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1.
Soybean rust, caused by Phakopsora pachyrhizi Sydow, is a severe foliar disease of soybean [Glycine max (L.) Merr.] that occurs throughout most soybean producing regions of the world. The objective of this research was to evaluate selected soybean genotypes for resistance to soybean rust in Vietnam. Five field experiments in Vietnam were completed from 2006 to 2009. The area-under-the-disease-progress-curve (AUDPC) was calculated for each soybean genotype based on four disease assessments taken during the reproductive growth stages. AUDPC units among soybean genotypes in each experiment differed (P < 0.05). Over the five experiments, the resistant check DT 2000 was most often the genotype with the lowest AUDPC units while the sources of rust resistance (Rpp1-5) did not always have low AUDPC units in each experiment, although PI 230970 (Rpp2) appeared to be more stable. A few genotypes with non-characterized genes for resistance, such as PI 398998, PI 437323, and PI 549017, had the lowest AUDPC units in at least one of the experiments. These genetic resources may be useful for host plant resistance studies and breeding soybeans for rust resistance in Vietnam and other locations like Brazil and the United States that have more recently been inundated with soybean rust. A significant (P < 0.001) experiment × genotype interaction was found when the AUDPC data of 14 soybean genotypes tested in Experiments 1, 2, and 3 were combined and analyzed. This result indicates the potential importance of changing fungal races and/or biotypes that occur in the rust population.  相似文献   

2.
向日葵锈病严重影响向日葵的产量。为了找到抗锈病相关基因,根据已知NBS-LRR型抗病基因保守结构域P-loop和GLPL设计简并引物,以接菌的抗病向日葵品种CM29叶片的cDNA为模板进行扩增。通过克隆转化得到10个具有连续开放阅读框的RGA,经系统进化分析将其分为TIR-NBS-LRR和non-TIR-NBS-LRR两种类型。对其氨基酸序列进行多重序列比对结果显示所获得的RGA具有典型的NBS-LRR型抗病基因保守结构域即P-loop、kinase-2a、kinase-3a和GLPL结构。运用BLASTX分析这些结果,表明其RGA与已知的抗病基因相应保守区域的同源性为18.1%～51.1%,说明它们可能与抗病功能基因具有密切联系。  相似文献   

3.
我国部分地区小麦生产品种和后备品系抗秆锈病状况分析   总被引：1，自引：1，他引：0  
2008-2009年间对来自我国小麦主要生产种植区15个省份的182份小麦生产品种和后备品系进行了苗期与成株期抗秆锈病鉴定,研究结果表明：在供试的品种（系）中,114份对秆锈病表现抗性,占供试材料的62.64%,其中来自东北春麦区、北方冬麦区和黄淮海冬麦区的品种（系）对秆锈病抗性较强,部分地区材料对秆锈病的抗性较差,甚至江苏省的13份品种（系）对秆锈病全部感病,这表明虽然我国当前小麦生产品种和后备品系对秆锈病的抗性普遍较强,但仍然存在有相当数量的感病品种,秆锈病发生与流行的威胁依然存在。  相似文献   

4.
向日葵籽粒锈斑病又称“水锈病”，是近几年向日葵生产上出现的一种新病害，严重影响向日葵籽的商品性，制约着产业的发展。本研究在向日葵籽粒锈斑发生严重的内蒙古巴彦淖尔市乌拉特前旗先锋镇和五原县新公中镇试验点调查取样，评价了44份向日葵品种（39份食葵品种与5份油葵品种）的籽粒锈斑抗性，结果表明：乌拉特前旗试验点供试食葵品种中，只有赛瑞1号单盘平均籽粒锈斑率低于25%；另外共有6份品种（包括JK103、LJ188和LD5009等），单盘平均籽粒锈斑率介于25%~50%之间；其余品种的单盘平均籽粒锈斑率都在50%以上。就严重度而言，共有20份品种籽粒锈斑的严重度鉴定为1级，但是其平均籽粒锈斑率却介于17.30%~88.63%之间；其余品种的严重度均为2级以上。五原试验点的调查结果表明，供试向日葵品种的单盘平均籽粒锈斑率介于61.02%~99.63%之间，均显著高于乌拉特前旗试验点相同品种的调查结果；但是就严重度而言，只有10份品种籽粒锈斑的严重度为1级，以3638C为代表。而供试的5份油葵品种中，除了XKS2029外，其余4份品种的单盘平均籽粒锈斑率均低于25%。同时，不同播种时间下同一品种的籽粒锈斑发生程度也呈现出明显的差异，如SH361品种单盘平均籽粒锈斑率从5月27日播种的34.49%上升到6月20日的98.47%；相应的严重度也从1级上升到4级，说明播期不同对籽粒锈斑发生程度也有明显的影响。  相似文献   

5.
With continuous outbreaks of stripe rust (Puccinia striiformis f. sp. tritici) epidemics and rapid breakdown of deployed resistance in bread wheat (Triticum aestivum L.) cultivars in North West Plains Zone (NWPZ) in India warrant knowledge and deployment of new and durable sources of resistance to stripe rust. Bread wheat cultivar PBW 343, until recently the most widely cultivated wheat variety in India, is now highly susceptible to stripe rust (score 9 on a 1–9 scale), whereas PBW 621 (score 5.05–5.65) and HD 2967 (score 5.40–6.20) show low levels of resistance. We conducted an experiment, spanning three crop seasons (2013–2014 to 2015–2016), in which parental lines, F1 and F2 populations, F3 and F4 families from two bread wheat crosses, PBW 621/PBW 343 and HD 2967/PBW 343 were generated and evaluated for stripe rust resistance against a virulent pathotype. While the F1 revealed partial dominance, the segregation pattern for stripe rust resistance in F2 and F3 showed transgressive segregation for resistance in both crosses. Chi-square analysis indicated that resistant segregants possessed two genes, one contributed by PBW 621 or HD 2967 (depending on the cross) and the other, unexpectedly but obviously, came from the most susceptible cultivar, PBW 343. Possible genetic mechanisms for this residual resistance and implications for breeding programs are discussed.  相似文献   

6.
Puccinia striiformis Westend. f. sp. tritici(Pst) pathotype CYR34 is widely virulent and prevalent in China.Here, we report identification of a strpie rust resistance(Yr) gene, designated Yr041133, in winter wheat line 041133. This line produced a hypersensitive reaction to CYR34 and conferred resistance to 13 other pathotypes. Resistance to CYR34 in line 041133 was controlled by a single dominant gene. Bulked segregant RNA sequencing(BSR-Seq) was performed on a pair of RNA bulks generated by pooling resistant and susceptible recombinant inbred lines. Yr041133 was mapped to a 1.7 c M genetic interval on the chromosome arm 7 BL that corresponded to a 0.8 Mb physical interval(608.9–609.7 Mb) in the Chinese Spring reference genome. Based on its unique physical location Yr041133 differred from the other Yr genes on this chromosome arm.  相似文献   

7.
The aim of this work was to identify Vicia faba germplasm resistant both to rust and chocolate spot. A collection of 43 accessions of V. faba previously identified as chocolate-spot resistant was evaluated for rust and chocolate spot resistance in Egypt and in Spain. The genotype and genotype × environment (GGE) biplot analyses allowed the selection of 11 accessions resistant to both diseases in those locations. These 11 accessions were evaluated for rust in an additional field trial in Spain, all performing better than the susceptible check. The joint analysis of the 11 accessions in the four field trials where they had been evaluated revealed no significant effects either for genotype, environment or the genotype × environment interaction. They are hence promising sources of resistance, both for their low severities and their stable responses across the studied environments. This collection was also tested under controlled conditions against the Egyptian and the Spanish isolates of rust present in the field trials further underlining the stable performance of these genotypes. Finally, the effect of previous infection with chocolate spot on rust resistance was assessed under controlled conditions and no influence of it was found.  相似文献   

8.
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9.
锈病是影响花生产量和品质的主要真菌性病害。本研究以“中花10号× ICG 12625”构建的重组自交系群体（RIL）为材料,在武昌和阳逻两个环境中对其F8群体进行锈病抗性鉴定,获得了8份抗锈病材料（QT0348、QT0368、QT0400、QT0402、QT0419、QT0458、QT0463和QT0485）。利用前期构建的遗传图谱进行QTL分析,检测到10个与锈病抗性相关的QTL,贡献率为4.54%~10.78%,分布于7条染色体上。其中,qBB06.1和qBB06.4为重复一致的QTL,贡献率为10.76%。根据侧翼标记在物理图谱进行比对,发现对应区段含有193个基因,其中178个基因被注释,功能注释基因中有1个NBS-R基因。本研究结果为花生抗锈病的遗传改良奠定了基础。  相似文献   

10.
The present work aimed to study the effect of saccharin and ulvan against rust in artificially inoculated plants and against both rust and angular leaf spot (ALS) in naturally infected bean plants. In the greenhouse, bean plants of cv. Guará (susceptible) and FT-line (rust resistant) at first trifoliate leaf stage were sprayed with saccharin (0.24 mg mL−1) or ulvan (1 or 10 mg mL−1), and inoculated with Uromyces appendiculatus six days after spray. Both compounds provided an intermediary level of protection. They reduced at a similar extent the number, diameter and particularly sporulation of rust pustules in susceptible plants, suggesting that mechanisms of resistance operate at latter stages of fungus colonization. Three follow-up experiments were carried out under natural infection conditions during the spring 2009 and 2010, and summer/autumn 2010. ALS was observed during all three outdoor pot experiments, whereas rust occurred only during the spring 2009 and 2010. Saccharin sprayed every 14 days was able to protect bean plants against rust during the three experiments, whereas significantly reduced ALS only during summer/autumn and spring 2010. On the other hand, ulvan at a reduced dose rate (1 mg mL−1) did not affect significantly the epidemiological development of both diseases. Increase in seed weight was observed when saccharin-treated plants were infected after pre-flowering, but not when rust infection occurred earlier. Possible reasons why such trade-offs can be obtained in certain circumstances are discussed.  相似文献   

11.
为了解寡糖诱导向日葵抗锈病过程中的信号转导途径,利用寡糖、水杨酸（SA）、茉莉酸（JA）预先喷雾处理向日葵叶片,1d后接种锈菌,通过对植株体内脂氧合酶（LOX）活性及SA含量的测定,并通过RT-PCR对SA、JA信号途径的标记基因PR5和PDF1.2等表达水平进行测定,初步确定诱导抗性表达的信号转导途径。结果表明：经寡糖诱导后,向日葵叶片内LOX活性降低,SA含量上升,且诱导水杨酸途径标记基因PR5表达量增加。结果说明寡糖诱导向日葵抵抗锈病主要与SA介导的信号途径有关。  相似文献   

12.
Inoculation in the glasshouse revealed marked differences in resistance to both ryegrass mosaic virus (RMV) and crown rust (Puccinia coronata Corda) among eight unselected populations of Italian ryegrass (Lolium multiflorum Lam.). Two generations of selection for crown rust resistance led to a significant improvement in all eight populations, while one generation of selection for RMV gave a more variable response. Frequency distributions of individual genotype scores suggested that much of the resistance to crown rust was under the control of one or two genes with major effects, while resistance to RMV appeared to be controlled by a large number of genes each having a small effect. In the field, resistance to RMV meeisured after 20 months was strongly correlated with that obtained in the glasshouse. Natural infection by crown rust in the field was too low to reveal any differences between populations, although three populations from the Po Valley region of Northern Italy became heavily infected with Puccinia recondita. Selection for disease resistance significantly reduced the persistency of three populations, but that of four others was unaffected and one showed a significant improvement. Selection reduced water-soluble carbohydrate (WSC) levels in spring slightly but significantly from 27.6 to 25.8% WSC overall. These results emphasize that agronomic performance must be monitored during selection for disease resistance.  相似文献   

13.
Thirty sweet corn (Zea mays) hybrids were evaluated for resistance to rust (Puccinia sorghi Schr.) for 3 years in an artificially inoculated field plot at St Paul, Minnesota. On the basis of visual determinations of rust severity, these cultivars were ranked according to level of resistance. All of them allowed at least some rust to develop, but the degree of final rust severity varied considerably. Correlation coefficients between the rust severity scores recorded for the hybrids in all three pairs of years were 0·68 (1978–1979), 0·79 (1978–1980) and 0·86 (1979–1980). Spearman's rank correlation coefficients were 0·76, 0·89 and 0·82, respectively, for the same comparisons.  相似文献   

14.
We examined the effect of saccharin on the systemic acquired resistance (SAR) response of soybean to the fungus Phakopsora pachyrhizi, the causal agent of soybean rust. Plants were grown hydroponically in half-strength Hoagland’s solution and were challenged with the pathogen 1, 5, 10 and 15 d after treatment with 3 mM saccharin applied either as a foliar spray or a root drench at the 2nd trifoliate (V3) and early reproductive (R1) stages. Plants were destructively harvested and assessed for visible rust symptoms 2 wk after inoculation. Mode of saccharin application was a significant factor influencing the severity of rust infection. Saccharin applied as a root drench was more effective than the foliar spray treatment at inducing SAR, with increased resistance observed 1 d after application. Systemic protection against rust infection was still apparent 15 d after application of saccharin as a root drench. In contrast, foliar treatment with saccharin did not increase systemic protection until 15 d after treatment. When systemic protection was induced by the application of saccharin in either manner, there was no significant reduction of plant growth, except when plants were inoculated 15 d after the saccharin application as a root drench at the R1 stage of development.  相似文献   

15.
大豆锈病研究进展   总被引：1，自引：0，他引：1  
1899年在中国的吉林首次报道了由豆薯层锈菌(Phakopsora pachyrhizi Syd)引起的大豆锈病。20世纪60年代大豆锈病成为热带、亚热带地区大豆生产中最严重的病害，进入本世纪后，大豆锈病成为世界性病害。对大豆锈病较为系统的研究始于20世纪70年代，目前对大豆锈病的病原菌分类、分布及其寄主、病原夏孢子生物学特性、病害流行、抗锈资源鉴定、抗锈遗传都有较为详细的研究，但对冬孢子的作用、生理小种的分化和鉴定、锈菌的交替寄主、锈病的初侵染源都还缺乏深入的研究，至今尚未发现对锈菌免疫的抗源，限制了锈病的防治和抗锈遗传育种的开展。  相似文献   

16.
大豆锈病越冬区气候区划研究   总被引：2，自引：1，他引：2  
根据1951-2001年间全国743个气象站点的气象数据,结合大豆锈病越冬所需气候条件,采用地理信息系统分析获得了大豆锈病在我国越冬区区划图,以供我国各个地区统一协调管理大豆锈病时参考使用.根据生物气候相似距原理,以琼海为中心,以计算的前一年12月初到下一年2月底的时间段内各个旬均温、月最高温、月最低温、旬降雨量为气候要素,计算琼海与其余742个气象站点的气候相似距,用地理信息系统软件Arcmap对相似距值按Kriging法进行插值,生成的地图表明,大豆锈病可在海南岛、广东南部较大范围内越冬,而云南和广西只有局部地区适合大豆锈病越冬.该区划结果需要进一步实地调查验证.  相似文献   

17.
Little information is available regarding the efficacy and timing of modern fungicides for the control of plum rust. In this study, modern fungicides, including triazoles, strobilurins, and benzimidazoles, and a classic fungicide (chlorothalonil) were tested under both greenhouse and field experiments. Excellent disease control was obtained by the pre-inoculation application of all fungicides in the greenhouse experiments. However, only triazoles (tebuconazole, difenoconazole, flusilazole and hexaconazole) were effective when applied up to 6 or 7 days after inoculation. Unexpectedly, strobilurins (azoxystrobin and trifloxystrobin) and benzimidazoles (thiophanate-methyl and carbendazim) were not effective when applied at any time after inoculation. In field experiments, early-season fungicide applications effectively inhibited primary infections; however, these applications provided no apparent benefit in preventing secondary infections and premature leaf fall later in the season. All fungicides provided better control over the season and significantly reduced premature leaf fall when applied immediately after rust pustules (uredinia) were first observed. It is suggested that all fungicides tested in this study can be used for plum rust control. Disease monitoring data indicated that disease severity remained low throughout May but dramatically increased in early June. Mid-May is evidently the best time to initiate fungicide sprays against rust on plums; the spray should be applied before or when rust pustules are first observed and when rust is present at low severity.  相似文献   

18.
Effects of leaf rust (caused by Puccinia triticina f. sp. tritici Eriks.) and powdery mildew [caused by Blumeria graminis (DC.) E. O. Speer f. sp. tritici Em. Marchal], on performance of 50 soft red winter (SRW) wheat (Triticum aestivum L) cultivars were evaluated under natural field conditions. Widely grown cultivars released from 1919 to 2009 with varying disease resistance were grown in split-plot experiments in 2010 and 2011. Treated replications received seed treatments of triadimenol, captan and imidacloprid and foliar applications of propiconazole and prothioconazole + tebucanazole fungicides. Non-treated replications received only tebucanazole + metalaxyl + imazalil seed treatments. Final mean disease severity, agronomic, yield-related traits, yield components and spike characteristics were analyzed to determine individual and combined effects of leaf rust and powdery mildew on the cultivars. Yield losses as high as 54% were observed in the susceptible cultivar Red May. Average yield losses ranged from 1% to 21%. Yield losses primarily due to powdery mildew were as high as 14%, and losses primarily due to leaf rust were as high as 33%. Powdery mildew had the largest negative correlation with harvest index and seeds/spike. Leaf rust was most negatively correlated with plant biomass and harvest index, with a less consistent negative relationship with kernel weight.  相似文献   

19.
Soybean rust, (Phakopsora pachyrhizi), currently the most devastating disease of soybeans worldwide, is known to challenge single resistance genes deployed against it and therefore, disease tolerance is indisputably the most viable measure in controlling the pathogen. Studies were conducted at Namulonge in Central Uganda to assess the level of tolerance to soybean rust among selected elite soybean lines. Seven elite lines together with three local checks were tested in a split-plot design where some plots were protected with fungicide to estimate the level of tolerance to soybean rust. The experiment was conducted for three cropping seasons beginning second rains of 2005. A rust tolerance index (RTI) was computed for each test line as the ratio of yield from unprotected plots to yield from protected plots. The study showed that high levels of tolerance to soybean rust were present in the test lines. The soybean lines that showed high levels of tolerance included MNG 10.3 and MNG 3.26 all showing RTIs higher than 0.93. These lines also out-yielded the local checks by about 400 kg ha−1 and are recommended for multi-location testing.  相似文献   

20.
Breeding for tolerance to soybean rust is potentially one of the solutions to combating soybean rust; however, very little progress in tolerance breeding has been documented. Fourteen pre-selected genotypes were evaluated in a sprayed versus unsprayed split-plot trial conducted over three seasons for their tolerance to soybean rust. Different assessments of tolerance were compared for their effectiveness in discriminating between genotypes. Conventional methodology using a yield loss % index for assessing tolerance produced results which were poorly correlated with each other over seasons, which likely accounts for the historic lack of breeding success. This study has used the superiority measure (Pi) of Lin and Binns and the ecovalence statistic (Wi) of Wricke in a biplot to identify the most tolerant genotypes. A novel statistic (WiPi) has been generated from this biplot which facilitates the simultaneous selection for general performance and yield stability of genotypes under a range of rust stress conditions.  相似文献   

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