结球甘蓝根肿菌鉴定和种质抗性评价

采集湖北省长阳县火烧坪乡根肿病重发区的病土和病根,通过病原菌形态和PCR鉴定,确定是芸薹根肿菌,然后利用欧洲ECD鉴别系统确定生理小种为ECD17/31/13,此病原菌致病力极强。采用田间苗期人工接种鉴定,与田间成株期自然诱发鉴定相结合,对88份甘蓝种质进行抗性评价和筛选,结果表明:苗期获得1份高抗,7份抗病,17份耐病材料;成株期获得4份高抗,4份抗病,15份耐病材料。2个时期88份材料群体抗性鉴定级别基本一致,93.18%材料成株期病指比苗期高。CR21在2个时期均为高抗,抗性最强,表现稳定;CR55在苗期发病最严重,病指达到76.19,成株期为74.10;CR54在成株期发病最严重,病指达到81.54,苗期为75.97,2个时期发病率均达到100%。根肿病菌的鉴定和致病力的确定,及甘蓝种质抗性评价为抗病品种选育和抗病机理的研究奠定基础。     

萝卜种质资源耐抽薹性鉴定评价

以来源于国内外的73份代表性萝卜种质为研究对象,以4℃春化处理种子21 d,田间鉴定评价萝卜种质的耐抽薹性。结果显示,田间生长136 d时,9份国外材料仍未显蕾,表现为极耐抽薹,其中来源于韩国(6份)和日本(1份)的大萝卜资源7份,来源于日本的黑萝卜和俄罗斯的樱桃萝卜各1份。采用7个指标对显蕾开花的64份萝卜种质进行系统评价分析表明,各指标的次数分布基本符合正态分布,蕾期薹高略向低值区域偏离。方差分析结果显示,7个指标在不同材料间的差异显著。相关性分析表明,显蕾期和开花期的相关性达到极显著水平,显蕾期和开花期均可作为评价萝卜抽薹早晚的指标。抽薹速度分别与花期薹高、薹高差、抽薹天数的相关性达到极显著水平,综合了这4个指标的描述特性,较好地反映了不同萝卜种质的抽薹能力。花期薹高与薹高差、抽薹速度的相关性极显著,可用该指标评价抽薹能力,简单易行。分别用主成分分析和隶属函数法评价64份抽薹开花萝卜种质的耐抽薹性,不同耐性种质均能被很好地区分开,其中筛选出的2份耐抽薹种质的评价结果一致,主成分聚类分出1份极不耐抽薹种质。     

菊花及其近缘种属植物耐涝评价体系建立及耐涝性鉴定

为发掘耐涝种质资源,建立了菊花近缘种属植物苗期耐涝性评价体系.根据盆栽淹水处理过程菊花近缘种属植物表型变化,将涝害指数划分为7级;采用叶色、叶形态、茎色、茎形态4个外观形态指标,并将其定量分级,制定等级得分标准及评价方案,然后以各指标得分的总和对耐涝性进行综合评价,建立评价体系.对57个菊花近缘种属植物进行了苗期耐涝性鉴定,结果表明,耐涝性鉴定时间以淹水6d为宜;菊花近缘种属植物对水涝较为敏感,大部分材料属于较不耐涝级,同种不同种源存在耐涝性差异;初步筛选出8份耐涝性强的菊花优异种质.     

辣椒种质资源抗青枯病的鉴定与评价

采用青枯菌FJC100301菌株对田间辣椒（Capsicum annuum）抗病品种76a和感病品种TW-1分别作了不同温度、不同接种量和不同接种方法的接种试验。结果表明,辣椒青枯病抗性的室内鉴定以接种温度28℃、浸根20 min和3×10^8cfu/mL接种浓度为宜;辣椒种质田间抗青枯病接种鉴定宜选择5月上旬进行,浸根20 min,接种浓度为3×10^8cfu/mL。采用田间抗性接种鉴定的方法,用青枯菌FJC100301菌株对106份辣椒材料进行了抗性鉴定。田间接种后每隔10 d统计病情指数,划分辣椒抗青枯病鉴定分级标准,获得了高抗材料14份、抗病材料8份、中抗材料23份、中感材料23份、感病材料20份、高感材料18份;采用离体叶片接种法对田间筛选得到的高抗和高感纯度较高品种进行抗性分析,结果与田间鉴定一致。     

茶树种质资源抗病性鉴定

１９８７～１９９５年开展了茶树种质资源抗病性鉴定研究．经田间和室内鉴定试验,从３４份资源材料中筛选出对茶轮斑病高抗材料１份,抗性材料１１份;从３０份资源材料中筛选出对茶苗根结线虫病高抗材料５份,抗性材料１３份．从而为抗病育种或推广生产提供了抗源材料,同时也为抗性机制及遗传规律研究提供了基础．     

马铃薯耐盐性离体鉴定方法的建立及52份种质资源耐盐性评价

为探究马铃薯种质资源耐盐性强弱,采用添加NaCl的MS培养基模拟盐胁迫的方法,研究了不同盐浓度对4份不同熟性耐盐代表材料的株高、总生物量、芽鲜质量和生根率的影响,确定耐盐筛选适宜浓度为100 mmol/L。利用该浓度胁迫52份马铃薯种质,采用隶属函数和聚类分析的方法进行耐盐性鉴定,综合评价得到极端耐盐材料为陇薯5号和LZ111,极端盐敏感材料为青薯9号、陇薯8号、中薯14号和04P48-3。本研究建立的马铃薯耐盐性离体鉴定方法和筛选获得的不同耐盐种质,将为耐盐育种及机理研究奠定技术和材料基础。     

茄子种质资源的耐冷性鉴定

采用低温胁迫下幼苗叶片冷害指数、种子活力指数、叶片电导百分率为指标,对34份不同类型的茄子种质资源进行耐冷性鉴定.结果表明,活力指数与冷害指数、电导百分率均呈极显著负相关,电导百分率与冷害指数呈极显著正相关.通过耐冷隶属函数值和聚类分析,初步筛选出11份耐冷性较强的材料.     

茄子种质资源的耐冷性鉴定

采用低温胁迫下幼苗叶片冷害指数、种子活力指数、叶片电导百分率为指标,对34份不同类型的茄子种质资源进行耐冷性鉴定。结果表明,活力指数与冷害指数、电导百分率均呈极显著负相关,电导百分率与冷害指数呈极显著正相关。通过耐冷隶属函数值和聚类分析,初步筛选出11份耐冷性较强的材料。     

小麦种质对麦长管蚜的抗性鉴定与评价

2002-2005年连续4年,选用蚜情指数法对小麦种质进行麦长管蚜田间自然感蚜抗性鉴定,从2000份小麦种质中筛选出不同抗性材料34份,占总鉴定材料的1.7%,其中高抗种质5份、抗性种质9份、中抗种质20份。利用苗期室内接虫法,对部分抗感小麦种质进行鉴定,结果表明,苗期的抗性表现与成株期基本一致。对杂交组合临远207(抗)×Witchita(感)的F1、F2的抗性遗传分析表明,临远207对麦长管蚜的抗性由1对显性单基因控制。     

黄麻种质芽期和苗期耐盐性的鉴定与评价

本研究以12份黄麻种质为材料,芽期采用萌发实验法、苗期采用营养液栽培法,进行耐盐性鉴定与评价.结果表明:芽期耐盐性鉴定及其耐盐等级划分可以相对盐害率为指标,而苗期则以平均盐害指数为指标.黄麻芽期耐盐性与苗期耐盐性之间存在极显著相关性(r=0.8432**,n=10);经筛选获得了3份高耐盐材料:9511、中黄麻1号、93繁-13,耐盐等级均为1级;1份盐敏感性材料:孟圆,芽期耐盐等级为5级,苗期耐盐等级为4级.     

Components Analysis of Race Non-Specific Resistance to Blast Disease of Rice Caused by Pyricularia oryzae

A group of 69 rice cultivars with diverse degrees of resistance to rice blast disease (at least in a qualitative sense) was chosen for a detailed study of some components of race non-specific resistance, i.e. relative disease efficiency, latent period, and sporulation capacity. Large differences amongst cultivars were found. The overlapping of the normal curves for the qualitative reaction and the components of race non-specific resistance point out the difficulties of rapid screening for blast resistance by simple observation in the field. One approach to overcome these difficulties could be to use component(s) analysis in the evaluation of rice germplasm to identify parents or progeny having the attributes of race non-specific resistance.     

Haplotype diversity and population structure in cultivated and wild barley evaluated for Fusarium head blight responses

Fusarium head blight (FHB) is a threat to barley (Hordeum vulgare L.) production in many parts of the world. A number of barley accessions with partial resistance have been reported and used in mapping experiments to identify quantitative trait loci (QTL) associated with FHB resistance. Here, we present a set of barley germplasm that exhibits FHB resistance identified through screening a global collection of 23,255 wild (Hordeum vulgare ssp. spontaneum) and cultivated (Hordeum vulgare ssp. vulgare) accessions. Seventy-eight accessions were classified as resistant or moderately resistant. The collection of FHB resistant accessions consists of 5, 27, 46 of winter, wild and spring barley, respectively. The population structure and genetic relationships of the germplasm were investigated with 1,727 Diversity Array Technology (DArT) markers. Multiple clustering analyses suggest the presence of four subpopulations. Within cultivated barley, substructure is largely centered on spike morphology and growth habit. Analysis of molecular variance indicated highly significant genetic variance among clusters and within clusters, suggesting that the FHB resistant sources have broad genetic diversity. The haplotype diversity was characterized with DArT markers associated with the four FHB QTLs on chromosome 2H bin8, 10 and 13 and 6H bin7. In general, the wild barley accessions had distinct haplotypes from those of cultivated barley. The haplotype of the resistant source Chevron was the most prevalent in all four QTL regions, followed by those of the resistant sources Fredrickson and CIho4196. These resistant QTL haplotypes were rare in the susceptible cultivars and accessions grown in the upper Midwest USA. Some two- and six-rowed accessions were identified with high FHB resistance, but contained distinct haplotypes at FHB QTLs from known resistance sources. These germplasm warrant further genetic studies and possible incorporation into barley breeding programs.     

The Sbm1 locus conferring resistance to Soil-borne cereal mosaic virus maps to a gene-rich region on 5DL in wheat.

A mosaic disease caused by Soil-borne cereal mosaic virus (SBCMV) is becoming increasingly important, particularly in winter wheat in Europe. As there are currently no effective cultural practices or practical environmentally friendly chemicals for disease control, host plant resistance is an important objective in breeding programs. However, development of resistant cultivars is slow owing to difficulties in germplasm screening for resistance. Therefore, there is a need to identify molecular markers linked to SBCMV-resistance gene(s), so that quick and accurate laboratory-based marker-assisted selection rather than prolonged field-based screens for resistance can be used in developing resistant cultivars. We previously demonstrated that resistance to SBCMV in Triticum aestivum 'Cadenza' is controlled by a single locus. In this work, we used AFLP and microsatellite technology to map this resistance locus, with the proposed name Sbm1, to the distal end of chromosome 5DL. Interestingly, several expressed disease-resistance gene analogues also map to this gene-rich region on 5DL. Closely linked (approximately 17 cM interval) markers, BARC110 and WMC765, RRES01 and BARC144, that flank Sbm1 will be very useful in breeding for selection of germplasm carrying Sbm1.     

高粱对丝黑穗病的抗性及遗传研究

1981—1985年在人工接种的条件下,对1239份高粱品种资源,进行了抗丝黑穗病性鉴定。与此同时,用17个抗性不同的品种系,按照不完全双列杂交设计,进行了高粱对丝黑穗病的抗性遗传研究。结果表明,高粱对丝黑穗病的抗性遗传方式因品种而异。有的品种系具数量性状遗传特点,有的则具有质量性状遗传特点。抗病性属数量性状遗传的品种系,其抗性主要是受加性基因控制。     

小麦赤霉病新抗源的发掘与抗性位点的检测分析

小麦赤霉病是由禾谷镰刀菌引起的世界性重要病害,发掘优异的抗性种质资源、培育抗病品种是持续防治赤霉病最经济且环境友好的措施。为发掘新的赤霉病抗源,本研究于2017—2021年在弥雾保湿大棚中,采用单花滴注法对642份小麦种质资源的赤霉病抗扩展性进行鉴定,同时利用已知抗赤霉病基因/位点Fhb1~Fhb7的分子标记对筛选出的抗性种质基因型进行分析。结果表明,不同年份间赤霉病病小穗率的相关性均达到极显著水平。筛选到3年及以上赤霉病抗性优于扬麦158的种质81份,主要来自长江中下游麦区,其中33份种质连续4年抗性优于扬麦158;筛选到3年及以上抗性与苏麦3号相当的种质9份,分别为望水白、Grandin、浩麦1号、剑子麦、魁小麦、农林26、软秆洋麦、苏麦2号和武农6号,其中剑子麦、软秆洋麦、苏麦2号和Grandin连续4年抗性与苏麦3号相当。对抗性种质携带的抗赤霉病基因/位点进行分析发现,浩麦1号、冀师7225-28、南农13Y110、石优17和武农6号不携带任何已知抗赤霉病基因/QTL,为小麦抗赤霉病研究和品种培育提供了新的种质资源和理论依据。     

Effects of Fusarium graminearum Metabolites on Wheat Tissue in Relation to Fusarium Head Blight Resistance

Fusarium head blight (FHB) of wheat is caused by Fusarium graminearum which produces many secondary metabolites including the trichothecene mycotoxins deoxynivalenol (vomitoxin) and 3-acetyldeoxynivalenol. Coleoptile tissue segements from 14 spring wheat cultivars were exposed to the F. graminearum metabolites deoxynivalenol, 3-acetyldeoxynivalenol, butenolide (all known mycotoxins), sambucinol, culmorin and dihydroxycalonectrin in a bioassay. The tissue of most cultivars was inhibited, at a concentration of 10^?6M by the trichothecenes tested and up to 10^?3M for the other compounds. Deoxynivalenol and 3-acetyldeoxynivalenol, which affect protein synthesis at the ribosome, are therefore potent phytotoxins in addition to being mycotoxins. The resistance or susceptibility of each cultivar to FHB was established in a field experiment. A comparison of the two sets of data indicated that resistant cultivars could tolerate much higher concentrations of the metabolites tested than susceptible cultivars. Some resistant material can tolerate 10 to 1000 times the concentration of the trichothecenes, compared with susceptible cultivars, with no effect on growth. The data suggest that it may be possible to screen germplasm rapidly for FHB resistance in vitro and a new type of resistance in wheat to this disease is proposed based on the apparent insensitivity to trichothecenes by resistant cultivars, additional to the three types of resistance described in the literature.     

Comparison of Acyrthosiphon pisum probing behaviors on different alfalfa cultivars

Acyrthosiphon pisum (Harris) is a major pest of alfalfa worldwide. Here, we evaluated the resistance of eight alfalfa cultivars to A. pisum to identify resistant cultivars. The Giga-8 DC-EPG technique was used to record differences in electrical waveform patterns of probing behavior to identify cultivars with higher resistance. The frequency and average duration of EPG waveforms significantly differed among the cultivars, with eight documented waveforms (np, C, pd, E1, E2, sE2, F, and G). The longer duration of np, C, F and E1 waveforms reflected stronger resistance, whereas longer sE2 waveforms reflected weaker resistance. The resistance-related waveforms, np and C, occurred most frequently with Sardi 7, the time of the first E waveforms were the latest, duration of G waveforms and F waveforms were the longest, the feeding waveforms E2 and sE2 were the shortest, the time of reaching phloem for feeding was the latest, with notable resistance in leaf epidermis, mesophyll and phloem. The number of C waveforms occurring with Gibraltar were the least, duration of np waveforms was short, feeding waveforms were long, time to reach the phloem for feeding was early, and the resistance was not pronounced in various tissues. After comprehensive evaluation, the resistance levels of 8 alfalfa cultivars were as follows: High resistance, Sardi 7; Resistance, Zhongcao No. 3, Derby, WL319HQ; Low resistance, Golden Empress, Algonquin, Zhaodong; Susceptible, Gibraltar. In conclusion, evaluation of cultivar resistance to aphids can provide baseline data for selecting and planting cultivars with high local resistance.     

结球甘蓝耐裂球研究进展

综述了国内外结球甘蓝裂球性状及鉴定方法的研究进展,从裂球的遗传因素、叶片解剖特征、生理生化特性等方面分析了结球甘蓝裂球发生的原因,并提出了防治裂球的栽培措施.     

DNA markers for Fusarium head blight resistance QTLs in two wheat populations

Genetic resistance to Fusarium head blight (FHB), caused by Fusarium graminearum, is necessary to reduce the wheat grain yield and quality losses caused by this disease. Development of resistant cultivars has been slowed by poorly adapted and incomplete resistance sources and confounding environmental effects that make screening of germplasm difficult. DNA markers for FHB resistance QTLs have been identified and may be used to speed the introgression of resistance genes into adapted germplasm. This study was conducted to identify and map additional DNA markers linked to genes controlling FHB resistance in two spring wheat recombinant inbred populations, both segregating for genes from the widely used resistance source ’Sumai 3’. The first population was from the cross of Sumai 3/Stoa in which we previously identified five resistance QTLs. The second population was from the cross of ND2603 (Sumai 3/Wheaton) (resistant)/ Butte 86 (moderately susceptible). Both populations were evaluated for reaction to inoculation with F. graminearum in two greenhouse experiments. A combination of 521 RFLP, AFLP, and SSR markers were mapped in the Sumai 3/Stoa population and all DNA markers associated with resistance were screened on the ND2603/Butte 86 population. Two new QTL on chromosomes 3AL and 6AS wer found in the ND2603/Butte 86 population, and AFLP and SSR markers were identified that explained a greater portion of the phenotypic variation compared to the previous RFLP markers. Both of the Sumai 3-derived QTL regions (on chromosomes 3BS, and 6BS) from the Sumai 3/Stoa population were associated with FHB resistance in the ND2603/Butte 86 population. Markers in the 3BS QTL region (Qfhs.ndsu-3BS) alone explain 41.6 and 24.8% of the resistance to FHB in the Sumai 3/Stoa and ND2603/Butte 86 populations, respectively. This region contains a major QTL for resistance to FHB and should be useful in marker-assisted selection. Received: 17 August 2000 / Accepted: 16 October 2000     

Screening for Barley yellow dwarf virus-Resistant Barley Genotypes by Assessment of Virus Content in Inoculated Seedlings

The content of Barley yellow dwarf virus (BYDV) in roots and leaves of barley seedling plants differing in their level of resistance was assessed by quantitative ELISA 1–42 days after inoculation with the strain of BYDV (PAV). High virus accumulation in roots and low concentration in leaves was characteristic of the period 9–15 days after inoculation. In leaves, the differences in virus content between resistant and susceptible genotypes became significant after 15 days and resistance to virus accumulation was better expressed 30–39 days after inoculation. Roots of resistant materials exhibited evident retardation of virus accumulation and the greatest difference in virus content between resistant and susceptible plants was detected 9 days after inoculation. By these criteria, the selected winter and spring barley cultivars and lines (in total 44 materials) fell in to five groups according to field reactions and the presence or absence of the Yd2 resistance gene. There were highly significant and positive relations between ELISA values and 5‐year field data on symptomatic reactions and grain‐yield reductions due to infection. Using the described method, resistant and moderately resistant genotypes (both Yd2 and non‐Yd2) were significantly differentiated from susceptible genotypes. The possible use of this method in screening for BYDV resistance is discussed.