田间症状有不同类型,早期落叶型为近年出现的新类型,具有发病早、重、快、损失重等特点;早期落叶型棉花黄萎病的致病菌与ＡＶＳ菌株关系密切。     

河北省棉区黄萎病菌系基于RAPD的遗传分化研究

本研究对２３个棉花黄萎病菌系,其中１９个为河北省棉区不同致病群（ＶＧｓ）的代表性菌系,用２５个可揭示菌系遗传多态性的随机引物进行ＲＡＰＤ扩增,研究了病菌的遗传分化及与其来源和致病性的关系。结果表明,菌系间的遗传相似系数变化在０．４４２～１．０００之间,但大多数菌系间的同源程度较高。基于８９个ＲＡＰＤ标记的聚类分析表明,供试菌系被划分为２个ＲＡＰＤ群（ＲＧｓ）和８个ＲＡＰＤ亚群（ＲＳＧｓ）,其中河北省棉区黄萎病菌系的遗传分化程度较小,９５％的菌系归属于同一ＲＡＰＤ群（ＲＧ１）,仅１个菌系属于ＲＧ２。ＲＡＰＤ类群与病菌地理来源有一定相关性,但与病菌致病群（ＶＧｓ）相关性不大。进一步分析表明,ＲＡＰＤ亚群（ＲＳＧｓ）与ＶＧｓ间存在一定关系,其中ＲＳＧ１中的８个菌系全部为强致病力的ＶＧⅠ菌系;ＲＳＧ２中６６．７％的菌系为ＶＧⅡ菌系。ＲＧｓ和ＲＳＧｓ与菌系是否与落叶型无关。     

北方植棉区棉花黄萎病菌生理分化类型研究

通过对采自北方植棉区落叶和非落叶病株的５１个棉花黄萎病菌系致病力分化测定结果，确定我国北方植棉区存在落叶类强致病力菌系；混合类中度致病力菌系及非落叶类弱致病力菌系的３个致病类型，并分别占测试菌的４１．５１％、３５．８５％和２２．６４％，其中９个强致病菌系致害棉苗出现落叶程度与对照菌的落叶程度相当或略重，表明河北、山东、河南植棉区重病田有落叶型黄萎菌系。病菌培养性状研究，得出３个培养型，即黑色菌落型、灰白色菌落型与白色菌落型。明确了黄萎病菌生长最佳温度为２５℃，这一结果同田间黄萎病大发生要求的温度一致。     

我国棉花大丽轮枝菌(Verticillium dahliae)电泳图谱分析

对24株来自不同地区、作物的不同致病类型的大丽轮枝菌,进行了同工酶和可溶性蛋白电泳图谱分析。结果表明,24株大丽轮枝菌苹果酸脱氢酶酶谱具有种的特异性,酯酶酶谱具有属的特异性。谷氨酸脱氢酶、过氧化物酶、超氧化物歧化酶和可溶性蛋白电泳图谱与病菌的致病类型有关,可将24株大丽轮枝菌分为2群,群Ⅰ包括20个菌株,均属于中等致病力或弱致病力的非落叶型菌系;群Ⅱ包括4株菌,均属于强致病力的落叶型菌系。     

河北省棉花黄萎病菌致病性与ISSR遗传分化

 从河北省17个主要植棉县采集棉花黄萎病株,分离获得52个黄萎病菌单孢菌系,对其培养特性、致病性和ISSR(Inter-simple sequence repeat)遗传分化进行了研究。菌系培养性状研究表明,在采集的52个菌系中,菌核型菌系最多,其次是菌丝型,最少的是中间型,3种类型菌系分别占总菌系的51.9%,38.5%和9.6%。利用7个抗、感不同的鉴别寄主在光、温、湿可控的生长室鉴定了病菌的致病性,供试菌系可分为致病力强、中、弱3种类型(Ⅰ型、Ⅱ型和Ⅲ型),分别占供试菌系的51.9%,21.2%和26.9%。在供试菌系中存在比落叶型菌系致病力还要强的非落叶型菌系。基于病情指数的聚类分析结果表明,河北省棉花黄萎病菌系存在明显致病力分化,但与地理来源无关。菌核型菌系和中间型菌系多表现为强致病力或中等致病力,而菌丝型菌系的致病力变化较大。在136个ISSR标记中,80个属于多态性标记,多态性位点百分率达58.8%。基于ISSR的聚类分析结果表明,河北省棉花黄萎病菌的遗传分化较小,并且遗传分化与地理来源相关。     

棉花黄萎病菌致病力变异生理机制的初步研究

在4种不同的温度下对31个致病力不同的菌株及落叶型菌株V991进行PDA平面培养,81.3%的强致病力类型菌株表现为菌丝型,落叶型菌株均为菌丝型,80.00%的中等致病力类型的菌株为中间型,弱致病力类型菌株均为菌核型。20～25℃有利于病原菌产生菌核,30℃的较高温度明显抑制菌核的形成。各菌株在25℃条件下菌落生长最快,分生孢子产量和毒素产量最高;30℃的较高温度下,强致病力类型菌株的菌落直径、分生孢子产量和毒素产量均显著大于中等致病力和弱致病力类型,且落叶型菌株高于非落叶型菌株。     

新疆南部棉区黄萎病菌种群致病性分化及变异

 采用鉴别寄主法和特异性引物PCR检测技术对采自新疆南部（南疆）棉区的36个棉花黄萎病菌菌系进行检测,以期明确其病原种群致病性分化及变异情况。鉴别寄主法测定结果显示：供试菌系中致病性强、中、弱的菌系分别为27个、4个和5个,各占75.0%,11.1%和13.9%。特异性引物（ND1/ND2和D1/D2）PCR检测结果显示,供试36个菌系中落叶型菌系12个,占33.3%;非落叶型菌系24个,占66.7%。经统计,落叶型菌系的致病力明显高于非落叶型菌系,其平均病指分别为43.8和31.8。接种试验证明,无论落叶型菌系和非落叶型菌系,接种后都可产生落叶症状,但落叶的情况有明显差别,落叶症状的轻重不仅与菌系的致病类型有关,还与棉花品种的抗病性密切相关。     

棉花黄萎病菌落叶型菌系研究

通过对我国棉花黄萎病菌 V_B 与已知的美国落叶型黄萎病菌 T_9以及我国非落叶型黄萎病菌 V_6、V_10进行对照比较研究,所得结果表明,菌系 V_B 为强致病力,病株落叶成光杆,在6个抗感不同的棉花寄主上致病,平均病情指数达54.6;对不同温度反应显示偏耐高温,适宜生长温度为20～30℃,最佳温度25℃;在 PDA 培养基上菌落白色,微菌核不明显,呈束状膨胀菌丝团等生理特性方面,均和美国落叶型黄萎菌 T_9表现趋于一致,而与非落叶型黄萎菌系差异明显。从而证实江苏常熟徐市的棉花黄萎菌系 V_B 是落叶型的病原菌。为综合防治提供科学依据。     

山西棉花黄萎病菌致病性研究

2001年8月在山西省主产棉区运城、临汾、晋东南、晋中有代表性地取样、分离、纯化、鉴定,取得了19个黄萎病菌代表菌系和3个对照菌系。2002-2003年观察鉴定,山西省的19个代表菌系均属大丽轮枝菌(VerticilliumdahliaeKleb.)。这些菌系在PDA平皿上菌落的增长量、微菌核形成的快慢、数量、形状和大小变化以及黑色素产生的比值等均有差异,其致病力也不同。经温室致病力测定将其划分为3个不同的生理类型,即致病力强的落叶型Ⅰ型、致病力中等的Ⅱ型、致病力弱的Ⅲ型,分别占50.0%、36.4%、13.6%。由于致病力的差异,棉花黄萎病田间的症状表现也不同。     

新疆北部棉花黄萎病菌培养特性、致病型、致病性分化及ISSR遗传变异研究

【目的】明确当前新疆北部棉区黄萎病菌菌系变异和致病力分析情况。【方法】从新疆北部植棉区获得17个棉花黄萎病菌单孢菌系,对其培养特性、致病型、致病力以及ISSR遗传变异进行了研究。【结果】供试17个菌株全部为菌核型,其中落叶型菌系(Defoliating type,D型)有13个,占76.5%;非落叶型菌系(Non-defoliating type,ND型)有4个,占23.5%;D型平均病指(58.72)略高于ND型平均病指(52.7)。在泗棉3号上D型平均病指高于ND型,而在奥3503上D型平均致病力低于ND型。供试菌株按强、中、弱三个致病力类型划分,分别占94.12%、5.88%和0%。ISSR遗传分化与致病型具有一定的相关性,大部分的D型和ND型处于各自不同分支。研究结果还发现,同一地块分离的菌株xj13-3(1)、xj13-3(2)和xj13-3(3)虽同为D型,但ISSR标记可将3个菌株分到不同的亚群上。【结论】试验结果表明了新疆北部棉花黄萎病菌遗传变异关系的复杂性。     

Pathogenic and molecularVariability of Colletotrichum falcatum Went. Isolates from sugarcane with red rot disease symptoms

Pathogenic variability of different isolates of Colletotrichum falcatum Went. collected from six varieties: Co 419, CoC 671 (from Andhra Pradesh), Co 86032, Co87044, 89V74, and a local variety in Bhadrak (from Orissa) were established. Six red rot isolates were differentiated into four distinct pathotypes, viz., pathotype A - Cf 419 and Cf Bdkh; pathotype B - Cf 671; pathotype C - Cf 89V74 and pathotype D - Cf 86032, and Cf 87044. Pathotype A showed a susceptible reaction to Khakai, CoC 671, CoJ 64, and Co 419. Also pathotype B showed a susceptible reaction to Baragua, CoC 671, Co 997, CoJ 64, Co 1148, and Co 975, whereas pathotype C showed a susceptible reaction to CoC 671, Co 7717, Co 997, CoJ 64, Co 975, and Co 419. But pathotype D showed a susceptible reaction to CoC 671 and Co 997. Polymerase chain reaction (PCR) amplification and subsequent restricted fragment length polymorphism (RFLP) analysis of internal transcribed spacer region of ribosomal DNA (rDNA) of Cf 89V74, Cf 671 and Cf Vittal (C. falcatum isolate from Vittal, Karnatak) by four restriction enzymes, Alu I, Msp I, Rsa I, and Pvu II revealed two distinct groups viz.Group 1- Cf 89V74 and Cf Vittal; Group 2-Cf 671. Restriction enzymes Alu I, Msp I, Rsa 1, and Pvu II produced fragment lengths of 380, 520, 550, and 580 bp for Cf Vittal and Cf 89V74, whereas fragment lengths of 420, 370, 440, and 460 bp were observed in Cf 671, respectively. The present investigation with the red rot infected sugarcane samples clearly indicated the existence of two pathotypes viz., pathotype A and pathotype B in Andhra Pradesh and three pathotypes viz., pathotype A, pathotype C, and pathotype D in Orissa. Pathotype C (Cf 89V74) showed similar ITS-RFLP pattern in Cf Vittal which was isolated from Karnataka.     

福建省玉米小斑病菌侵染不同细胞质玉米品种的病斑型及其致病型群体结构分析

[目的]为了解福建省玉米小斑病菌的致病性及其群体结构,[方法]研究了2014-2015年采自福建省7个地区的247个菌株侵染不同细胞质玉米品种C103T、C103C、C103S和C103后叶片的病斑型,[结果]结果表明,所有供试菌株均可引起4个玉米品种发病,其病斑长度平均值分别介于1.15 mm-5.40 mm、1.06 mm-4.70 mm、1.09 mm-4.84 mm和1.15 mm-5.21 mm之间。根据病斑长度将病斑分为I和II型,其菌株出现频率分别为80.26%和19.74%。依据各菌株依次在4个不同品种玉米上的病斑型,供试菌株群体被划分出15个致病型,其中致病型CHP15(病斑反应型I-I-I-I)为优势型,致病型CHP11(病斑反应型II-I-I-I)为亚优势型,优势型和亚优势型分别占供试总菌株数的57.49%和9.72%。[结论]不同地区菌株之间的致病型组成及其出现频率存在多样性。此外,其中的235个O小种菌株也出现了14个致病型,菌株间的致病力存在明显的分化。     

Detection and inheritance of leaf rust resistance in common wheat lines Agra Local and IWP94

Genetic studies were undertaken to determine the number and identities of leaf rust resistance genes in common wheat lines Agra Local and IWP94. The infection type arrays of the two lines with eight pathotypes (pt.) of P. triticina were different from those of lines possessing known leaf rust resistance (Lr) genes. Agra Local possessed two recessive resistance genes, one conditioning resistance to pathotype 4R9-7, and the other, a temperature-sensitive factor, gave resistance to pt. 121R127 at high temperature (27°C). IWP94 was previously demonstrated to carry Lr23. From the present study IWP94 was determined to have at least four leaf rust resistance genes. The first of these was the same recessive gene conferring resistance to pathotype 4R9-7 which was found in Agra Local. A second partially dominant gene conferred resistance to pathotype 121R127 at high temperature and two additional recessive genes governed resistance to pathotype 93R15. When present together, these two recessive genes complemented each other and provided resistance to pathotype 69R13 as well. One of the two recessive genes conferring resistance to pathotypes 93R15 and 69R13 was Lr23.     

Identification and validation of a quantitative trait locus associated with wheat yellow mosaic virus pathotype I resistance in a Japanese wheat variety

Yellow mosaic disease, caused by wheat yellow mosaic virus (WYMV), is one of the most serious diseases of winter wheat (Triticum aestivum L.) in Japan. The three pathotypes of WYMV are distributed in different geographical areas: pathotype I is found mainly in western and central Japan (Kanto), pathotype II in northern Japan (Tohoku and Hokkaido) and pathotype III on the southern island of Japan (Kyushu). A total of 246 doubled‐haploid (DH) lines, derived from a cross between ‘Yumechikara’ (resistant) and ‘Kitahonami’ (susceptible), were evaluated for 2 years for their resistance to WYMV pathotype I. A single major quantitative trait locus, Q.Ymym, mapping to chromosome 2D was associated with resistance to pathotype I in ‘Yumechikara’. This is the first time a QTL responsible for pathotype I resistance has been identified. Fine mapping of Q.Ymym indicated that it was on a tight linkage block originating from ‘Yumechikara’, and the markers associated with this block will accelerate the development of varieties resistant to WYMV pathotype I.     

不同产地香菇氨基酸组成及营养价值评价

为比较不同产地香菇的氨基酸组成差异,使用氨基酸自动分析仪快速检测了5种不同产地香菇的氨基酸组成,采用氨基酸比值系数法对其氨基酸进行营养价值评价。结果表明,不同产地香菇的氨基酸含量不同,总氨基酸含量在(14.39～18.71) g/100 g;必需氨基酸含量相差较大,其范围为(4.68～6.33) g/100 g,必需氨基酸占总氨基酸(EAA/TAA)的平均值为34%,必需氨基酸占非必需氨基酸(EAA/NEAA)的平均值为51%。在5种香菇样品中,亮氨酸的比值系数(RC)最小,为第一限制性氨基酸,氨基酸比值系数分(SRC)平均值为87.846。四川通江(Q5)香菇的SRC值最高,且各必需氨基酸的RC值与1接近,与模式氨基酸最接近,因此从氨基酸含量及必需氨基酸所占比例来讲,四川通江(Q5)香菇的品质最佳,可作为香菇蛋白产品开发与利用的理想资源。     

稻瘟病菌株的DNA指纹及其与小种致病性相互关系的研究

稻瘟病菌生理小种的鉴别对培育抗稻瘟病水稻品种具有重要意义。传统方法利用一套鉴别品种区分小种既复杂又易受各种因素的影响。我们在日本稳定菌株北1的基因组文库中筛选出了一套含重复顺序的克隆，2 个克隆被证实具有高度的多态性。用其中的POR6对17个稻瘟病菌株Southern分析，获得了可分辨和重复的基因组特异的指纹图谱。     

新疆不同产地红枣氨基酸的分析研究

为评估新疆不同产地红枣氨基酸组成差异,以新疆不同产地的红枣为试样,在完成试样17种氨基酸含量研究分析的基础上,依据所得数据,通过主成分分析,对不同产地红枣的氨基酸品质进行了综合评价;同时从模式谱、药效及风味氨基酸的角度,探讨了不同产区红枣的氨基酸特点。结果表明:受试样品中,墨玉骏枣、二二四团骏枣、哈密大枣的氨基酸综合得分分别为1.128、1.020、0.600,高于其他样品;二二四团骏枣必需氨基酸含量占蛋白质总量的比例最高,达68.36%;洛浦骏枣药用氨基酸含量占总氨基酸比例最高,达53.72%;托克逊灰枣、阿克苏灰枣甜味、酸鲜味氨基酸总和与苦味氨基酸的比例较高,达6倍以上。不同产区红枣氨基酸综合得分、模式谱、药效、风味均存在差异,可从氨基酸角度探讨新疆不同产区红枣的营养品质特点。     

Novel pathotypes of lettuce mosaic virus — breakdown of a durable resistance?

Summary Resistance to lettuce mosaic virus (LMV) is derived either from cv. Gallega (g gene) or the wild accession PI251245 (mo gene). Previous studies indicated that these two genes were identical. Breeders in Europe produced numerous resistant cultivars utilisingg while in the USAmo was used. The resistance has been effective for over 20 years. However, recently there have been reports of LMV isolates causing unusually severe and sometimes necrotic symptoms on cultivars with these resistance genes. Investigations of these severe isolates have distinguished three new pathotypes in addition to the common pathotype (II) and identified a novel dominant gene for resistance. Themo/g genes confer resistance to pathotypes I and II but pathotype III possesses virulence for cultivars withg but not for those withmo. These two genes are therefore not identical but are probably either closely linked genes or alleles. Pathotype IV possesses virulence for all lettuce lines so far tested. Some isolates of this pathotype are seed transmitted in cultivars possessingmo org and have caused severe crop losses in southern France. The durability of the resistance conditioned by these two genes is discussed.     

Contribution of incident solar radiation on leaves and pods to soybean seed weight and composition

The weight and composition of soybean seeds (Glycine Max L. Merrill) depend on changes in carbon and nitrogen assimilate supply during grain filling. Soybean pods and seeds are green, evidencing their capacity to capture light. However, the current physiological knowledge does not consider any effect of incident solar radiation reaching the pods on seed weight and composition. The objective of this work was to investigate the response of seed weight and composition to changes in assimilate supply from leaves, to the incident solar radiation reaching the pods and to the combination of both, changes in assimilate supply from the leaves and incident solar radiation on pods of soybean plants. Field experiments were performed during two growing seasons at Balcarce, Argentina. Treatments modified the amount of assimilates supplied by the leaves (plant shading, defoliation), the solar radiation reaching the pods (pod shading) or both (defoliation and pod shading) during seed filling. Plant shading and defoliation reduced seed weight, oil concentration and oil and protein content and increased the concentration of saturated and poli-unsaturated fatty acids while reduced oleic acid percentage. Pod shading increased the concentration of stearic acid and reduced the concentration of linolenic acid. When pods were shaded on defoliated plants, seed weight and oil and protein content decreased while fatty acid composition was similar to values obtained under defoliation treatment. Based on these results, a conceptual model that considers photoheterotrophic nature of reproductive structures of soybean is proposed. Seed weight, oil and protein content and oil fatty acid composition depended on assimilate availability for the seeds. The response of oil and protein content to assimilate supply depended on whether leaves were present or not. The effect of solar radiation incident on pods depended on the amount of assimilates available for the seeds: (i) when carbon allocated was low (defoliation treatments), pods contributed to seed carbon economy but solar radiation incident on them did not affect fatty acid composition; (ii) when carbon allocated to the seeds was high (intact plants), contribution of pods to seed carbon economy was not significant, but the amount of solar radiation incident on pods produced significant changes in fatty acid composition.     

基于多效唑和微喷灌量的麦茬复播谷子品质及矮化效应研究

为有效提升麦茬复播谷子品质及防倒技术，2017—2019年在山西临汾采用裂区、随机区组方法分别开展了多效唑(PP₃₃₃)不同叶龄期的不同喷施浓度、不同生育期微喷灌量对麦茬复播谷子品质及矮化的影响研究。结果表明，不同叶龄期喷施不同浓度PP₃₃₃、不同生育期微喷灌量对麦茬复播谷子蛋白质及其3类氨基酸、脂肪、淀粉、纤维品质性状的影响均存在极显著差异(P<0.01)。其中PP₃₃₃在8叶期以1.2%浓度喷施可显著提高蛋白质含量、8种必需氨基酸、4种半必需氨基酸、3种非必需氨基酸平均含量；除色氨酸性状外，蛋白质及其他14种氨基酸含量在0.8%～1.2%浓度范围喷施PP₃₃₃均优于清水喷施(对照)；4叶期以1.0%、0.8%浓度喷施PP₃₃₃分别有利于脂肪、淀粉含量的提高。随微喷灌水量的增加蛋白质含量及其8种必需氨基酸、4种半必需氨基酸、3种非必需氨基酸平均含量基本呈现下降趋势，除半胱氨酸、色氨酸性状外，蛋白质、3类氨基酸平均含量及其13种氨基酸含量、脂肪含量均以生育期微喷灌量0.0...