首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到16条相似文献,搜索用时 15 毫秒
1.
Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development.A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism(SNP)markers.The association panel was evaluated for reactions to three Bgt inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15.Linkage disequilibrum(LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb, and population structure analysis revealed seven subgroups in the panel.Association analysis using a mixed linear model(MLM) identified three loci for powdery mildew resistance on chromosome 2 B, designated QPm.stars-2BL1,QPm.stars-2BL2, and QPm.stars-2BL3.To evaluate the efficacy of GWAS in gene discovery,QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI420646 × OK1059060-126135-3.Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an interval where QPm.stars-2BL2 was located, lending credence to the GWAS results.QPm.stars-2BL1 and QPm.stars-2BL3, which were associated with four SNPs located at 457.7–461.7 Mb and two SNPs located at 696.6–715.9 Mb in the Chinese Spring reference IWGSC RefSeq v1.0, respectively, are likely novel loci for powdery mildew resistance and can be used in wheat breeding to improve powdery mildew resistance.  相似文献   

2.
中性洗涤纤维(NDF)是衡量青贮玉米纤维质量重要指标之一.以341份玉米自交系为材料,于2018年在沈阳和通辽种植并收获,对其秸秆NDF含量测定.利用全基因组重测序获得高质量的6 276 612个SNPs用于全基因组关联分析,结果表明,在所有染色体上共检测到69个显著SNPs位点(P<1.0x10-6),在显著水平P<...  相似文献   

3.
对分离自云南昆明感病稗草\[Echinochloa crus galli (L.) Beauv.\]上的病原真菌麦根腐平脐蠕孢(Bipolaris sorokiniana)和薏苡平脐蠕孢(Bipolaris coicis)开展了防治稗草潜力的评价。结果显示,B.sorokiniana和B.coicis两菌株培养5 d的发酵原液对稗草根长和芽长均有很高的抑制作用,根长最高抑制率分别为99.59%和95.78%, 芽长最高抑制率分别为91.14%和82.13%。两菌株对稗草离体叶片致病性的室内试验表明,菌丝体悬浮液处理5 d后稗草叶片病情指数最高可达100%。两菌株对稗草植株防效的温室试验表明, 菌丝体悬浮液处理稗草7 d后植株下部叶片出现萎蔫症状、脱落及死亡,处理21 d后稗草最高死亡率达到82.67%和80.00%。菌株对作物的安全性试验表明,麦根腐平脐蠕孢对作物的安全性显著高于薏苡平脐蠕孢。作为生防潜力菌株,麦根腐平脐蠕孢具有更大的应用潜力。  相似文献   

4.
In the last decade, association mapping (AM) has become a well-established method to detect genes and quantitative trait loci (QTLs) associated with agronomically important traits. The identification of a large number of single nucleotide polymorphisms (SNPs) from genome sequencing and concurrent development of high-throughput genotyping platforms has led to AM being widely used for a range of crops. These technologies have been used in rice (Oryza sativa) to explore the abundant diversity and there is enormous potential to identify novel QTLs for traits of interest. Due to the availability of cost-effective high-throughput SNP genotyping methods and rapid developments in rice genomics, it is inevitable that these AM approaches will become more popular in the future, especially in the context of genome-wide association studies (GWASs). In this paper, we review the fundamental concepts, critical considerations and limitations of AM focusing on rice, and reiterate the importance of accurate phenotypic data. We also include a section about connecting GWAS to molecular breeding, covering practical consideration for breeders, which is required to use GWAS results in actual rice molecular breeding programs and which has not received adequate attention in the scientific literature.  相似文献   

5.
小麦黑胚病病因复杂,链格孢(Alternaria alternata)、麦根腐平脐蠕孢(Bipolaris Sorokiniana)、层出镰刀菌(Fusarium proliferatum)等多种真菌是引起小麦黑胚病的主要病原。有限的研究报告显示,小麦对黑胚病的抗性具有数量性状特征,QTL定位研究尚处于初级阶段。目前报道的小麦抗黑胚病QTLs位于1D、2A、2B、2D、3D、4A、5A、7A等多条染色体上。小麦第2部分同源群携带了较多抗病QTLs,与这些QTLs连锁的分子标记有gwm319(2B)、gwm341(3DS)和wmc048(4AS)等,但是还没有见到这些标记在抗小麦黑胚病新品种培育中应用的报道。综上所述,针对目前小麦黑胚病抗性遗传研究中缺乏准确的抗性鉴定方法和病原不清导致的QTL定位结果不可靠的问题,应在明确病原菌的情况下,采取可靠的接菌鉴定方法进行QTL定位研究并开发分子标记,以期辅助抗黑胚病株系的选择。  相似文献   

6.
Stagonospora nodorum blotch (SNB), caused by Phaeosphaeria nodorum, is one of the most devastating foliar diseases on wheat (Triticum aestivum L.) in the northern Great Plains of North America. This study was conducted, under controlled environmental conditions, to elucidate the genetics and map the resistance to SNB caused by spore inoculum and culture filtrate of P. nodorum isolate Sn2000. A hard red spring wheat population was developed from a cross between the susceptible cultivar Steele-ND and the resistant line ND 735 for this study. Two-leaf seedlings of the parents, F1 and F2 generations, and F2:6 recombinant-inbred lines (RILs) were inoculated with spore suspensions while independent two week old seedlings of segregating generations were infiltrated with culture filtrate. Disease reaction was assessed 8 days after inoculation based on a lesion-type scale while plants were evaluated for culture filtrate response four days after infiltration for the presence or absence of necrosis. Genetic analysis revealed that a single recessive gene, Tsn1, in ND 735 confers resistance to both spore suspension and culture filtrate of P. nodorum isolate Sn2000. Mapping analysis using Diversity Arrays Technology (DArT) and simple sequence repeat (SSR) markers indicates the gene, Tsn1, is located on the long arm of chromosome 5B and is flanked by the DArt markers wPt-8285 and wPt-3049 at a distance of 7.0 cM and 2.9 cM, respectively. This gene also controls resistance to tan spot caused by Pyrenophora tritici-repentis race 2. Results of this study reveal that wheat-P. nodorum interaction follows the toxin model of gene-for-gene hypothesis. Additionally, the finding of single gene control in the line ND 735 for both tan spot and SNB enhances the utility of the line ND 735 in wheat breeding program as a source of multiple disease resistance.  相似文献   

7.
花生种质资源对黄曲霉菌侵染和产毒的抗性鉴定   总被引:4,自引:0,他引:4  
对不同种子成分的花生种质资源对黄曲霉菌侵染和产毒的抗性进行了鉴定,结果表明,高含油量、高蛋白质含量和高油酸含量资源对黄曲霉菌侵染和产毒的抗性较差.通过对抗黄曲霉侵染和产毒能力不同的花生种质资源的种子成分的分析表明,高抗黄曲霉菌侵染和产毒资源的亚油酸含量较高.相关分析表明,不同花生品种对黄曲霉菌的侵染抗性与种子大小和油酸含量呈显著负相关,与出仁率和亚油酸含量呈显著正相关;不同花生品种对黄曲霉菌产毒的抗性与含油量呈显著负相关.通过鉴定和筛选,发掘出2份优质抗病资源.  相似文献   

8.
Modulation of physiological and biochemical defensive responses against downy mildew (DM) of pearl millet induced by raw cow milk (RCM) and five amino acids is reported in this paper. In vitro conditions, none of the inducer treatments showed inhibitory action on DM pathogen. Significant enhancement of seed germination and seedling vigor was observed in RCM and amino acids treated seeds. Under greenhouse conditions, significant protection against DM was provided by l-phenylalanine (68.6%), l-isoleucine (66.5%) and l-proline (55.7%) treatments. Among the RCM treatments, the 10% dilution proved to be the best by offering disease protection of 35%. Spatio-temporal time gap studies indicated that seed treatment with l-phenylalanine increased disease resistance four days after inoculation. Seed treatments with RCM and amino acids also enhanced the vegetative and reproductive growth parameters of pearl millet when compared to the control. A similar trend in protection against DM was evident in the field trials. At the biochemical level, defense related enzymes such as phenylalanine ammonia lyase (PAL), peroxidase (POX) and β-1,3-glucanase showed an increased activity in RCM and amino acids treated seedlings than in sterile distilled water control seedlings. The highest PAL activity was recorded in RCM (10 and 20%) whereas in case of amino acids, the highest activity was observed in l-proline and l-phenylalanine treatments. The highest activity of β-1,3-glucanase was recorded in RCM (20%) and l-phenylalanine.  相似文献   

9.
The ‘within-season’ module of the Weed Manager decision support system (DSS) predicts the effect of twelve UK arable weeds on winter wheat yields and profitability. The model and decision algorithm that underpin the DSS are described and their performance discussed. The model comprises: (i) seedling germination and emergence, (ii) early growth, (iii) phenological development, (iv) herbicide and cultivation effects and (v) crop yield loss. Crop and weed emergence are predicted from the timing and method of cultivation, species biology, and the weather. Wheat and weeds compete for resources, and yield losses are predicted from their relative leaf area at canopy closure. Herbicides and cultural control methods reduce weed green area index, improving crop yield. A decision algorithm identifies economically successful weed management strategies based on model output. The output of the Weed Manager model and decision algorithm was extensively validated by experts, who confirmed the predicted responses to herbicide application were sufficiently accurate for practical use. Limited independent data were also used in the validation. The development of the module required integrating novel and existing approaches for simulating weed seedling establishment, plant development and decision algorithm design. Combining these within Weed Manager created a framework suitable for commercial use.  相似文献   

10.
Gene pyramiding (assembling multiple desirable genes into a single genotype) via conventional methods to combat Asian rust resistance in soybean (Glycine max (L.) Merrill) and developing soybean varieties with durable resistance to this disease continues to be a challenge. Therefore, our objectives were to pyramid four Asian rust (caused by Phakopsora pachyrhizi) resistance (Rpp) genes, viz., Rpp1, Rpp2, Rpp3, and Rpp4 from their respective donors, PI200492 (Komata), PI230971, PI462312 (Ankur), and PI459025 (Bing Nan). Two single crosses (PI200492 × PI230971; PI462312 × PI459025) and a double-cross [(PI200492 × PI230971) × (PI462312 × PI459025)] were made for present study. The scoring of parents and crosses was done according to a 0–9 grading scale, where 0 = 0% disease intensity (absolutely resistant), 1 = 1% disease intensity (highly resistant), 3 = 1.1–10% disease intensity (moderately resistant), 5 = 10.1–25% disease intensity (moderately susceptible), 7 = 25.1–50% disease intensity (susceptible), and 9 = more than 50% disease intensity (highly susceptible). Out of four parents used, Rpp1 gene-donor plant introduction (PI)200492 (Komata) was immune to rust, with a disease grade of 0.92. Rpp2 and Rpp4 gene donors, PI230971 and [PI459025 (Bing Nan)], had reddish-brown (RB) lesions. Rpp3 gene-donor PI462312 (Ankur) showed a few, highly localized patches of tan lesions; however, it was not as susceptible as the susceptible check JS335. In cross-A (PI200492 × PI230971), all the F1s were rust resistant, whereas in the F2, 93.9% (845 plants) were either immune (11.0%, 99 plants) showing no infection or had RB lesions (82.9%, 746 plants) with resistant reaction and the remainder 6.1% (55 plants) had susceptible reaction. In cross-B (PI462312 × PI459025), 80.8% (63 plants) of the F1 had RB lesions and resistant reaction, whereas 19.2% (15 plants) had susceptible reaction. In its F2 population, 24.2% (217 plants) were susceptible. In cross-C [(PI200492 × PI230971) × (PI462312 × PI459025)], i.e., double-cross hybrid (DCH), 85.5% (77 plants) were either immune or had RB lesions, whereas the rest of the plants 14.5% (13 plants) showed susceptible reaction. Based on parental survey, four simple sequence repeat primers were short-listed for amplification of individual rust-resistance gene-specific markers in ten plants of each cross, viz., Satt191-210bp (Rpp1 gene), Sat_361-245bp (Rpp2 gene), Satt263-195bp (Rpp3 gene), and Rpp4TM-128bp (Rpp4 gene). In the single-cross hybrid (SCH)-A (PI200492 × PI230971), six plants had both Rpp1 and Rpp2 genes, whereas in another SCH-B (PI462312 × PI459025), seven plants had both Rpp3 and Rpp4 genes. In DCH [(PI200492 × PI230971) × (PI462312 × PI459025)], a single plant had all four Rpp genes, five plants had two Rpp genes, whereas a single susceptible plant had only Rpp3 gene. The homozygous rust-resistant segregants from these crosses can be used for improving rust resistance of otherwise adapted, high-yielding soybean genotypes.  相似文献   

11.
T. Bjor 《Potato Research》1987,30(3):517-524
Summary For laboratory screening for resistance to gangrene andFusarium dry rot, the ‘scrape and paint’ method was compared to a ‘prick and paint’ method. In the latter method the potatoes were wounded before inoculation by rolling them over a group of nail points. The disease scores increased when the length of the nail points was increased from 2 to 6 mm, but the scores were lower than for scraped potatoes. For the 10 cultivars used, the results for the pricked and the scraped potatoes correlated equally well with the results from a ‘field inoculation’ method. The two laboratory methods discriminated equally well between resistant and susceptible cultivars. However, pricking is much less laborious than scraping. In routine tests with the ‘prick and paint’ method, differences between cultivars were highly significant over three years for resistance to gangrene but less significant forFusarium dry rot.
Zusammenfassung Für die Laborprüfung auf Resistenz gegenPhoma-Faule (Phoma exigua var.foveata) undFusarium-Trockenf?ule (Fusarium solani var.coeruleum) wurde die ‘scrape and paint’-Methode von Wiersema (1977a) mit einer ‘prick and paint’-Methode verglichen, wobei Kartoffeln vor Inokulation durch Rollen über eine Gruppe von Nagelspitzen, 1 cm auseinander und von einer h?lzernen Basis aufw?rtsweisend, besch?digt wurden. Für beide Krankheiten stieg der Krankheitsindex an, wenn die L?nge der Nagelspitzen von 2 auf 4 und 6 mm anstieg, war im Ganzen jedoch niedriger als bei geschürften Kartoffeln (Tabellen 2 und 4). Für die zehn für jeden Erreger in den Versuchen verwendeten Sorten korrelierten die Ergebnisse bei ‘prick’ (Rollen über Nagelspitzen) und ‘scrape’ (Schürfen) gleichermassen mit einem vermutlich besser zu verwirklichendem Feld-Inokulationstest (Bjor, 1980), dessen Ergebnisse in Tabelle 1 dargestellt sind. Die Unterscheidung von Sorten unterschiedlicher Resistenz war mindestens so deutlich beim ‘prick’ — wie beim ‘scrape’-Test, wie die F-Werte für Sorten in der Varianzanalyse zeigen (Tabellen 2 und 4). Darüberhinaus ist die ‘prick’-Methode betr?chtlich weniger arbeitsaufwendig als die ‘scrape’-Methode. Die ‘prick and paint’-Methode mit 4 mm-Nagelspitzen ergab Unterschiede zwischen 14 Standard-Sorten in Routinetests aus drei verschiedenen Jahren beiPhoma-F?ule, aber nicht so gut beiFusarium-Trockenf?ule (Tabelle 6). Die Korrelation zwischen den Ergebnissen nach der ‘prick and paint’-Methode und dem Feld-Inokulationstest bei den 14 Sorten warr=0,86 undr=0,71 beiPhoma-bzw.Fusarium-F?ule. Allerdings war die Variation innerhalb der Sorten bei Resistenz gegenPhoma-F?ule betr?chtlich gr?sser als die bei Resistenz gegenFusarium-Trockenf?ule.

Résumé Le criblage au laboratoire pour la résistance à la gangrène (Phoma exigua var.foveata) et à la pourriture sèche fusarienne (Fusarium solani var.coeruleum) est réalisé selon deux méthodes. La méthode du ‘grattage et du badigeonnage’ est comparée à celle de la ‘piq?re et du badigeonnage’ où les pommes de terre sont blessées avant l'inoculation en les faisant passer sur un groupe de 10 clous distants de 1 cm, orientés vers le haut et fixés sur un support de bois. Pour les deux maladies, la note de maladie augmente quand la longueur de la pointe des clous passe de 2 à 4 et 6 mm, mais les tubercules blessés par piq?res sont moins malades que ceux ayant subi des égratignures (tableaux 2 et 4). Pour les 10 cultivars inclus dans les expériences pour chacune des maladies, les résultats des tubercules blessés par chacune des 2 méthodes sont également corrélés avec ceux d'un test ‘inoculation au champ’, plus s?r (Bjor, 1980) figurant au tableau 1. Le classement des cultivars de différents niveau de résistance est aussi clair à partir des tubercules blessés par piq?re que ceux blessés par grattage comme le montre la valeur du F pour les cultivars, des analyses de variance (tableaux 2 et 4). De plus, la méthode des piq?res est beaucoup moins fastidieuse que la méthode par égratignures. La méthode des piq?res avec des pointes de clous de 4 mm reproduit les différences entre 14 cultivars de référence inclus dans des tests de routine depuis 3 ans pour la gangrène, mais de fa?on moins nette pour la fusariose (tableau 6). La corrélation entre les résultats obtenus avec la méthode des piq?res et le test ‘d'inoculation au champ’ pour les 14 cultivars estr=0,86 etr=0,71, respectivement pour la gangrène et la fusariose. En outre, la variabilité des cultivars pour la résistance à la gangrène est considérablement plus grande que celle vis-à-vis de la fusariose (Figure 1).
  相似文献   

12.
Thymic epithelial cells (TECs) account for the most abundant and dominant stromal component of the thymus, where T cells mature. Oxidative- or cytotoxic-stress associated injury in TECs, a significant and common problem in many clinical settings, may cause a compromised thymopoietic capacity of TECs, resulting in clinically significant immune deficiency disorders or impairment in the adaptive immune response in the body. The present study demonstrated that fish collagen peptides (FCP) increase cell viability, reduce intracellular levels of reactive oxygen species (ROS), and impede apoptosis by repressing the expression of Bax and Bad and the release of cytochrome c, and by upregulating the expression of Bcl-2 and Bcl-xL in cisplatin-treated TECs. These inhibitory effects of FCP on TEC damage occur via the suppression of ROS generation and MAPK (p38 MAPK, JNK, and ERK) activity. Taken together, our data suggest that FCP can be used as a promising protective agent against cytotoxic insults- or ROS-mediated TEC injury. Furthermore, our findings provide new insights into a therapeutic approach for the future application of FCP in the prevention and treatment of various types of oxidative- or cytotoxic stress-related cell injury in TECs as well as age-related or acute thymus involution.  相似文献   

13.
We report the effect of the introduction of a fungal glutamate dehydrogenase gene (gdhA) into forage rice (cv. Momiroman) by analyzing the transgenic rice plants in terms of growth, source function, and nitrogen contents. NADP (H)-dependent glutamate dehydrogenase activities in the gdhA-transgenic lines were markedly higher than those in non-transgenic control plants. Plant growth analysis at the seedling stage revealed that the leaf area and shoot and root dry weights of the high gdhA-expressors were higher than those of control plants under both high (high N) and low nitrogen (low N) conditions. These results suggested that the source ability was enhanced by the gdhA introduction. This was supported by the fact that the net photosynthesis rate at the heading stage was also higher in transgenic than in control leaves. Furthermore, under both high and low N conditions, the nitrogen contents in the shoots and roots, at seedling and grain-harvest stages, were significantly higher in high gdhA-expressors than in control plants, indicating that nitrogen uptake was higher in transgenic than in control plants. At the harvest stage, the high gdhA-expressors exhibited greater panicle and spikelet numbers per plant compared with control plants, resulting in higher grain weight, under the high N conditions. In addition, gdhA expression in forage rice significantly enhanced their tolerance to salt stress compared to control plants. The present study showed that the introduction of a fungal gdhA into forage rice could lead to higher source ability, better growth and higher grain weight by enhancing nitrogen uptake efficiency.  相似文献   

14.
Starch is a crucial component in wheat endosperm and plays an important role in processing quality. Endosperm of matured wheat grains contains two distinct starch granules (SG), referred to as larger A- and smaller B-granules. In the present study, 166 Chinese bread wheat cultivars planted in four environments were characterized for variation in SG size. A genome-wide association study (GWAS) using the 90 K SNP assay identified 23 loci for percentage volumes of A- and B-granules, and 25 loci for the ratio of A-/B-granules volumes, distributing on 15 chromosomes. Fifteen MTAs were associated with both the percentage volumes of A-, B-granules and the ratio of A-/B-granules volumes. MTAs IWB34623 and IWA3693 on chromosome 7A and IWB22624 and IWA4574 on chromosome 7B associated with the percentage volumes of A- and B-granules consistently identified in multiple environments were considered to be stable. Linear regression analysis showed a significantly negative correlation of the number of favorable alleles with the percentage volumes of A-granules and a significantly positive correlation between the number of favorable alleles and the percentage volumes of B-granules, respectively. The loci identified in this study and associated markers could provide basis for manipulating SG size to obtain superior noodle quality in wheat.  相似文献   

15.
Grain hardness is one of the most important quality characteristics of cultivated bread wheat (Triticum aestivum L.). A large deletion in the puroindoline a (Pina) gene or single nucleotide polymorphisms (SNPs) in the puroindoline b (Pinb) gene results in hard grain texture. So far, nine Pina alleles (Pina-D1aPina-D1b, Pina-D1kPina-D1q) and seventeen Pinb alleles (Pinb-D1aPinb-D1g, Pinb-D1pPinb-D1ab) have been identified in bread wheat. The major Pina and Pinb alleles identified in hard wheat cultivars are Pina-D1b, Pinb-D1b, Pinb-D1c and Pinb-D1d. In this study, a three-primer PCR system was employed to develop nine co-dominant STS markers for genotyping Pina-D1a and Pina-D1b, whereas temperature-switch (TS) PCR was used to develop six co-dominant SNP markers for genotyping the Pinb-D1a, Pinb-D1b, Pinb-D1c and Pinb-D1d alleles. These STS and TS-PCR markers were used to verify the grain hardness genotype of 100 wheat cultivars. The reliability and genotyping accuracy of TS-PCR markers were confirmed through sequencing of PCR products and a comparison with previously published results. Therefore, STS and TS-PCR markers offer a simple, cost-effective and reliable method for high-throughput genotyping Pina and Pinb alleles to select grain hardness in wheat quality breeding programs and for wheat market classification.  相似文献   

16.
Over the 5-year period (2000-2004), a significantly higher beta-glucan content was detected in the waxy varieties Washonubet, Wabet, and Wanubet (6.8-7.6%) and lines formed by crossing these varieties with malting varieties (5.8-7.1%). Conversely, the non-waxy hulled malting-type varieties Kompakt (4.0%) and Krona (4.3%) had significantly lower contents of beta-glucan. The observations also showed that concentrations of beta-glucans in 2000-2004 were significantly affected not only by varieties, but also environmental conditions in the growing periods and interactions of these two factors. Higher precipitation during the flowering time and grain filling period and lower temperatures during the flowering time in 2002 had negative effects on concentration of beta-glucans. Conversely, drier and warmer weather in 2003 enhanced the content of beta-glucans. The results show that it is possible to increase the content of beta-glucan in spring barley grain by implementing selective breeding practices. Compared to the parental malting varieties, the mean content of beta-glucans in F(4)-F(8) generations was increased by 1.8 and 2.0% by recombination in lines Kompakt x Wabet and Wanubet x Krona, respectively. Significant effect of environmental conditions and their interactions with varieties indicated the necessity to assess standard qualities of barley as a food material.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号