外来玉米种质的抗病和抗逆性选育

为改善国内玉米种质遗传基础狭窄、缺少优良抗性种质资源的状况,在500余份外引玉米材料中,鉴定筛选优良的抗病、抗逆基因,通过与国内骨干系杂交或组建抗病、抗逆群体,鉴别筛选含抗病、抗逆基因的材料回交纯合,再通过配合力测定,最终选育出新的优良自交系用于国内杂交种的选育,由此鉴定筛选出高抗锈病的材料25份、高抗大斑病10份、高抗穗腐病2份、高抗小斑病1份、高抗灰斑病2份、特早熟材料5份等,其中有现已标记定位出的不同抗大斑单基因的玉米材料8份,现已标记定位出的不同抗锈病基因的玉米材料25份,经进一步的遗传改良,获得超过35份抗病、抗逆自交系,利用新的抗逆自交系选育出特早熟玉米新品种植9831。     

玉米种质资源对大斑病的抗病性鉴定

“七五”期间,在南京、昆明、太原和丹东等地对我国2028份玉米材料进行大斑病抗性鉴定的结果,高抗材料3份,抗病55份,中抗169份,感病1801份。自交系的中抗以上种质占的比例高于农家品种中的比例。     

陕 A 群、陕 B 群玉米自交系抗病性鉴定及产量评价

为了解陕 A 群、陕 B 群玉米自交系的抗病性和丰产性,研究大斑病、茎腐病和穗腐病在陕西关中西部的发生规律,探讨抗病性与产量性状的相关性,以 42 份玉米自交系为试验材料,通过人工接种和病圃鉴定的方法,分类鉴选抗病、高产的玉米自交系。结果表明：陕 A 群、陕 B 群玉米自交系整体抗性水平较高,对大斑病的平均抗性为中抗,对茎腐病的平均抗性为抗,对穗腐病的平均抗性为中抗。A09、A12、A13、A14、B01、B07、B09、B14 兼抗以上 3 种病害,可作为抗性资源重点利用;A06、A17、A16、A05、A04、A12、A14、B11、B15、B16、B07 单穗粒重较高,可作为高产资源加以利用;A12、A14 和B07 既有较好的抗性,单穗粒重水平也较高,值得重点关注。该结果可为玉米抗病、高产育种及抗病机制研究提供理论参考和种质资源。     

玉米自交系对大斑病菌的抗性鉴定及抗性来源分析

玉米大斑病是一种严重影响玉米产量的病害,在全国各地多有发生。通过筛选抗病玉米自交系,选育优良抗病品种可以有效防止大斑病的发生。试验于2017-2018年,用田间人工接种大斑病混合菌的方法,对185份玉米种质进行了玉米大斑病抗性鉴定与评价,筛选出高抗自交系16份,其中自选系7份,并对玉米自选系抗病性来源进行分析,发现Y6和J1577等品系抗病性强且可以稳定遗传。     

26份玉米材料灰斑病抗性鉴定及分子标记检测

为了解不同来源玉米自交系灰斑病抗性位点分布,探索利用分子标记筛选玉米灰斑病抗性种质,本研究以26份玉米骨干自交系为材料,按照国家标准(NY/T 1248.11-2016)进行人工接种鉴定,选用6个与抗灰斑病主效QTL(或基因)紧密连锁的分子标记进行分子检测.结果表明,经接种鉴定,抗性级别表现为中抗及以上的有15份,其中...     

主要杂种优势群玉米矮花叶病抗性评价与比较分析

采用摩擦接种的方法对81份材料的玉米矮花叶病抗性进行了鉴定,从中筛选出了20份高抗材料,25份抗病材料。抗性鉴定结合杂种优势群的划分结果表明,大部分的抗病材料来自P群和唐四平头类群,而瑞德群、兰卡斯特类群和自330类群的大部分自交系均高感玉米矮花叶病,不同杂种优势类群间的抗性有极显著的差异,据此将中国主要的五大优势群自交系粗略地划分为三大抗性类型,一是高抗类型,仅包括P群的自交系;二是中抗类群,仅包括唐四平头群的自交系;三是感病类群,包括瑞德、兰卡斯特和自330三大类群的自交系,在此基础上对玉米矮花抗性杂优模式进行了探讨。     

玉米种质资源抗腐霉茎腐病鉴定

腐霉茎腐病(Pythium stalk rot)是玉米生产上的重要病害。2013—2016年, 对1213份玉米种质资源进行了抗肿囊腐霉(Pythium inflatum)茎腐病的鉴定与评价。在1213份玉米种质中, 鉴定出高抗肿囊腐霉茎腐病的材料207份, 占鉴定总数的17.1%, 主要来自中国的内蒙古、河北、山西及美国等地。抗性材料159份, 占鉴定材料数的13.1%, 主要由源自中国的内蒙古、云南、山西和美国等地的种质构成。由此可见, 玉米种质中存在较为丰富的抗腐霉茎腐病资源, 且抗性水平与地理来源有关。自交系和农家种中对肿囊腐霉茎腐病表现高抗的种质分别占鉴定种质总数的18.7%和10.6%, 表明自交系中高抗肿囊腐霉茎腐病资源较农家种更为丰富。     

玉米矮花叶病毒抗性资源鉴定的研究

利用人工接毒方法对 70份玉米种质资源进行了两年玉米矮花叶病毒B株系的抗性鉴定。依据病情指数 ( % )将抗病程度分为高抗、抗、中抗及感病 4个等级。试验筛选出高抗自交系 4份、高抗单交种 3个、抗病毒自交系 10份、抗病单交种 3个 ;中抗自交系 6份、中抗群体 3个。讨论了这些种质资源在我国抗玉米矮花叶病遗传及育种研究上的应用价值     

大豆种质资源对灰斑病抗性评价和广谱抗源鉴定

对中国南北方大豆品种和新品系进行抗灰斑病鉴定,旨在为抗病育种提供优良抗源和挖掘新的抗病基因。大豆生育期进入R3~R4阶段对593份大豆材料进行人工接种灰斑病菌。结果表明：北方高抗材料比例明显高于南方材料;在高抗材料中品种所占的比例明显高于品系和资源,抗病材料中资源所占的比例高于品种和品系;不同区域品种、品系均有抗灰斑病的材料;高抗和抗病品种为92份,高抗和抗病品系为57份。对200份材料多生理小种鉴定结果表明有55份材料抗5~10个生理小种,其中抗5~7个生理小种的材料为48份。南北方大豆资源中均有抗灰斑病的材料,北方高抗材料比例明显高于南方材料,抗病材料南北方持平。     

玉米抗灰斑病基因的分子标记

玉米灰斑病是我国玉米生产中的重要病害,培育和种植抗病品种是防治此病的有效途径.1年内在3个灰斑病重发区选取64份我国常用玉米自交系进行了抗灰斑病鉴定,分别筛选出高抗、抗病和中抗自交系2份、15份和12份.采用集团混合分组分析法,分别以10个抗病和10个感病玉米自交系基因组DNA构建抗病基因池和感病基因池.从100对AFLP引物组合中筛选出54对在抗感基因池间呈多态性的引物,进一步在组建抗池和感池的20份自交系之间检测到8个多态性片段.通过片段的回收、克隆和测序,将其中的P51M38-100扩增片段转化为SCAR标记(SCAR-100).利用SCAR-100标记分析64份玉米自交系的基因型,结合田间抗病和感病表型进行相关分析,卡方测验表明SCAR-100标记与抗灰斑病显著相关.采用Mo17×黄早四群体(190个F2单株)和X178×B73群体(181个F8家系),结合已构建的SSR和AFLP标记连锁图谱,均将SCAR-100标记定位于第3染色体上,分别位于SSR标记umc1399-bnlg1754和umc1320-bnlg1754之间.开发抗病基因的分子标记可为分子标记辅助育种提供基础.     

玉米抗甘蔗花叶病毒的遗传分析

选用2个抗病自交系（黄早四、Pa405）与2个感病自交系（掖107、Mo17）配制4套杂交组合,通过对双亲、F1、F2及回交群体苗期植株叶片危害度和成株期植株病级的调查分析,研究了玉米抗甘蔗花叶病毒的遗传规律。结果表明,苗期和成株期玉米杂交组合F1的抗感程度与遗传背景有关,抗性遗传不符合加性-显性模型。掖107组配的两个组     

玉米拟轮枝镰孢菌穗腐病抗性基因的挖掘

玉米穗腐病是一种严重危害玉米生产的真菌性病害,而目前在世界范围内玉米育种上应用的大多数自交系缺少对穗腐病的抗性。玉米穗腐病抗性位点的挖掘和抗病基因的克隆,对玉米穗腐病的遗传改良至关重要。本研究旨在通过转录组测序和全基因组关联分析的方法进行玉米拟轮枝镰孢菌穗腐病抗性位点的挖掘并初步确定候选基因。抗病自交系法A和感病自交系掖81162的转录组测序结果表明,人工接种拟轮枝镰孢菌后7d两个自交系的差异表达基因有10,761个。通过全基因组关联分析共检测到5个与穗腐病抗性显著相关的SNP,这些SNP分布在1号和9号染色体上。通过比对B73 RefGen_v3并注释,发现SNP位点附近涉及的基因包括酰基激活酶1过氧化物酶体、蛋白磷酸酶2C 48、镁转运蛋白、受体蛋白激酶CRINKLY4和锌指CCCH域蛋白19。将在转录组测序中获得差异表达基因和全基因组选择中关联到的基因进行比对,发现全基因组关联分析中关联到的锌指CCCH域蛋白19同时也是转录组测序中获得的差异表达基因,表明锌指CCCH域蛋白19可能与玉米拟轮枝镰孢菌穗腐病的抗性相关。本研究结果不仅能为抗病基因的克隆和玉米的抗病分子育种提供一定的理论依据和重要的遗传资源,而且能为玉米和病原菌的相互作用机理的解析奠定基础。     

Resistance to Sclerotinia sclerotiorum of 'high oleic' sunflower inbred lines

Cultivation of sunflower (Helianthus annuus L.) is strongly affected by Sclerotinia sclerotiorum. To identify new sources of genetic diversity for sunflower breeding 25 sunflower inbred lines were analysed using eight Amplified Fragment Length Polymorphism (AFLP) primer combinations and their genetic similarities (GS) were estimated. Data were used to develop a Unweighted Pair Group Method using Arithmetic Averages (UPGMA) dendrogram. GS values of 0.58‐0.98 were observed but with no separate groupings dependant on oil quality. The inbred lines were screened for their reaction to inoculation with Sclerotinia sclerotiorum (Lib.) de Bary. Sunflower heads were artificially inoculated with S. sclerotiorum in three environments. Head infection was monitored after 1 week (lesion length) and 2 weeks (head rot). The F5 generation of a cross between a resistant (SWS‐B‐04) and a susceptible inbred line (SWS‐B‐01) was also tested for sclerotinia reaction across three environments. Significant differences in sclerotinia resistance, moderate heritabilities and a high correlation between the two assessments were observed. Inbred lines with a high level of resistance could be identified. These lines can be used for further breeding to improve sunflower sclerotinia resistance and to develop superior new hybrids.     

抗粗缩病玉米种质和新组合鉴定分析初报

为鉴定和筛选出适于黄淮海地区种植的抗粗缩病的玉米新品种,采用田间自然感病鉴定的方法,对295份玉米自交系和10个用其组配的高产杂交组合进行粗缩病抗性鉴定。鉴定出高抗玉米自交系12份、抗性玉米自交系32份、中抗玉米自交系69份、感病玉米自交系71份和高感玉米自交系115份以及3个抗粗缩病的玉米杂交组合。其中,12份高抗玉米自交系可以直接用于抗粗缩病玉米新品种的选育。在选育抗粗缩病玉米新品种的初期,必须确保玉米杂交组合的母本和父本均达到中抗以上水平,或者其父本或母本之一必须为高抗粗缩病的自交系。     

Identification of RAPD and SCAR markers linked to northern leaf blight resistance in waxy corn (Zea mays var. ceratina)

Exserohilum turcicum causes northern corn leaf blight (NCLB), an important disease occurring in maize producing areas throughout the world. Currently, the development of cultivars resistant to E. turcicum seems to be the most efficient method to control NCLB damage. Marker-assisted selection (MAS) enables breeders to improve selection efficiency. The objective of this work was to identify random amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) markers associated with NCLB resistance. Bulked segregant analysis (BSA) was used to search for RAPD markers linked to NCLB resistance genes, using F₂ segregating population obtained by crossing a susceptible inbred ‘209W’ line with a resistant inbred ‘241W’ line. Two hundred and twenty-two decamer primers were screened to identify four RAPD markers: OPA07₅₂₁, OPA16₄₅₇, OPB09₅₂₀, and OPE20₅₃₆ linked to NCLB resistance phenotype. These markers were converted into dominant SCAR markers: SCA07₄₉₆, SCA16₄₂₀, SCB09₄₆₄, and SCE20₄₂₉, respectively. The RAPD and SCAR markers were developed successfully to identify NCLB resistant genotypes in segregating progenies carrying NCLB resistant traits. Thus, the markers identified in this study should be applicable for MAS for the NCLB resistance in waxy corn breeding programs.     

枇杷种质资源SSR标记指纹图谱的构建

为构建枇杷种质资源指纹图谱,采用SSR标记技术对国家枇杷种质资源圃33份品种进行多态性分析,从近缘属苹果属和梨属的51对SSR引物中筛选出能够稳定扩增,多态性好的7对引物,Hi01d05F、Hi12f04F、CH02B10F、Hi03a03、Hi03e04、Hi04a05和Hi02c07来构建指纹图谱。结果表明,应用这7对引物可100%区别33个枇杷种质。这种SSR标记构建的枇杷种质资源指纹图谱对于品种分类及鉴定具有重要的应用价值。     

水稻抗咪唑啉酮类除草剂基因ALS功能标记的开发与应用

选育和利用抗除草剂水稻品种具有重要的生产实践意义。通过筛选水稻资源, 发现了抗除草剂材料金粳818, 其ALS基因编码区第1880位碱基存在一个由G到A的碱基变异, 导致丝氨酸突变为天冬酰胺, 从而具有除草剂抗性。本研究基于该位点的碱基变异, 设计了11条等位基因特异PCR (allelic-specific PCR, AS-PCR)引物, 经过优化筛选, 获得两个引物组合F1N (S1/S9)和F1M (S1/S10), 将该标记命名为AS-ALS。利用F₂群体及其亲本和杂交种, 结合AS-ALS标记检测和除草剂抗性分析, 结果表明感除草剂ALS-G等位基因型只能被F1N引物对有效扩增, 抗除草剂ALS-A等位基因型只能被F1M引物对有效扩增, 而杂合基因型能同时被两对引物F1N和F1M扩增, ALS-A纯合或杂合等位基因型都表现抗除草剂, ALS-G纯合基因型表现感除草剂。因此本研究开发的标记能有效区分除草剂抗性基因的3种基因型, 基因型与表型完全对应。该标记用于回交育种, 可以选择ALS-A杂合基因型单株, 剔除ALS-G纯合等位基因型, 在自交的F₂保留ALS-A纯合基因型单株, 连续自交, 能快速获得除草剂抗性稳定的水稻材料。该除草剂抗性基因的功能标记还可用于咪唑啉酮类除草剂抗性资源筛选。     

Genes for resistance to northern corn leaf blight in diverse maize populations

Turcicum or northern corn leaf blight (NCLB) incited by the ascomycete Setosphaeria turcica, anamorph Exserohilum turcicum, is a ubiquitous foliar disease of maize. Diverse sources of qualitative and quantitative resistance are available but qualitative resistances (Ht genes) are often unstable. In the tropics especially, they are either overcome by new virulent races or they suffer from climatically sensitive expression. Quantitative resistance is expressed independently of the physical environment and has never succumbed to S. turcica pathotypes in the field. This review emphasizes the identification and mapping of genes related to quantitative NCLB resistance. We deal with the consistency of the genomic positions of quantitative trait loci (QTL) controlling resistance across different maize populations, and with the clustering of genes for resistance to S. turcica and other fungal pathogens or insect pests in the maize genome. Implications from these findings for further genomic research and resistance breeding are drawn. Incubation period (IP) and area under the disease progress curve (AUDPC), based on multiple disease ratings, are important component traits of quantitative NCLB resistance. They are generally tightly correlated (r_p? 0.8) and highly heritable (h²? 0.75). QTL for resistance to NCLB (IP and AUDPC) were identified and characterized in three mapping populations (A, B, C). Population A, a set of 121‐150 F₃ families of the cross B52×mo17, represented US Corn Belt germplasm with a moderate level of resistance. It was field‐tested in Iowa, USA, and Kenya, and genotyped at 112 restriction fragment length polymorphism (RFLP) loci. Population B consisted of 194‐256 F₃ families of the cross Lo951×CML202, the first parent being a Corn‐Belt‐derived European inbred line and the second parent being a highly resistant tropical African inbred line. The population was also tested in Kenya and genotyped with 110 RFLP markers. Population C was derived from a cross between two early‐maturing European inbred lines, D32 and D145, both having a moderate level of resistance. A total of 220 F₃ families were tested in Switzerland and characterized with 87 RFLP and seven SSR markers. In each of the three studies, 12‐13 QTL were detected by composite interval mapping at a signifcance threshold of LOD=2.5. The phenotypic and the genotypic variance were explained to an extent of 50‐70% and 60‐80%, respectively. Gene action was additive to partly dominant, as in previous generation means and combining ability analyses with other genetic material. In each population, gene effects of the QTL were of similar magnitude and no putative major genes were discovered. QTL for AUDPC were located on chromosomes 1 to 9. All three populations carried QTL in identical genomic regions on chromosomes 3 (bin 3.06/07), 5 (bin 3.06/07) and 8 (bin 8.05/06). The major genes Ht2 and Htn1 were also mapped to bins 8.05 and 8.06, suggesting the presence of a cluster of closely linked major and minor genes. The chromosomal bins 3.05, 5.04 and 8.05, or adjacent intervals, were further associated with QTL and major genes for resistance to eight other fungal diseases and insect pests of maize. Bins 1.05/07 and 9.05 were found to carry population‐specifc genes for resistance to S. turcica and other organisms. Several disease lesion mimic mutations, resistance gene analogues and genes encoding pathogenesis‐related proteins were mapped to regions harbouring NCLB resistance QTL.