Evaluation of the Ugandan sorghum accessions for grain mold and anthracnose resistance

Sorghum accessions from Uganda were evaluated for grain mold and anthracnose resistance during the 2005 and 2006 growing seasons at the Texas A&M University Research Farm, near College Station, TX. Accession PI534117 and SC719-11E exhibited the lowest grain mold severities of 2.4, whereas, accessions PI534117, PI534144, PI576337, PI297199, PI533833, and PI297210, with SC748-5 were highly resistant to anthracnose in both years. Accessions PI534117, PI297134, PI297156 exhibited low grain mold severities in 2006. Significant negative correlation was recorded between grain mold and percent germination and high temperature in both years. In 2006, daily precipitation recorded significant positive correlation with grain mold. The seed mycoflora was analyzed across sorghum lines and treatments. In 2005, Curvularia lunata and Fusarium thapsinum were the most frequently recovered fungal species with 31 and 21% incidence, respectively, followed by Alternaria spp. (19%) and F. semitectum (13%). In 2006, predominant colonizers were F. thapsinum (58%), followed by Alternaria and F. semitectum with 15 and 10, percent respectively, while C. lunata had a 6% incidence. In this study, PI534117 holds promise for multiple disease resistance, as it had the lowest disease severity of grain mold and was highly resistant to anthracnose in both years. It also has a high germination rate, a high seed weight, and its short stature is more advantageous for the new A-line conversion program.     

芒果种质对炭疽病的抗病性评价

采用离体叶片抗病性鉴定法对来自国内外的189份芒果种质进行了抗炭疽病抗性评价.结果表明:参试种质中未发现免疫种质,其中高抗种质9份、中抗种质55份、中感种质90份、感病种质34份和高感种质1份.对于这64份抗病种质,应在炭疽病流行年份继续开展田间抗病性评价工作,同时结合农艺性状评价,确定种质是否能在生产上推广或能否作为育种材料.试验结果为189份芒果种质抗炭疽病创新利用奠定了基础.     

小麦品种在西藏的抗条锈性变异监测分析

为了解不同小麦品种在西藏的抗锈性表现,于2009-2011年在西藏林芝西藏农牧学院实习农场,对来自全国小麦条锈病菌变异观察圃的46份已知抗性基因小麦品种、45份生产及后备品种和由西藏农牧学院保存的26份西藏小麦种质资源(包括生产品种、引进抗源品种及区试材料)进行了田间自然诱发抗条锈病鉴定。结果表明,在小麦条锈病菌变异观察圃中,46份已知基因品种中33份表现为抗病,3份表现为感病,10份抗性不稳定;45份生产及后备品种中20份表现为抗病,12份表现为感病,13份抗性不稳定;26份西藏种质中,22份表现为抗病,3份表现为感病,1份抗性不稳定。调查表明,大部分材料表现出较稳定的抗病性,但目前在西藏高原麦作区实际生产中应用却较少。为减轻小麦条锈病的发生危害,应进一步加强抗病品种的选育和推广。     

Characterization of Solanum chomatophilum resistance to 2 aphid potato pests, Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer)

The aphids Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) are responsible for yield reduction in potato (Solanum tuberosum) production by direct phloem feeding and by spreading viruses. Breeding resistant traits from Solanum chomatophilum into the potato germplasm provides alternative means to control aphid infestations. Integrated pest management strategy, using plant resistance, benefits from the characterization of the resistance and of its impact on aphid biology. Our objective was to characterize the resistance of S. chomatophilum by assessing the effects of accessions, plant parts on aphid performance, and by assessing the impact of the resistance factors on different aphid developmental stages and on alate morph production. Detailed aphid performance was obtained by measuring fecundity, survival, percentage of nymphs that reached adult moult, and population growth using whole plant and clip cage experimental designs. Accession and plant physiological age, but not aphid developmental stage, influenced all life-history parameters, except for alate morph production which was not induced on the resistant accessions. Plant part influence was independent of plant species and accession. Both experimental designs resulted in congruent resistance levels at the accession level for each of the two aphid species, supporting the use of any of them in S. chomatophilum resistance screening. PI243340 was resistant to both aphid species, while PI365324 and PI310990 were also resistant to M. euphorbiae and M. persicae, respectively.     

229份杧果种质对炭疽病抗性初步评价

炭疽病是杧果的重要病害,严重影响杧果的生长势以及杧果的产量和质量,选种抗病品种是有效的防治方法之一。采用室内离体叶片抗病性鉴定法,初步鉴定了在农业部儋州杧果种质资源圃中的229份杧果种质对炭疽病的抗病性。结果表明,在参试的种质中未发现免疫和高感种质,其中高抗种质13份、中抗种质36份、中感种质116份、感病种质64份,这些种质的初步评价,为进一步展开杧果抗病遗传规律及分子育种研究打下了基础。     

中国橡胶树主栽品系和部分种质对尖孢炭疽病的室内抗性评价

橡胶炭疽病是橡胶树重要的叶部病害之一,已成为影响天然橡胶产量的主要限制因素。我国对橡胶树炭疽病病原物鉴定结果一直为胶孢炭疽(Colletotrichum gloeosporioides）,直到2008年在云南首次发现危害我国橡胶树的炭疽菌有尖孢炭疽(Colletotrichum acutatum）。针对我国对于尖孢炭疽病研究甚少的现状,研究组对从广东、云南、海南分离得到的橡胶树尖孢炭疽病菌菌株进行了致病性测定,并用菌丝体接种鉴定方法对国内橡胶树主要种质和品系进行抗尖孢炭疽病评价。结果发现,在供试的91个种质中,有抗病种质6个(占总数的6.6 %)、轻感病种质57个(占总数的62.6 %)、易感病种质28个(占总数的29.8 %);在18个国内主推品种的抗病性评价中发现抗病品种4个(占总数的22 %)、轻感病品种11个(占总数的63 %)、易感病品种1个(占总数的5.6 %)。SAS统计分析结果表明,不同种质或品种对尖孢炭疽病的抗性水平存在明显差异;在α=0.05水平上,抗病种质或品种与轻感病种质或品种及易感病种质或品种间的差异达到显著水平。     

国内外优异高粱种质资源的综合评价

对“八五”、“九五”期间收集到的820份国内外高粱品种资源进行农艺性状、抗病虫、抗逆性筛选鉴定及综合评价。试验表明，有一批矮秆、大穗、大粒、抗或多抗性的资源，可作为育种的基础材料，供资源创新、改良现有品种的品质、抗性等选择利用。     

Evaluation of Rice Germplasm for Resistance to the Small Brown Planthopper （Laodelphax striatellus） and Analysis of Resistance Mechanism

One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper (SBPH) (Laodelphax striatellus Fallén) by the modified seedbox screening test. Twenty-five rice accessions with different levels of resistance to SBPH were detected, accounting for 18.1% of the total accessions, which included 2 highly resistant, 9 resistant and 14 moderately resistant varieties. Compared with indica rice, japonica rice was more susceptible to SBPH. Antixenosis test, antibiosis test and correlation analysis were performed to elucidate the resistance mechanism. The resistant check Rathu Heenati (RHT), highly resistant varieties Mudgo and Kasalath, and resistant variety IR36 expressed strong antixenosis and antibiosis against SBPH, indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties. Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis. Dular, ASD7 and Milyang 23 had relatively strong antixenosis and antibiosis, indicating the two resistance mechanisms were significant in these three varieties. The resistant DV85 expressed relatively high level of antixenosis but low antibiosis, whereas Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH, suggesting tolerance in these three varieties. Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311. Antixenosis was the main resistance type in V20A. Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance. The above accessions with strong antibiosis or antixenosis were the ideal materials for the resistance breeding.     

亚麻品种资源对枯萎病的抗性评价 —06

利用亚麻枯萎病病圃,对508份国内外亚麻品种资源进行了抗枯萎病的鉴定和评价,按照参试品种较统 一感病对照发病率的降低率,把抗枯萎病程度划分为高抗(HR) 、中抗(MR) 、低抗(LR) 、低感(LS) 、中感(MS)和高 感(HS)共6个级别。各个级别的品种资源数分别为45、38、64、92、112 和157;分别占试验资源总数的8. 9%、 7. 5%、12. 5%、18. 1%、22. 1%和30. 9%。高、中抗资源共计16. 4%。筛选出的高抗和中抗枯萎病资源中有41份 属于首次报道,其中包括13份国外引进品种、7份国内地方品种和21份国内育成品种,一些重点抗源已成功地应 用于亚麻抗枯萎病育种实践。     

10份香蕉种质对枯萎病的抗性评价(简报)

采用苗期、田间抗性评价方法,对引进的10份香蕉种质(台蕉1号、台蕉3号、台蕉4号、台蕉7号、GCTCV-106、GCTCV-119、GCTCV-247、FHIA-03、FHIA-18、FHIA-25)进行枯萎病4号小种的抗性评价.结果表明:10份香蕉种质中,GCTCV-119、FHIA-18、FHIA-25抗性为高抗;台蕉1号、台蕉4号、GCTCV-247、FHIA-03抗性为抗:台蕉3号、台蕉7号、GCTCV-106抗性为中抗.     

Interspecific crossability and cytogenetic analysis of sexual progenies of Mexican wild diploid 1EBN speciesSolanum pinnatisectum andS. cardiophyllum

Mexican wild diploid species,Solanum pinnatisectum (S. pnt) (2n=2x=24, 1EBN: endosperm balance number) is a useful germplasm source of late blight and Colorado potato beetle (CPB) resistance in potato improvement. However, it is very difficult to cross this species with other 1EBNSolanum species. Sexual hybrids among three accessions ofS. pnt and two accessions ofS. cardiophyllum (S. cph) (2n=2x=24, 1EBN) were studied. There were large differences in the cross-compatibility among the genotypes and accessions from these two 2x-1EBN species. Interspecific incompatibility existed in the crosses betweenS. pnt andS. cph, in whichS. cph functioned only as the male parent. The crosses with accessions PI 275236 ofS. pnt produced 35 hybrids following the conventional propagation procedures. Seven hybrids were obtained with theS. pnt accession PI 275233 with the aid of embryo rescue, while hybridization involving accession PI 253214 resulted in no fruit. The cytogenetic analysis indicated that all of the hybrids derived from crosses of accession PI 275233 ofS. pnt withS. cph had 2n = 24 chromosomes and were pollen fertile. Crosses involving accession PI 275236 ofS. pnt produced both 2x (2n=24) and 3x (2n=36) hybrids. Meiotic analysis at metaphase I of pollen mother cells (PMCs) showed a fairly high rate of chromosome pairing that averaged between 10.10 and 11.10 bivalents per cell in most of the 2x hybrids, indicatingS. pnt andS. cph have the similar genome. A high frequency of trivalents and quadrivalents were observed in 3x hybrids derived fromS. pnt 2 ×S. cph 1, indicating homology exists among these chromosomes. These results suggest that specific gene(s) and not either differences between genomes or EBN controlled interspecific crossability and embryo development. The disease and insect tests on the 2x and 3x hybrids revealed that all have high levels of resistance to both late blight and CPB. Thus it could appear that selection of genotypes is a key for successful interspecific hybridization when using Mexican wild diploid species as a source of economic important traits.     

橡胶树种质资源对白粉病和炭疽病的田间抗病性评价

白粉病和炭疽病是我国橡胶树的主要病害,严重影响胶乳产量,给天然橡胶产业带来了很大的经济损失。挖掘培育抗病性种质资源是最经济、有效的防治措施。本研究通过分析2018、2019、2021年白粉病和炭疽病田间自然发病数据,评价192份橡胶树种质的抗病性,旨在为橡胶树抗病育种提供数据支撑。结果表明,白粉病2019年发病严重,种质群体的病情指数平均值达34.37,最大值为94.07;2018年和2021年则发病较轻,病情指数平均值分别为10.68和9.70。炭疽病2021年发病严重,种质群体的病情指数平均值达29.12,最大值为65.31;2018年和2019年则发病较轻,病情指数平均值分别为18.64和18.15。利用重病年数据鉴定出白粉病高抗品种24个、中抗品种9个,炭疽病抗性品种35个。这33份和35份抗性种质在3 a内对白粉病和炭疽病均达到抗性水平,分别占供试种质的22%和19%。利用隶属函数和聚类分析对这些候选抗病种质进行抗性水平排序,对白粉病抗性排名前10的种质隶属函数平均值为0.86~1.00,标准偏差值为0.003~0.073。在白粉病抗性聚类树遗传距离2.5处,排序第1的‘湛试5025’单独聚为一类,排序前2~6位的种质聚为一类,与其他类区分明显;对炭疽病抗性排名前10的种质隶属函数平均值为0.83~0.90,标准偏差值为0.020~0.102。在炭疽病抗性聚类树遗传距离2.5处,排序前5的种质单独聚集为一类,与其他类区分明显。初步筛选出抗白粉病优异的种质‘湛试5025’‘湛试12-3’‘湛试5005’‘天任31-45’‘湛试5026’,筛选出抗炭疽病优异的种质‘湛试477-6’‘湛试366-2’‘湛试485-114’‘湛试41-3’‘RO42’。本研究建立的抗性鉴定、隶属函数和聚类分析相结合的分析方法为橡胶树种质抗病性综合评价提供了重要的技术参考。     

小麦抗纹枯病种质资源的鉴定与评价

为了筛选小麦纹枯病稳定抗源,在对国内外小麦种质资源初选的基础上,采用人工病麦粒接种法对114份小麦品种纹枯病抗性进行了连续3年的鉴定.结果表明,在参试品种中未发现免疫或高抗纹枯病材料,大部分为中抗材料,共筛选出包括Niavt 14、剑子麦、新麦26在内的37份稳定抗和中抗纹枯病种质.在这些抗病材料中,13份为国内改良品种,7份为国内地方品种,17份为国外引进品种.其中国内改良品种农艺性状较好,可直接用于抗病育种,国内地方品种和国外品种农艺性状较差,需要进一步改良后用于抗病育种.     

Evaluation of Rice Germplasm for Resistance to the Small Brown Planthopper(Laodelphax striatellus)and Analysis of Resistance Mechanism

One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper(SBPH)resistance to SBPH were detected,accounting for 18.1%of the total accessions,which included 2 highly resistant,9 resistant and 14 moderately resistant varieties.Compared with indica rice,japonica rice was more susceptible to SBPH.Antixenosis test,antibiosis test and correlation analysis were performed to elucidate the resistance mechanism.The resistant check Rathu Heenati(RHT),highly resistant varieties Mudgo and Kasalath,and resistant variety IR36 expressed strong antixenosis and antibiosis against SBPH,indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties.Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis.Dular,ASD7 and Milyang 23 had relatively strong antixenosis and antibiosis,indicating the two resistance mechanisms were significant in these three varieties.The resistant DV85 expressed relatively high level of antixenosis but low antibiosis,whereas Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH,suggesting tolerance in these three varieties.Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311.Antixenosis was the main resistance type in V20A.Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance.The above accessions with strong antibiosis or antixenosis were the ideal materials for the resistance breeding.     

栽培大豆种质资源对大豆菌核病的抗性评价

采用离体叶柄接种法鉴定了200份栽培大豆高世代品系对大豆菌核病菌株Jia30和Jian29的抗感反应.结果表明:在所有的参鉴材料中没有发现免疫类型,但各品系间抗性有一定的差异.供试200个品系中既表现抗Jia30菌株义表现抗Jian29菌株的材料占供试材料的2%;抗Jia30菌株的材料占3%;抗Jian29菌株的材料占5%,根据抗性资源筛选结果,这些抗性材料可合理地用于大豆生产,并为大豆抗病育种亲本选择和利用品种布局进行大豆菌核病生态控制提供了依据.     

芝麻抗茎点枯病及枯萎病种质的评价

1997－1998年,对“八五”期间收集的芝麻种质资源初鉴获得的高抗茎点枯病和高抗枯萎病种质共85份及4个育种单位提供的8个新品系,在芝麻主产区三个生态试验点（病圃）进行了鉴定评价,均与当地优良品种进行比较,评价出抗性稳定、相对病情指数＜15％的抗茎点枯病种质34份、抗枯萎病种质38份,其中兼抗两种病害的27份,并明确了不同基因型抗源在不同生态系统中的抗性表现及利用价值、对抗、感品种酯酶同工酶分析表明,在A区检测出感病品种的相似性和抗、感品种间的带型差异。     

Evaluation of wildSolanum species for resistance to the US-8 genotype ofPhytophthora infestans utilizing a fine-screening technique

Greenhouse assays were carried out to characterizeSolanum accessions previously reported to be late blight resistant and to identify individuals within the accessions with high levels of resistance to late blight. Foliage of wildSolanum species accessions or hybrid cultivated potato x wild species (diploid or tetraploid) from Mexico, Russia, or South America was inoculated withPhytophthora infestans (US-8) and was scored for severity of foliar symptoms at 7 and 14 days after inoculation (DAI). Mexican accessions (S. brachycarpum,S. pinnatisectum,S. guerreroense, andS.fendleri) were significantly more resistant (1.1% infection at 14 DAI) than either Russian (59.1% infection at 14 DAI) or South American (53.4% infection at 14 DAI) accessions. Moreover, the genotypes within the Mexican accessions tended to be more uniformly resistant whereas genotypes within the Russian and South American accessions tended to segregate for resistance. The more resistant genotypes of Russian and South American accessions (176/546) were retested, and 56 genotypes were identified as having potential for use in potato breeding programs for resistance to late blight. Fifty percent of the selected genotypes were fromS. microdontum accessions PI498124, PI595510, and PI595511. The potential of these species for incorporation into breeding programs for late blight resistance is discussed.     

山东主栽花生品种对疮痂病的抗性鉴定

为明确山东省主栽花生品种对疮痂病的抗性及疮痂病对花生产量的影响，2018-2019年在山东省莱西市对36个主栽品种进行了抗疮痂病鉴定，鉴定通过人工接种分别在田间和温室大棚内进行，并分析了病害对产量影响。结果表明，供试品种有高感品种8份，占鉴定品种总数的22.22%；感病品种4份，占鉴定品种总数的11.11%；中抗品种2份，占鉴定品种总数的5.56%；抗病品种11份，占鉴定品种总数的30.56%；高抗品种11份，占鉴定品种总数的30.56%。花生疮痂病病情与产量损失率呈指数关系，病情指数越高，花生产量损失率越大。     

大豆品种对立枯丝核菌的抗性研究!

运用种子腐烂率测试法对208份大豆材料进行测试,研究了根腐病原菌中立枯丝核菌对大豆的致病性,并对抗大豆立枯丝核菌抗源材料进行筛选。结果表明:立枯丝核菌是大豆根腐病病原菌中致病性较强的一种,大部分品种对立枯丝核菌高度感病,高感品种(系)153个,占参试材料的73.55%;高抗品种(系)21个,占参试品种(系)的10.1%,其中有7个来自国外;中抗品种(系)34个,占参试品种(系)的16.35%,其中12个中抗材料为创新改良的稳定品系。     

芝麻优良种质资源的深化鉴定与综合评价

“八五”期间，在不同生态区的１４个试验点，连续三年对“七五”筛选出的各类优良资源２２５份进行了深化鉴定与综合评价，评选出稳定优异资源５５份。其中具有稳定高耐渍、高抗茎点枯病和高抗枯萎病的多抗性资源１份（ＷＺＭ１５２３缅甸黑芝麻）；某一优良性状稳定且产量较对照种平均增产１０％以上，可直接在生产上推广利用的优异资源９份（高耐渍高产资源３份；ＺＺＭ１４０８、ＺＺＭ２８７１、ＺＺＭ２８７５，高抗枯萎病高产资源４份：ＺＺＭ０２４３、ＺＺＭ０５７４、ＺＺＭ０８６６、ＷＺＭ３１１３，高油分高产资源２份：ＺＺＭ２５４１、ＺＺＭ２５４５）；具有某一优良性状但产量较低，可间接作育种亲本材料利用的４５份。