珊瑚菜柄锈菌性孢子阶段的发现及北沙参锈病研究简报

 北沙参(植物名珊瑚菜Glehnia littoralis)为名贵药材,锈病是北沙参的重要病害,其病原为珊瑚菜柄锈菌Puccinia phellopteri Syd.。该菌虽早有记述,但迄今只见有冬、夏孢子阶段的报道,对其生活史及侵染循环尚不清楚。     

玉米南方型锈病发生规律与防治技术初步研究

采用田间调查和试验的方法,着重研究了玉米南方型锈病病菌多堆柄锈菌夏孢子发芽与环境条件的关系,玉米不同生育期的感病性和病害的初侵染来源,并探讨了控制该病为害的主要技术途径。     

小驳骨锈病的发生与防治研究初报

1999年在南宁市郊发现由柄锈菌 (Puccinia sp)引起的小驳骨锈病 ,发病程度逐年加重 ,传播范围逐渐扩大。病菌冬孢子在 RH10 0 % +水滴条件下 (2 5℃ )易萌发 ,病害盛发期为春末夏初及秋末冬初。用修剪清除病枝叶、清除病枝叶并结合施肥管理、 0 .5°Be石硫合剂、 30 0 0倍 2 0 %粉锈宁乳油 4种方法进行防治试验 ,防治效果分别为 10 0 %、 10 0 %、 5 1.6 %、6 4 .5 % ,以第 2种防治方法效果最佳     

玉米南方锈病发生温度范围测定

玉米南方锈病由玉米多堆柄锈菌(Puccinia polysora Underw.)引起,主要分布在热带和亚热带地区,但随着全球气候变暖,其发生范围不断扩大,对玉米生产的影响也随之扩大。对于该病害发病温度范围的测定有助于病害发生范围的区划和病害预防工作的进行。试验将多堆柄锈菌接种到供试玉米材料‘郑单958’上,置于不同温度下的光照培养箱中培养并观察发病情况,从而确定出玉米南方锈病的发病温度范围以及发病最适温度范围。试验结果表明:玉米南方锈病的发病温度范围为15~31℃,最适温度范围为24~27℃。     

大蒜锈病的发生和防治

大蒜是人们喜爱的蔬菜之一,在神农架林区农村家家都有种植,但近几年大蒜锈病发生呈加重趋势,成为我区大蒜主要病害,发病率在80%以上,发病面积在200 hm2以上,感病大蒜蒜头小,易开裂,严重影响大蒜的产量和质量,农民强烈要求对其进行及时控制,为了科学地对我区大蒜锈病进行防治,笔     

夏谷锈病的发生与防治

夏谷锈病的发生与防治贺献林（河北省涉县农业局植保站０５６４００）谷子锈病是近几年夏谷的一种主要病害。在邯郸市各地均有发生，而山区发生尤为严重，一般年份病株率１５～４０％，重发时病株率达１００％，产量损失１２～２０％，甚至更高，我们自１９９２年开始对其...     

荷兰豆锈病的发生与防治

荷兰豆是近几年来农村普遍栽培的菜用豆类之一 ,它既增加农民的收入 ,又丰富了城乡居民的物质生活。但是荷兰豆锈病却是影响荷兰豆生长的主要病害之一 ,病株叶片早衰早落 ,豆荚的食用价值大减 ,严重时减产可达 5 0 %以上 ,因此 ,认真对待是十分必要的。1　病害特征　　主要危害叶片 ,影响光合作用 ,严重时叶柄和豆荚也受害 ,病斑初期常出现黄白色小点 ,随而变成红褐色 ,隆起呈小疮疱斑 ,外围常有黄色晕环。有时老病斑四周有一圈新的红褐色疱状物 (病源菌的夏孢子堆 ) ,表皮破裂后散发出红褐色粉末 ,病株茎叶上有园形褐色小斑点。后期叶片 ,…     

玉米锈病的研究进展

文章对玉米锈病的病原菌类型和症状作了详细描述 ,介绍了该病在我国近年的发生危害情况 ,并提出防治对策     

草坪锈病的发生特点与防治

锈病可以侵染多种冷季型草坪,是一种严重的真菌病害.它主要危害草地早熟禾、多年生黑麦草、狗牙根、高羊茅、台湾草(细叶结缕草、天鹅绒草)、马蹄金等,其中尤以草地早熟禾、黑麦草受害严重.草坪草受锈病危害后,生长不良,叶片和茎变成不正常的颜色,生长矮小,光合作用下降,严重时导致草坪死亡.     

芍药病害的发生及其综合防治

根据调查结果：在江西芍药生长过程中常发生5种病害，对其病原、症状进行了描述，并调查了发病规律，在防治方法上提出综合防治，多从改善生态环境与药剂相结合，达到控制病害发生与为害。     

Inheritance of rust resistance in Macroptilium atropurpureum

Sixteen accessions of Macroptilium atropurpureum showed a range of reaction types when seedlings were inoculated with a single-urediniospore isolate of Uromyces appendiculatus (rust). Analysis of F₂ families of crosses with the susceptible cv. Siratro showed that in seven accessions resistance was dominant, regulated by a single locus in four of these but by more than one locus in the three others. At least three of these loci were identified as non-allelic. In one accession resistance was near-recessive and regulated at a single locus, while combinations of dominant and recessive alleles at different loci explained the segregation of resistance in other accessions. Loci with partial dominance and expressivity varying with environment were also observed. There was some evidence that the expression of resistance could be temperature sensitive and that the fungus exhibited differential virulence.     

Mapping of Aegilops umbellulata‐derived leaf rust and stripe rust resistance loci in wheat

Aegilops umbellulata, a non‐progenitor diploid species, is an excellent source of resistance to various wheat diseases. Leaf rust and stripe rust resistance genes from A. umbellulata were transferred to the susceptible wheat cultivar WL711 through induced homoeologous pairing. A doubly resistant introgression line IL 393‐4 was crossed with wheat cultivar PBW343 to develop a mapping population. Tests on BC₂F₇ RILs indicated monogenic inheritance of seedling leaf rust and stripe rust resistance in IL 393‐4 and the respective co‐segregating genes were tentatively named LrUmb and YrUmb. Bulked segregant analysis placed LrUmb and YrUmb in chromosome 5DS, 7.6 cM distal to gwm190. Aegilops geniculata‐derived and completely linked leaf rust and stripe rust resistance genes Lr57 and Yr40 were previously located in chromosome 5DS. STS marker Lr57/Yr40MAS‐CAPS16 (Lr57/Yr40‐CAPS16), linked with Lr57/Yr40 (T756) also co‐segregated with LrUmb/YrUmb. Seedling infection types differentiated LrUmb from Lr57. Absence of leaf rust‐susceptible segregants among F₃ families of the intercross (IL 393‐4/T756) indicated repulsion linkage between LrUmb and Lr57. YrUmb expressed a consistently low seedling response under greenhouse conditions, whereas Yr40 expressed a higher seedling response. Based on the origin of LrUmb/YrUmb from the U genome and Lr57/Yr40 from the M genome, as well as phenotypic differences, LrUmb and YrUmb were formally named Lr76 and Yr70, respectively. These genes have been transferred to Indian wheat cultivars PBW343 and PBW550, and advanced breeding lines are being tested in state and national trials.     

Genetics of resistance to wheat leaf rust, stem rust, and powdery mildew in Aegilops sharonensis

Aegilops sharonensis (Sharon goatgrass) is a wild relative of wheat and a rich source of genetic diversity for disease resistance. The objectives of this study were to determine the genetic basis of leaf rust, stem rust, and powdery mildew resistance in A. sharonensis and also the allelic relationships between genes controlling resistance to each disease. Progeny from crosses between resistant and susceptible accessions were evaluated for their disease reaction at the seedling and/or adult plant stage to determine the number and action of genes conferring resistance. Two different genes conferring resistance to leaf rust races THBJ and BBBB were identified in accessions 1644 and 603. For stem rust, the same single gene was found to confer resistance to race TTTT in accessions 1644 and 2229. Resistance to stem rust race TPMK was conferred by two genes in accessions 1644 and 603. A contingency test revealed no association between genes conferring resistance to leaf rust race THBJ and stem rust race TTTT or between genes conferring resistance to stem rust race TTTT and powdery mildew isolate UM06-01, indicating that the respective resistance genes are not linked. Three accessions (1644, 2229, and 1193) were found to carry a single gene for resistance to powdery mildew. Allelism tests revealed that the resistance gene in accession 1644 is different from the respective single genes present in either 2229 or 1193. The simple inheritance of leaf rust, stem rust, and powdery mildew resistance in A. sharonensis should simplify the transfer of resistance to wheat in wide crosses.     

Focus expansion of bean rust in cultivar mixtures

Radial expansion of foci in mixtures of susceptible and resistant bean cultivars was studied at two sites in Ethiopia. The foci expanded in a wave-like fashion. At Ambo (1990), radial expansion velocity ranged from 6 cm per day in mixtures with 20% susceptible plants to 15 cm per day in plots with the susceptible plants only. At Debre Zeit, the velocity ranged from 3 cm per day in a mixture with 20% susceptible plants to 16 cm per day in plots with 100% susceptible plants. At both sites the radial expansion velocity of foci correlated linearly with the logarithm of the fraction of susceptible plants in the mixture. Velocities of focus expansion at Ambo and Debre Zeit were approximately equal in plots consisting of susceptible plants only. At lower proportions of susceptible plants the velocities at Debre Zeit were lower than at Ambo. Indications were given as to the environmental factors responsible for the observed difference between sites. At each site, the variation between plots showed a clear spatial pattern, probably due to environmental factors.     

Breeding cereals for rust resistance in Australia

Rust diseases have caused significant losses to Australian cereal crops, and continue to pose a serious threat. Because Australian cereal crop yields are generally low, genetic resistance remains the most economical means of rust control. Resistant cultivars also contribute significantly to reducing over-summer rust survival. A policy of releasing only rust resistant wheats in northern New South Wales and Queensland has resulted in industry-wide protection from rust in this region for the past 40 years. The Australian Cereal Rust Control Program conducts annual pathogenicity surveys for all cereal rust pathogens, undertakes genetic research to identify and characterize new sources of resistance, and provides a germplasm screening and enhancement service to all Australian cereal breeding groups. These three activities are interdependent, and are closely integrated with particular emphasis on linking pathology and genetics to ensure breeding outcomes. Recent changes in the wheat rust pathogens, including the development of virulences for Yr17 , Lr24 , Lr37 and Sr38 resistance genes, and the introduction of a new pathotype of the wheat stripe rust pathogen, have provided new and significant challenges for wheat rust resistance breeding. Similar challenges exist in breeding barley and oats for rust resistance. Examples are discussed to illustrate the ways in which rust isolates are providing information that can be used in breeding for rust resistance. In future, as more markers linked to durable rust resistance sources become available, it is likely that the use of marker-assisted selection will become more common-place in rust resistance breeding.     

Life-table analysis of faba bean rust

In controlled near-optimum conditions (18 °C), monocyclic sporulation capacity and spore infection efficiency were assessed for faba bean rust on the first and second leaves of field bean. After a latency period of 8–10 days, lesions sporulated duringc. 50 days. Spore production on the second leaf,c. 9×10⁴ spores per lesion, was two times as high as spore production on the first leaf. Infection efficiency was similar for both leaf layers, with a mean value of 0.11 lesion per inoculated spore. Infection efficiency decreased strongly when spores originated from mother lesions older than 20 days. Three life-table statistics (the net reproduction numberR _o , the mean generation timeT _g , and the maximum relative growth rater _max ) were calculated.R _o was larger andT _g was longer for the second than for the first leaf, butr _max was nearly the same for both leaf layers (0.31–0.33 day^–1).r _max was compared with the exponential growth rater measured in a field experiment. From the difference between the two rates, the fraction of inoculum lost in field conditions was estimated at 0.54–0.94. The life-table statistics were also compared to those of other legume rusts, and implications of life-table analysis for comparative epidemiology were discussed.     

Leaf rust resistance gene lr34 associated with nonsuppression of stem rust resistance in the wheat cultivar canthatch

ABSTRACT The common wheat cultivar Thatcher and the backcross derivative Canthatch are moderately or fully susceptible to several races of stem rust because of a suppressor on chromosome 7DL that inhibits the expression of the relevant resistance gene(s). The incorporation of leaf rust resistance gene Lr34 into 'Thatcher' is known to enhance stem rust resistance. The effect of this gene in a 'Canthatch' background and its relationship with the 7DL suppressor were determined by replacing chromosome 7D of 'Canthatch' with 7D of 'Chinese Spring', which possesses Lr34 on the short arm. 'Canthatch' nullisomic 7D was crossed with 'Chinese Spring', followed by a succession of backcrosses to the nullisomic recurrent parent. Homozygous resistant disomic and monosomic substitution lines were recovered that exhibited the same resistant reaction as that of 'Thatcher' possessing Lr34 and as that of 'Canthatch' nullisomic 7D, in which the 7DL suppressor is absent. The results indicate that, in 'Canthatch', Lr34 permits expression of resistance genes normally inhibited by the 7DL suppressor. Furthermore, it is likely that, in 'Thatcher' and 'Thatcher' back-cross derivatives, Lr34 inactivates the 7DL suppressor.     

我国玉米锈病分布与分子检测

通过分析相关文献,概述了我国玉米锈病的发生与分布;介绍了普通玉米锈病已经遍布我国玉米各种植区。南方玉米锈病也从最初只在两个省份发生,发展到目前在多省份暴发。说明玉米锈病适应能力较强,而其他未报道发生的玉米种植区也存在暴发流行的风险。因此,应做好玉米锈病的监测工作。同时,介绍了监测玉米锈病的分子检测体系。