西藏地方小麦品种曲白春的抗条锈性遗传分析

为了明确曲白春的抗条锈性遗传规律,并为其在抗病育种中的合理利用提供理论指导,本研究以曲白春与川麦28构建遗传分析群体,以曲白春与中国春构建等位分析群体,用CYR33温室条件下苗期人工接种遗传分析群体,用混合流行优势小种大田条件下成株期人工诱发接种遗传分析群体和等位分析群体,同时对曲白春的抗条锈性进行遗传分析,并用小麦抗条锈基因Yr18的特异性分子标记对曲白春进行分子检测。结果表明,曲白春苗期对CYR33的抗性由一对显性基因控制,成株期对小麦条锈菌的抗性由2对独立显性核基因控制,即由小麦抗条锈基因Yr18和一对未知的小种专化性抗条锈基因控制。     

Evaluation of the SPAD Value in Faba Bean (Vicia fabaL.) Leaves in Relation to Different Fertilizer Applications

Abstract

The correlations of the reading of a portable chlorophyll meter (SPAD-502) with the chlorophyll and N contents of leaves of two faba bean (Vicia fabaL.) cultivars, Japanese (Ryousai-issun) and Egyptian (Cairo 241), were examined. The SPAD readings positively correlated (ρ<0.01) with the chlorophyll contents and the r² values were 0.99 and 1.00 for Ryousai-issun and Cairo 241, respectively. A close linear relationship (ρ0.001) was observed between SPAD reading and total leaf N content at the pod development stage of faba bean plants with r² = 0.88 and 0.99 for Ryousai-issun and Cairo 241, respectively. The SPAD reading was the highest in the 2^nd to 4^th leaves counted from the top (the youngest fully expanded leaves). The changes in leaf chlorophyll content of both cultivars from 3 weeks after transplanting to the ripening stage showed an incomplete “M” type curve. SPAD readings were significant¬ly higher in Ryousai-issun than in Cairo 241 throughout the growth season. Organic fertilizers application improved faba bean plant growth. These results suggest that the SPAD-502 chlorophyll meter can be used to measure chlorophyll and nitrogen contents of faba bean leaves for quick screening faba bean genotypes.     

用于生物防治水稻纹拮病的抗细菌的筛选

 分别从健康的水稻植株、感染纹枯病植株、根际土壤、秧田水和菌核上分离出能拮抗水稻纹枯病的假单胞菌属(Pseudomonas spp.)和芽胞杆菌属(Bacillus spp.)的细菌菌株，大多数菌株在室内试验中对菌丝生长有抑制作用，有的菌株在温室试验中起抑制病害和对植株有保护作用， 有的(1／49) 具有促进秧苗生长的作用。纹枯病的病斑相对长度与病害发生率密切相关(r²=0.33，P=0.01)， 与抑菌圈大小(r²=0.3)和离体叶片病斑大小(r²=0.12) 无相关，植株干重与病斑相对长度和发病率均无显著相关(r²=0或0.1)。     

139份大麦种质材料苗期和成株期抗白粉病鉴定评价

为给培育大麦持续性抗白粉病品种提供有价值的抗源,利用7个大麦白粉病菌优势小种,在实验室条件下分别接种139份大麦品种(系),进行苗期抗性鉴定,同时于2009-2011年度在云南保山对参试品种(系)进行田间成株期抗性鉴定,并考查成株期抗病材料的农艺性状.结果表明,参试品种(系)在苗期对7个优势小种表现出48个不同的抗性反应谱,13个大麦品种(系)能抗所有参试的优势小种,22个大麦品种(系)能抗4～6个优势小种.25个大麦品种(系)具有成株期抗病性.大麦苗期抗性与成株期抗性并不完全一致,但苗期抗优势小种数较多的材料中,成株期表现抗性的也较多,5个苗期抗所有优势小种的大麦品种(系)均表现出成株期抗性.25个成株期抗病品种(系)中18个为二棱皮大麦,7个为多棱裸大麦,它们株高、穗长、穗粒数扣千粒重的变异系数较大,二棱皮大麦株高、穗长、穗粒数和千粒重的变异系数分别为10.3％、15.0％、12.0％和20.6％,多棱裸大麦分别为18.3％、26.4％、19.5％和22.8％.     

Genotypic response of common bean to natural field populations of bean fly (Ophiomyia phaseoli) under diverse environmental conditions

Bean fly is a significant pest of common bean in semi-arid areas of East Africa. Apart from inadequate moisture in the dry land, bean fly simultaneously contributes negatively thereby adversely affecting bean productivity. The objectives of this study were to (1) identify sources of resistance to bean fly available in landraces, (2) confirm stability of host plant resistance in drought stress and (3) determine the effect of drought stress and seasonal variation on common bean genotypes in relation to bean fly attack for adaptability to the semi-arid areas of East Africa. Sixty four genotypes including landraces, bean fly resistant lines and local checks were evaluated for seed yield, 100-seed weight, days to maturity, plant mortality and pupae in stem in an alpha lattice design with two replications. This was under drought stressed (DS) and non-stressed (NS) environments and two treatments (insecticide sprayed and natural infestation) for three cropping seasons between 2008 and 2009. Genotypes differed in their reaction to natural bean fly attack under drought stressed (DS) and non-stressed (NS) environments over different cropping seasons. However, the effect of bean fly appeared to vary between the long rains (LR) and short rains (SR). It was observed that an increase in number of pupae per stem resulted in a higher plant mortality. The range of seed yield was from 345 to 1704 kg ha⁻¹ under natural infestation and from 591 to 2659 kg ha⁻¹ under insecticide protection. Seed yield loss ranged from 3 to 69%. The resistance of most of the bean fly resistant lines seemed to break down in presence of DS owing to their dismal performance. Screening of genetic resources in common bean to breed for host plant resistance to bean fly offers high potential of success if researchers take full advantage of the diversity available within the landraces.     

Effect of Dwarfing Induced by Uniconazole-P on Snow Tolerance of the Faba Bean (Vicia faba L.)

Abstract

To clarify the effect of artificial dwarfing induced by uniconazole-P, a gibberellin biosynthesis inhibitor, on the snow tolerance of faba bean, we examined the snow damage, non-structural carbohydrate (NSC) concentration, and resistance to snow molds of the seedlings treated with uniconazole-P. Artificial dwarfing markedly decreased snow damage caused by continuous snow cover for 62 days. NSC concentration, which affects physiological snow tolerance and snow mold resistance, was lower in dwarfed plants than in non-dwarfed plants. However, there was no difference in the rate of decrease of NSC concentration between dwarfed and non-dwarfed plants under cold and dark conditions simulating snow cover. In inoculation tests, the lesions of Pythium iwayamai and Sclerotinia trifoliorum on the leaves detached from dwarfed plants were shorter than those on the leaves from non-dwarfed plants. In artificially dwarfed plants, the leaves were thicker and darker in color, and mesophyll cells were larger and denser than those in the non-dwarfed plants. Our findings suggest that the artificial dwarfing caused by uniconazole-P increased the resistance of the leaves to snow molds, thereby increasing snow tolerance, without increasing NSC concentration. The microstructural changes that occur with dwarfing may be a factor in snow tolerance.     

Both incidence and severity of white rust disease reflect host resistance in Brassica juncea germplasm from Australia,China and India

White rust (Albugo candida) is a highly destructive disease of oilseed Brassicas such as Brassica juncea and B. rapa, and has caused serious yield losses in Australia, China and India on both species. The first commercial B. juncea varieties are now being deployed in Australia, but their response to Australian strains of A. candida is yet to be defined under Australian field conditions. To identify useful sources of host resistance for Australia, China and India, in B. juncea, three field trials were undertaken in Western Australia. Forty-four B. juncea genotypes, viz. 22 from India, 12 from Australia and 10 from China, were tested. Varying levels of host resistance to Australian strains of A. candida (race 2) were identified among the genotypes from the three countries. Genotypes CBJ-001, CBJ-003 and CBJ-004 from China consistently showed high levels of resistance to A. candida on leaves across the three trials. Overall, the genotypes from China showed the best resistance, followed by the genotypes from Australia, with those from India being the most susceptible. The most susceptible genotypes were RL1359, RH30 and Seetha from India. It is noteworthy that both the incidence and severity of disease reflected varying levels of host resistance in the germplasm from the three countries, irrespective of whether screening was undertaken in the field using natural or artificial inoculation. Differentiation of resistance among these genotypes was similar to that we reported previously for artificially-inoculated seedlings or adult plants under glasshouse conditions, indicating that a choice of options is available to plant breeders to reliably differentiate host resistance among genotypes to white rust in B. juncea.     

134份四川小麦品种(系)的条锈病抗性评价

小麦条锈病是四川小麦生产中的第一大病害。为了系统掌握四川小麦品种和后备品系的条锈病抗性水平,给四川乃至全国小麦抗条锈病育种及品种的合理布局提供参考信息,利用7个条锈菌流行小种对134份四川审定品种和后备品系的苗期和成株期条锈病抗性进行鉴定。结果表明,四川小麦品种(系)在苗期对7个条锈菌小种CYR31、Su11-7、CYR29、Su11-4、CYR32、CYR33和V26(新致病类型)的抗性频率分别为92.4%、92.5%、89.3%、89.4%、87.3%、85.0%和82.8%;其中,76份品种(系)抗所有小种,占56.0%;此外,条锈菌新致病类型V26对四川小麦品种(系)的毒性已经超过当前的优势小种CYR32和CYR33。根据抗谱分析结果,将所有品种(系)分为四大类。其中,66.4%的品种(系)为全生育期抗性,17.9%为成株期抗性,9.7%表现为苗期抗性,6.0%表现为感病。表明四川小麦品种(系)整体抗性水平较高,但抗病类型相对单一。因此,需要进一步拓宽抗源,提高抗病基因的多样性;同时应逐步开展全生育期抗病基因和成株期抗病基因聚合育种,以提高品种抗病的持久性。     

甘肃省26个春小麦品种（系）苗期抗条锈基因分析及成株期抗病性评价

为明确甘肃省部分春小麦品种(系)苗期所含抗条锈基因,选用来自中国、印度等国家的24个具有不同毒性谱的条锈菌单孢菌系,分别接种于26个甘肃春小麦品种(系)及30个已知基因的载体品种上,进行苗期抗条锈病评价,并结合系谱分析推导苗期抗条锈基因.初步分析结果表明,银春8号等19个品种(系)含有Yr1及未知抗病基因,其余品种(系)含有未知抗病基因.成株期在甘肃陇南的田间抗条锈病评价结果显示,定西43可能具有成株抗病性,定E301、定9873、定鉴5、陇春26、陇春24、定西39、临麦30、宁9415具有慢条锈性.聚类分析与基因推导结果基本一致.     

General resistance against potato virus Y introduced into a commercial potato cultivar by genetic transformation with PVYN coat protein gene

Summary Transgenic cv. Folva potato plants expressing the coat protein gene of potato virus Y strain N (PVY^N) were produced usingAgrobacterium tumefaciens mediated transformation. Forty independent transformants were selected for resistance screening. Four clones showed complete resistance to mechanical inoculation with all the five PVY isolates tested: the PVY^N isolate from which the coat protein gene was derived, two PVY^O isolates, and two PVY^NTN isolates. Two of the fully resistant clones contained only one copy of the transgene, demonstrating that it is possible by genetic engineering to obtain highly virus resistant potato clones that can also be useful in future breeding programmes.     

Changes in race structure of Canadian populations ofPhytophthora infestans based on specific virulence to selected potato clones

Summary A collection of 80 isolates ofPhytophthora infestans, representing multilocus genotypes of the pathogen found in Canada from 1994 to 1996, was screened on a series of nine differential potato host cultivars to determine the physiological race of the isolates. A total of 28 pathotypes were found among the 11 genotypes present in the collection. There was a significant increase in the complexity of pathotypes from 1994 to 1996 which reflected the displacement of the US-1 genotype (mean of 2.2 host differentials infected) by the US-8 genotype (mean of 8.1 host differentials infected). Eighteen of the US-8 isolates could overcome all nine of the resistance genes tested. Virulence genes which overcame host resistance conferred by R8 were the rarest in the populations studied. The predominance of complex populations ofP. infestans in Canada implies that the introduction of cultivars with specific R genes for resistance would be an ineffective control measure. AAFC Contribution No. 901     

Analysis of host plant resistance to multiple Fusarium species associated with stalk rot disease in sorghum [Sorghum bicolor (L.) Moench]

Fusarium spp. is among the largest and most important pathogen groups that attack major grain crops including sorghum. The objectives of this study were to compare the virulence of Fusarium spp. associated with sorghum and examine the mode of resistance of genotypes to the disease. Eight Fusarium species – F. verticillioides, F. thapsinum, F. andiyazi, F. proliferatum, F. nyagamai, F. pseudoanthophilum, F. brevicatenulatum, and F. pseudonygamai – were studied using three sorghum genotypes under greenhouse condition. Three of these pathogens (F. verticillioides, F. thapsinum, and F. andiyazi) were selected for genetic analysis of resistance under field conditions. Sorghum genotypes with contrasting stalk rot reactions were selected for use in both the greenhouse and field experiments. Two weeks after flowering, plants were inoculated with liquid inoculum culture (5 × 10⁴ conidia ml⁻¹) of the different pathogens. Plants were harvested 4 weeks after inoculation and rated for disease severity on the basis of lesion length and number of nodes crossed by the lesion. Among the pathogens, F. thapsinum resulted in consistently higher disease scores in all genotypes under all environments. Likewise, genotype SC599 showed the greatest and most stable resistance as inbred as well as in hybrid combinations as shown by consistently high GCA for resistance to all pathogen species. We recommend that future screening exercises for Fusarium stalk rot resistance utilize F. thapsinum as the causal organism and include the resistant genotype SC599 as a control.     

转基因抗虫玉米对亚洲玉米螟的抗性评价

采用田间人工接虫鉴定方法,根据玉米抗螟性田间鉴定评价标准,研究转基因玉米Bt799和NC6304YGRR对亚洲玉米螟的抗性.心叶期接虫试验结果表明,以食叶级别作为评价参数,2种转基因玉米对亚洲玉米螟具有良好的抗性,食叶级别均为1级;2种非转基因玉米食叶级别均大于7级.吐丝期接虫试验结果表明,以单株虫孔数、单株活虫数、单株隧道个数及单株隧道长度作为评价参数,2种转基因玉米对亚洲玉米螟抗性均显著高于各自对应的非转基因玉米.转基因抗虫玉米Bt799和NC6304YGRR田间抗虫效果良好,均能保护玉米在整个生育期内不受亚洲玉米螟危害.     

中国小麦主栽品种抗条锈性评价与基因分析

为给全国小麦条锈病大区流行的预测预报和综合防控提供数据支持,在陕西杨凌设置当前流行小种CYR32和CYR33的混合病圃,在甘肃天水设置自然发病圃,对74个主栽小麦品种进行连续两年成株期抗病性鉴定,同时对其进行苗期室内分小种(CYR32和CYR33)和田间自然发病状态下的鉴定;分别选用Yr5、Yr9、Yr10、Yr15、Yr17、Yr18和Yr26等7个已知抗条锈病基因的分子标记进行基因检测。抗病鉴定结果显示,参试的74个小麦主栽品种中,无全生育期抗病品种,4个成株期抗病品种,10个在杨凌成株期抗病的品种在天水自然小种圃中有不同程度的感病;分子检测结果显示,参试小麦品种中24个品种含Yr9,4个品种带有Yr17,5个品种带有Yr26,未发现含Yr5、Yr10、Yr15和Yr18的小麦品种。这一结果表明,当前我国大面积种植的小麦品种抗条锈病水平整体较低,且抗病基因较单一,存在小麦条锈病在条件适宜时大面积流行的风险,必须进一步加强病害预警预报。     

Assessment of phenotypic diversity of Plasmopara viticola on Vitis genotypes with different resistance

The lack of characterized isolates of Plasmopara viticola is a very limiting issue in the management of downy mildew of grapevine. Although molecular studies have previously confirmed a high diversity of this pathogen, there are still no phenotypically characterized pathotype strains or races available which could be used to study the mechanisms of interaction with host genotypes of different resistance. A leaf disk inoculation technique was used to assess the variability of reactions of six different Vitis genotypes infected with single sporangial clones of five field isolates of P. viticola from different geographical origins. The virulence of thirty P. viticola clones was characterized on grapevine cultivars (Müller-Thurgau, Regent and Cabernet Cortis) and wild species (Vitis vinifera ssp. sylvestris, Vitis rupestris and Vitis riparia) with different susceptibility to downy mildew. Five categories ranging from full susceptibility with profuse and not clearly restricted sporulation (type A) to complete resistance with no sporulation or necrotic reaction (type E) were defined to evaluate the pathogen phenotype. A high variation of pathotypes was found amongst the samples from different field accessions and an unexpected variability was observed even between the cloned strains from the same field. This also accounted for the fungicide tolerance against the two most common fungicides, metalaxyl-M (Phenyl Amide group) and dimethomorph (Carboxylic Acid Amide group), where clones showing high sensitivity and high tolerance to the one or both fungicides were found within the same field. The virulence patterns found within clones of single field isolates supports previous reports that numerous genotypes may be involved in the infection of a single plant or even a single leaf. Moreover, the study provides a methodology to identify and select specific host–pathogen combination suitable for future studies in mechanisms of grapevine downy mildew interaction.     

黄淮麦区主推小麦品种对假禾谷镰刀菌所致茎基腐病的抗性

茎基腐病是我国小麦生产上一种新的土传病害,近年在黄淮麦区发生日益加重,成为影响小麦安全生产的新问题。为给该病的防治和抗病育种工作提供依据,本研究以国内新发现的小麦茎基腐病优势病原菌假禾谷镰刀菌(Fusarium pseudograminearum)Wz2-8A菌株为接种物,分别以国外抗病材料SUNCO和国内高度感病品种国麦301为抗性对照和感病对照,对黄淮麦区主推小麦品种进行了苗期盆栽接种和田间成株期接种抗性鉴定,并采用病情指数法进行了抗性评价。结果表明,供试品种在室内苗期及田间成株期均无免疫品种和高抗品种,其中室内苗期接种所有品种均表现感病或高度感病;田间病圃成株期抗性鉴定发现兰考198、许科718等10个黄淮麦区主推小麦品种表现为中抗,占供试品种总数的11.36%;焦麦266、郑麦004、郑麦0856等41个品种表现感病,占供试品种总数的46.59%;其余品种表现为高感,平均病情指数最高可达57.97,占供试品种总数的42.05%。本研究发现我国黄淮麦区主推小麦品种对茎基腐病优势病原菌假禾谷镰刀菌抗性整体较差,需要进一步加强抗病资源筛选,创制新的抗病材料,并充分利用中抗材料进行抗病育种。     

鲁西南地区小麦茎基腐病病原菌鉴定及其致病力分析

为明确山东小麦茎基腐病害主要致病菌组成及其致病力,于2016年在山东省聊城、德州、临沂市共7个地点采集了具有典型茎基腐症状的病株并对其主要致病菌进行了分离、鉴定和致病力分析。结果共分离到45株病原真菌,其中有22株为镰孢菌,分别属于假禾谷镰孢菌（Fusarium pseudograminearum）、禾谷镰孢菌（F.graminearum）和亚洲镰孢菌（F.asiaticum）,以假禾谷镰孢菌（F.pseudograminearum）分离频率最高,占所有镰孢菌株的68.18%;其余菌株属于链格孢菌（Alternaria spp.）。对22株镰孢菌进行小麦苗期致病力及重分离率测定发现,假禾谷镰孢菌（F.pseudograminearum）的致病力明显强于禾谷镰孢菌和亚洲镰孢菌,后两者的致病力相差不大;3种病原菌的重分离率均大于40%,病原菌测序鉴定结果与接种病原菌一致。     

花生对根结线虫病抗性温室快速鉴定方法

为了通过对花生抗线虫鉴定方法的比较,确定更加快速有效的抗性鉴定技术,作者于2002～2003年在佐治亚大学的Tifton试验站进行了温室盆栽试验.结果表明侵然期幼虫(2000～4000条/株)与虫卵(8000～16000粒/株)均可以用于花生抗线性鉴定的温室接种,但与使用虫卵接种相比,以侵染期幼虫作为接种体需要多花3～5d的时间收集幼虫;接种后14d,可以依据0～5级的虫瘿分级标准将供试的4份花生种质区分开来;接种后6～10周依据卵块数量或每克根中的虫卵数可以进一步确认花生的抗性水平.虫瘿级数、虫瘿数量、卵块数量及每克根中的卵量之间存在着极显著(P＜0.01)的正相关关系.根据研究结果提出了温室中花生抗线虫鉴定的程序方法以8000粒卵/株为适宜接种量,接种后14d依据0～5级的虫瘿分级标准进行初筛,对初筛入选的材料再在接种后6周根据卵块数量或卵量验证其抗性.     

Evaluation of sugarcane smut resistance in wild sugarcane (Saccharum spontaneum L.) accessions collected in Japan

ABSTRACT

Sugarcane smut, caused by Sporisorium scitamineum, is one of the most important sugarcane diseases in Japan. Wild sugarcane, Saccharum spontaneum, is known to be a key breeding material to obtain high-yielding clones. In this study, we sought to identify Japanese wild sugarcane accessions with high resistance to smut. Thirty wild sugarcanes and three sugarcane cultivars were tested by the pinprick method. The results of the inoculation tests aided in identifying wild sugarcanes with high resistance to smut disease, namely JW90, Iriomote8, and Iriomote15. After screening the germplasm, progeny distribution of smut resistance from the inoculation test and dry matter productivity in the smut disease-free field were compared. The highly resistant wild sugarcane accession had a much better impact on progeny distribution of smut resistance compared with the susceptible accession. No relationship was found between smut resistance and dry matter productivity in both populations.