棉花枯黄萎病及其抗性鉴定技术

棉花枯黄萎病是我国最主要的棉花病害,种植抗病品种是有效的防治方法。抗病鉴定是棉花抗病育种的关键技术之一。人工病圃鉴定是棉花抗病鉴定的主要方法,相对抗性指数(IR)或相对抗病效果(ER)最适合作为抗病鉴定指标,根据棉花的抗病程度可将棉花的抗病水平分为免疫、高抗、抗病、耐病和感病5级。     

棉花抗枯、黄萎病品种苗期耐低钾种质筛选研究

本研究采用蛭石栽培和营养液浇灌的方法,确立棉花品种苗期耐低钾筛选指标,利用这些指标,评价我国88个抗枯、黄萎病棉花品种资源苗期耐低钾能力,并筛选钾素利用率高的优异种质。结果表明,株高、地上部干物重、地下部干物重、总干物重、钾利用率、叶绿素含量在不同钾浓度处理和不同品种之间均存在显著差异,可以作为棉花苗期耐低钾能力的评价指标,而叶面积在不同品种和不同钾浓度处理之间不存在差异。利用筛选出的指标对88个品种进行耐低钾评价,结果供试品种主要被分为耐低钾基因型、耐低钾中间类型和非耐低钾基因型3类,分别包括21个、58个和6个品种。     

基因工程改良棉花纤维品质研究进展

棉花作为世界上重要的经济作物,其纤维品质是衡量棉花品质的重要指标.优良的纤维品质是国内外棉花育种的主要目标之一,面临常规育种改良品质的瓶颈,通过转基因技术改良棉花纤维品质是棉花遗传育种致力研究的重要领域.介绍棉纤维发育相关分子机理研究、棉纤维品质改良功能基因的发掘以及利用基因工程技术改良棉花纤维品质的最新进展,并对今后的研究进行展望.     

棉花抗枯、黄萎病品种苗期耐低钾种质筛选研究

本研究采用蛭石栽培和营养液浇灌的方法,确立棉花品种苗期耐低钾筛选指标,利用这些指标,评价我国88个抗枯、黄萎病棉花品种资源苗期耐低钾能力,并筛选钾素利用率高的优异种质。结果表明,株高、地上部干物重、地下部干物重、总干物重、钾利用率、叶绿素含量在不同钾浓度处理和不同品种之间均存在显著差异,可以作为棉花苗期耐低钾能力的评价指标,而叶面积在不同品种和不同钾浓度处理之间不存在差异。利用筛选出的指标对88个品种进行耐低钾评价,结果供试品种主要被分为耐低钾基因型、耐低钾中间类型和非耐低钾基因型三类,分别包括21个、58个和6个品种。     

棉花纤维品质分子改良研究进展

棉花纤维是重要的天然纤维和纺织工业原料。目前国内外棉花育种家除了利用常规技术外,还大规模开展了棉花纤维品质分子改良的育种研究。综述了利用基因工程手段进行棉花纤维品质改良的分子育种相关研究进展。     

棉花抗枯、黄萎病品种系谱组成对其产量性状的影响

对我国引进和育成的52个抗枯、黄萎病品种的系谱及其对产量性状的影响进行分析,结果表明岱字棉与斯字棉血统在52个品种中占有较大的比例,其次是福字棉,而其他品种的血统较少。根据几个主要种质在不同品种中所占的比例进行聚类分析,可将52个品种分为4类。系谱组成不同对品种产量性状具有一定的影响,尤其对单铃重和子指影响较大。含有较大比例岱字棉血统的第一类品种单铃重明显高于含有较小比例岱字棉血统和部分斯字棉血统的第二类品种;第一类品种的子指也明显高于第二类品种和含有较大比例斯字棉血统的第四类品种。     

我国首获转基因抗黄萎病棉花新株系

我国科学家在世界上首次获得转基因抗黄萎病棉花新株系。中国农业大学植物病理系齐俊生博士课题组,在导师李怀方教授的指导下,经过6年的努力,从“海岛棉”中分离、克隆出有自主知识产权的抗黄萎病基因“At7”,并导入到“陆地棉”,从而培育出高抗黄萎病的新体系。     

长江流域棉区棉花新品种抗病虫性研究

2003年,对长江流域棉区15份新材料进行了抗红铃虫鉴定,结果有8份材料高抗红铃虫,占鉴定材料的53.33%;4份材料抗红铃虫,占26.67%;3份材料中抗红铃虫,占20.00%.对55份新材料进行抗枯萎病鉴定,结果有27份材料抗枯萎病,占鉴定材料的49.09%;26份材料耐枯萎病,占47.27%;2份感枯萎病,占3.64%.对59份材料进行抗黄萎病鉴定,结果有8份材料抗黄萎病,占鉴定材料的13.56%;43份材料耐黄萎病,占72.88%;8份材料感黄萎病,占13.56%.     

Genetic analysis of Verticillium wilt resistance in a backcross inbred line population and a meta-analysis of quantitative trait loci for disease resistance in cotton

Background

Verticillium wilt (VW) and Fusarium wilt (FW), caused by the soil-borne fungi Verticillium dahliae and Fusarium oxysporum f. sp. vasinfectum, respectively, are two most destructive diseases in cotton production worldwide. Root-knot nematodes (Meloidogyne incognita, RKN) and reniform nematodes (Rotylenchulus reniformis, RN) cause the highest yield loss in the U.S. Planting disease resistant cultivars is the most cost effective control method. Numerous studies have reported mapping of quantitative trait loci (QTLs) for disease resistance in cotton; however, very few reliable QTLs were identified for use in genomic research and breeding.

Results

This study first performed a 4-year replicated test of a backcross inbred line (BIL) population for VW resistance, and 10 resistance QTLs were mapped based on a 2895 cM linkage map with 392 SSR markers. The 10 VW QTLs were then placed to a consensus linkage map with other 182 VW QTLs, 75 RKN QTLs, 27 FW QTLs, and 7 RN QTLs reported from 32 publications. A meta-analysis of QTLs identified 28 QTL clusters including 13, 8 and 3 QTL hotspots for resistance to VW, RKN and FW, respectively. The number of QTLs and QTL clusters on chromosomes especially in the A-subgenome was significantly correlated with the number of nucleotide-binding site (NBS) genes, and the distribution of QTLs between homeologous A- and D- subgenome chromosomes was also significantly correlated.

Conclusions

Ten VW resistance QTL identified in a 4-year replicated study have added useful information to the understanding of the genetic basis of VW resistance in cotton. Twenty-eight disease resistance QTL clusters and 24 hotspots identified from a total of 306 QTLs and linked SSR markers provide important information for marker-assisted selection and high resolution mapping of resistance QTLs and genes. The non-overlapping of most resistance QTL hotspots for different diseases indicates that their resistances are controlled by different genes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1682-2) contains supplementary material, which is available to authorized users.     

Genetic analysis of resistances to races 1 and 2 of Fusarium oxysporum f. sp. lycopersici from the wild tomato Lycopersicon pennellii

Summary Resistance to race 3 of Fusarium wilt in the wild tomato Lycopersicon pennellii (LA 716) was previously found to be controlled by one major locus, I-3, tightly linked to Got-2 on chromosome 7. This accession was also found to carry resistance to races 1 and 2; a genetic analysis of these resistances is reported in this paper. This analysis proceeded in two steps. First, allelism tests demonstrated that race 1 and 2 resistances carried by L. pennellii were not allelic to the I and I-2 genes originally incorporated into L. esculentum from L. pimpinellifolium. Second, an interspecific backcross with L. pennellii (BC₁) was used to determine the mode of inheritance of these new resistances and their chromosomal location by segregation and linkage analysis. BC₁ responses to each of the races were determined using progeny tests (BC₁S₁). BC₁S₁ plants were inoculated with race 1 or 2 and evaluated after 1 month using a visual disease rating system; mean disease ratings were calculated for each BC₁ individual for each race based on the progeny scores. A bimodal frequency distribution of the BC₁ mean disease ratings was observed for both races, indicating that one major locus controlled resistance in each case. Statistical comparisons of the mean disease ratings of homozygous versus heterozygous individuals at each of 17 segregating enzyme loci were used to map the resistances to races 1 and 2. Tight linkage was detected between the enzyme locus Got-2 and resistances to both races, as was previously reported for the I-3 locus. Therefore, the Got-2 locus can be used as a selectable marker for resistances to all three races. The relationship of these resistances is discussed in the paper. In addition, as previously reported for race 3, significance was also detected for the chromosome segment marked by Aps-2 on chromosome 8 for both races. Currently many cultivars carry I and I-2 resistances to races 1 and 2. Incorporation of the LA 716 resistances to these two races into cultivars may reduce the likelihood of new race development.Florida Agricultural Experiment Station, Journal Series No. R-00205     

海岛棉品种抗黄萎病基因SSR标记的验证及克隆

以陆地棉与海岛棉杂交组合中棉所8号×Pima90-53 F2群体的100个单株和邯208×Pima90-53 F2的131个单株为材料,在条件可控的培养室鉴定抗病性,进行海岛棉黄萎病抗性基因连锁SSR标记(BNL3255-208)分析,进一步检验该标记的应用价值,并对该标记进行克隆、测序。结果表明,2个组合的F2群体中抗病、感病植株比例经x2c适合性测验均符合3∶1分离比例;中棉所8号×Pima90-53 F2的79个抗病单株中有70株检测出BNL3255-208标记,抗病单株中有该标记的百分率为88.6%,邯208×Pima90-53 F2的100个抗病单株中有85株检测出BNL3255-208标记,抗病单株中有该标记的百分率为85.0%。通过回收BNL3255-208片段,并进行克隆和测序,表明该标记是一条长211bp、含10次TG重复的片段,该标记为辅助选育抗病品种奠定了基础。     

棉花黄萎病及其抗病育种的研究

就棉花黄萎病菌的致病机理、棉花的抗黄萎病机制、抗黄萎病的遗传方式以及抗黄萎病棉花育种等方面的研究进行了综述。     

大丽轮枝菌毒素的分离、提纯及生物测定

试验用Czapek's培养液培养大丽轮枝菌(Verticillium dahliae Kleb.)不同致病力类型的5个菌株的培养滤液,经浓缩、离心和透析制成的粗毒素,再经DEAE-纤维素柱层析得到初提毒素,最后通过琼脂糖凝胶过滤层析获得纯毒素样品。生物活性测定表明初提毒素的最低生物活性浓度为5.0—5.5μg/ml。纯毒素的最低生物活性浓度为4.0—4.5μg/ml。配制相同浓度的不同致病力类型菌株的毒素液,它们的培养滤液、粗毒素或纯毒素对棉苗的致萎能力相同。