Quantitative Trait Loci for Resistance Against Fusarium Wilt Based on Three Cotton F_2 Populations

Fusarium wilt （FW） is one of the most common cotton diseases in the world. Identification of QTLs conferring resistance to FW is key for the incorporation of resistance genes into elite cultivars. Two intraspecific （cross between Gossypium hirsuturn L.） and one interspecific （cross between Gossypium hirsutum L. and Gossypium bardence L.） F2 populations were constructed by using a highly resistant cultivar and crossing it to a susceptible cultivar with 154, 79, and 148 offsprings, respectively. Simple sequence repeats （SSR） were used to screen genomic regions closely linked to FW resistance. The results showed that five QTLs associated with FW resistance were detected in two intraspecific populations using a composite interval mapping method under four different conditions. Four of these loci located on Chr. 2/Chr. 17 neighboring markers JESPR304 or CIR305 which explained 13.1 to 45.9% of the phenotypic effect. Furthermore, JESPR304 and CIR305 were previously testified and found to be tightly linked. It is possible that these four QTLs detected under different conditions were the same resistance QTL/gene. We consider that there is the possibility of a major FW resistant gene in intraspecific populations. In the interspecific mapping populations two QTLs were detected on Chr. 9 and Chr. 12/26 which explained great phenotypic variance of 49.4 and 45.7%. As the location of QTLs for FW resistance among the intraspecific and the interspecfic populations were totally different, it is suggested that there may be different resistance mechanisms between G. bardence L. and G. hursutum L. Thus, the present research provides an opportunity to understand the genetic control of resistance to FW in Gossypium hirsutum and Gossypium bardence and to conduct MAS in breeding programs to develop FW resistant cultivars.

Advances in Cotton Breeding for Resistance to Fusarium and Verticillium Wilt in the Last Fifty Years in China

This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.

Test on Wilt-Resistance of Simple Hybrides F7 and Beckross Hybrid Lines F6 B1 of <i>G. hirsutum</i>L. of Cotton to New Virulent Isolates of Fungus <i>Fusarium verticillioides</i>and <i>Verticillium dahliae</i>

The article presents the results of studies on the resistance of hybrid cotton lines to a new virulent isolate (strain) of the fungus Fusarium verticillioides upon inoculation of the host plant. Based on the studies, it was found that the complex genotypic resistance of the studied lines, when the host plants are inoculated with isolates of -100 V. dahliae Kleb fungus and 103 Fusarium verticillioides fungi, depends on the degree of resistance of the parental forms and their combination ability.

Studies on Cotton Breeding Resistant to Fusarium and Verticillium wilt Diseases

Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have

Efficacy evaluation and mechanism of Bacillus subtilis EBS03 against cotton Verticillium wilt

Background:In our previous study,a strain EBS03 with good biocontrol potential was screened out of 48 strains of cotton endophyte Bacillus subtilis by evaluating the controlling effect against cotton Verticillium wilt.However,its mechanism for controlling Verticillium wilt remains unclear.The objective of this study was to further clarify its con-trolling effect and mechanism against cotton Verticillium wilt.Results:The results of confrontation culture test and double buckle culture test showed that the inhibitory effects of EBS03 volatile and nonvolatile metabolite on mycelium growth of Verticillium dahliae were 70.03%and 59.00%,respectively;the inhibitory effects of sporulation and microsclerotia germination were 47.16%and 70.06%,respec-tively.In the greenhouse test,the EBS03 fermentation broth root irrigation had the highest controlling effect at 87.11%on cotton Verticillium wilt,and significantly promoted the growth of cotton seedlings.In the field experi-ment,the controlling effect of EBS03 fermentation broth to cotton Verticillium wilt was 42.54%at 60 days after cotton sowing,and the boll number per plant and boll weight in EBS03 fermentation broth seed soaking,root irrigation,and spraying treatments significantly increased by 19.48%and 7.42%,30.90%and 2.62%,15.99%and 9.20%,respec-tively.Furthermore,EBS03 improved the resistance of cotton leaves against the infection of V.dahliae,and induced the outbreak of reactive oxygen species and accumulation of callose.In addition,the results of real time fluorescent quantitative polymerase chain reaction(RT-qPCR)detection showed that EBS03 significantly induced upregulation expression level of defense-related genes PAL,POD,PPO,and PR10 in cotton leaves,enhanced cotton plant resistance to V.dahliae,and inhibited colonization level of this fungal pathogen in cotton.Conclusion:Bacillus subtilis EBS03 has a good biological defense capability,which can inhibit the growth and coloni-zation level of V.dahliae,and activate the resistance of cotton to Verticillium wilt,thus increase cotton yield.

Induction of Tolerance to Fusarium Wilt and Defense-Related Mechanisms in the Plantlets of Susceptible Berangan Banana Pre-Inoculated with Pseudomonas sp.(UPMP3) and Burkholderia sp.(UPMB3)

This study is aimed at assessing the ability of two endophytic bacteria originally isolated from healthy oil palm roots, Pseudomonas sp. （UPMP3） and Burkholderia sp. （UPMB3） to induce resistance in susceptible Berangan banana against Fusarium oxysporum race 4 （FocR4）. Increased accumulation of resistance-related enzymes such as peroxidase （PO）, phenylalanine ammonia lyase （PAL）, lignithioglycolic acid （LTGA）, and pathogenesis-related （PR） proteins （ehitinase and β-1,3-glucanase） has been observed in plantlets treated with endophytic bacteria UPMP3 and UPMB3 singly or as mixture under glasshouse conditions. Pre-inoculation of banana plantlets with UPMP3 showed a significant reduction in Fusarium wilt incidence 72 d after challenged inoculation with FocR4. UPMB3 was less effective in suppressing Fusarium wilt compared to UPMP3, whereas, the mixture of both endophytes showed an intermediate effect. Based on these results, it is concluded that UPMP3 could be a promising biological control agent that can trigger resistance against Fusarium wilt in susceptible Berangan banana.

Gh_D11G050000参与棉花黄萎病抗性的功能分析

【目的】克隆Gh_D11G050000基因,解析其在棉花黄萎病抗性反应中的功能和作用机制,为开展棉花抗病分子育种提供理论依据。【方法】利用生物信息学方法分析Gh_D11G050000基因的序列特征和系统进化关系。通过实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction, qRT-PCR)分析该基因的表达模式以及大丽轮枝菌(Verticillium dahliae)侵染后的表达量变化。利用病毒诱导的基因沉默(virus-induced gene silencing, VIGS)技术初步验证该基因的功能。通过转录组测序分析和相关基因的表达量测定初步解析其抗病机制。【结果】Gh_D11G050000与Gh_A11G049600和Gr_11G034620蛋白的亲缘关系最近。qRT-PCR分析发现,Gh_D11G050000在棉花根部的表达量最高;该基因的表达量在大丽轮枝菌侵染后显著增加。Gh_D11G050000沉默植株对大丽轮枝菌的抗性减弱,具体表现为茎秆维管束褐变加重,有病菌繁殖的茎段数量明显增加,病株率和病情指数显著升高。转录组及qRT-PCR分析表明,Gh_D11G050000沉默棉株中茉莉酸、乙烯信号通路和木质素合成途径中相关基因的转录水平降低。【结论】Gh_D11G050000通过影响木质素合成基因、茉莉酸和乙烯信号通路相关基因的表达正调控棉花对黄萎病的抗性。

尖镰孢5-氧脯氨酸酶基因的鉴定及功能分析

【目的】5-氧脯氨酸酶(5-oxoprolinase,OXP)是γ-谷氨酰循环中6种核心酶之一。鉴定尖镰孢(Fusariumoxysporum)5-氧脯氨酸酶基因,明确其与尖镰孢致病力的关系,为解析尖镰孢致病分子机制以及棉花枯萎病防治提供理论依据。【方法】利用生物信息学方法从尖镰孢基因组中鉴定FoOXP,分析其基因结构、编码蛋白的结构域、染色体定位及进化关系。通过基因敲除突变株和回补菌株分析FoOXP2突变后尖镰孢的表型,并检测突变株和野生型菌株对棉花幼苗的致病力差异。利用寄主诱导的基因沉默(host-inducedgenesilencing,HIGS)技术调查转化棉花的病级率及病情指数。利用实时荧光定量PCR(qRT-PCR)技术检测棉花中真菌生物量和转化FoOXP2干扰片段的棉花茎中FoOXP2的表达量。【结果】在尖镰孢基因组中共鉴定出两个FoOXP(FoOXP1和FoOXP2),其编码序列长度分别为4080和3921 bp,分别编码1359和1306个氨基酸,蛋白质分子量分别为14.90和14.07kDa,理论等电点分别为5.73和5.30。FoOXP1蛋白定位于线粒体,FoOXP2蛋白定位于细胞骨架。FoOXP1位于染色体JH657921,FoOXP2位于染色体JH657938,未形成基因簇,其序列相似性为52.00%。系统发育分析发现,FoOXP1和FoOXP2分属于两个亚群。与野生型菌株相比,FoOXP2敲除突变株产孢量和孢子萌发率显著降低,穿透能力丧失,对刚果红和山梨醇的耐受力有所增强,但对细胞壁胁迫(SDS和CFW)、氧化胁迫(H_(2)O_(2))和渗透胁迫(NaCl和KCl)更敏感。同时,对棉花的致病力显著下降。HIGS结果表明,接菌14和21 d后,FoOXP2基因沉默后的棉花植株发病明显减轻,其病情指数(17.3和40.2)显著低于对照(28.2和77.1),FoOXP2表达量和真菌生物量显著低于对照。【结论】FoOXP2正向调控尖镰孢的致病力,推测其在宿主-病原体互作过程中发挥重要作用。

枯草芽孢杆菌B579对黄瓜枯萎病的防治及其诱导抗性研究

【目的】探究枯草芽孢杆菌B579对黄瓜枯萎病菌的生防效果及诱导抗性机理。【方法】采用平板对峙试验和温室盆栽试验,检测病原菌生长及形态变化、植物生长量、叶片防御酶活性、丙二醛含量、防御相关基因表达量等指标。【结果】枯草芽孢杆菌B579对黄瓜枯萎病菌具有较强的抑制作用,抑菌圈周围菌丝出现粗细不均、膨胀、断裂等现象。盆栽试验表明B579对黄瓜枯萎病的防治效果为78.80%。B579处理组黄瓜幼苗的株高、茎粗、鲜重、干重分别比对照组增加了13.87%、4.17%、15.15%、12.77%。相比单独接种病原菌(FOC)处理,接种B579再接种病原菌(B579+FOC)处理在第4天和第7天显著提高了黄瓜叶片苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性,并减少黄瓜叶片丙二醛(MDA)的含量(P<0.05)。实时荧光定量PCR检测结果表明,接种B579再接种病原菌后,黄瓜叶片防御相关基因LOX、PR1、PR3和CAT表达量在第4天和第7天显著高于其他处理(P<0.05)。【结论】枯草芽孢杆菌B579能够通过直接抑制病原菌生长和使黄瓜产生诱导抗性来有效防治黄瓜枯萎病。

转几丁质酶和β-1,3-葡聚糖酶基因提高棉花对枯萎病和黄萎病的抗性

枯、黄萎病是世界棉花生产中的两大重要病害。传统育种缺乏抗源,几丁质酶和β-1,3-葡聚糖酶是植物防御体系中的两种防卫因子,两者之间存在协同增效作用。据此构建了4个单价和2个双价基因(分别定位于细胞内或细胞外)的植物表达载体,通过花粉管通道法转化棉花,经PCR和Southern杂交检测以及1996～2000年温室及病圃多代筛选鉴定,已培育出对枯、黄萎病抗性提高的转基因棉花株系。将抗病基因导入国产抗虫棉品种GK19中,还获得了兼抗病、虫的转基因优系。

中国棉花抗枯、黄萎病育种50年

综述了我国棉花抗枯、黄萎病育种研究进展 ,内容包括 5 0年来取得的成就、经验 ,存在的问题及对策 ,是对我国棉花抗病育种工作较为全面的总结。

中国抗枯、黄萎病陆地棉材料分子水平的遗传差异评价

采用SSR和AFLP分子标记技术,对中国不同年代培育的54个抗枯、黄萎病陆地棉品种(系)分子水平的遗传差异进行了研究。22对SSR引物和20个AFLP引物组合共扩增出446个多态性标记,每个品种平均8.26个。采用SPSS11.5软件计算欧氏距离,中国抗病品种间欧氏距离分布在5.568～11.790之间,平均值为8.906;单一品种欧氏距离平均值为8.530～10.011,高于欧氏距离总平均值的品种共10个,占品种总数的18.52%;85.55%的品种欧氏距离值分布于7.000～10.000之间,表明中国供试抗病品种群体的遗传基础较为狭窄。作为比较对照的4个国外品种间欧氏距离变化在9.055～10.724之间。国内品种与国外品种之间的欧氏距离介于6.481～12.490,82.02%的品种欧氏距离值分布于8.000～11.000之间,表明国外品种与国内品种之间遗传差异较大。基于SSR和AFLP整合数据的聚类分析,58个品种被划分为5个SAG(SSR&AFLP-basedgroups)分子类群,SAG的划分与品种系谱来源有较强的相关性。

我国棉花抗枯、黄萎病骨干品种(系)基于AFLP的遗传多样性

利用AFLP分子标记技术,对我国20世纪50年代开展抗枯、黄萎病育种以来培育的105份骨干品种(系)的遗传多样性进行了研究。结果表明,筛选的20个AFLP引物组合在该品种群体中扩增了1498个AFLP标记,其中多态性标记232个,占总标记数的15.5%。单一引物组合扩增的DNA标记数变化在49111之间,平均每个引物组合扩增的总标记和多态性标记分别为74.9和11.6。在该抗病品种群体中,有46个品种(系)具有特异标记,占品种总数的43.81%,其中引物组合E41/M50可使10个品种产生特异标记。品种(系)之间的成对欧氏距离总平均值为4.353,变幅为1.7326.708,单一品种欧氏距离平均值变幅为3.5315.705,高于总平均值的品种数不足50%,表明该陆地棉抗病品种群体的遗传多样性较低。基于AFLPs多态性数据的聚类分析,105个品种(系)被划分为5个陆地棉品种类群(Uplandcottongroups,UCGs),每个UCG包含的品种数目不同。

3株放线菌对甜瓜幼苗的促生与抗性诱导作用

【目的】研究3株生防放线菌Act1、Act11和Act12对甜瓜枯萎菌(TF)和西瓜枯萎菌的拮抗性,及其对甜瓜幼苗的促生作用和叶片多酚氧化酶(PPO)活性的诱导作用,为防治西甜瓜枯萎病提供高效生防放线菌。【方法】通过琼脂块法和无菌发酵滤液试验,研究了3株放线菌对TF和西瓜枯萎菌的拮抗性及其无菌发酵滤液对甜瓜种子胚轴、胚根生长的影响;通过盆栽试验,研究了3株放线菌对甜瓜幼苗叶绿素相对含量、甜瓜根系质量和根系活力的影响以及对甜瓜叶片PPO活性的诱导作用。【结果】①供试放线菌对TF和西瓜枯萎菌的拮抗圈直径均超过17mm,其无菌发酵滤液对TF和西瓜枯萎菌的抑菌率为2.65%~65.27%,且能促进甜瓜胚轴、胚根生长,提高甜瓜种子活力。②放线菌Act1、Act11和Act12以1.5 g/kg的接种量与TF混接,甜瓜幼苗叶绿素相对含量较单接TF分别增加了17.57%,13.54%和11.59%,差异显著(P<0.05);放线菌Act11以1.5 g/kg接种量与TF混接,甜瓜幼苗根系质量较单接TF处理增加了53.33%;放线菌Act1和Act12以2.0 g/kg接种量与TF混接,甜瓜幼苗根系活力较单接TF分别增加了4...

棉花对枯黄萎病的抗性鉴定及病害对产量的影响

对来自长江流域棉区的 5 0份陆地棉新品系 (品种 )进行了抗枯萎病 (Fusariumvasinfectum)或抗黄萎病 (Verticilliumalboatrum)鉴定 ,并从中选择 10个新品系为试验材料 ,对枯萎病和黄萎病各级病株所造成的籽棉产量损失进行了研究。试验结果表明 :(1)有 4个品系抗枯萎病 ,占抗枯萎病鉴定材料 (40份 )的 10 0 % ;耐病 2 7个 ,占 6 7 5 % ;感病 9个 ,占2 2 5 %。 (2 )有 1个品系抗黄萎病 ,占抗黄萎病鉴定材料 (30份 )的 3 3% ;耐病 2 6个 ,占 86 7% ;感病 3个 ,占 10 0 %。 (3)棉花枯萎病株 ,不同的发病级别与健株相比造成的籽棉减产百分率分别为 :Ⅰ级 32 0 % ;Ⅱ级 5 2 9% ;Ⅲ级 6 8 7% ;Ⅳ级83 4 %。 (4)棉花黄萎病株不同的发病级别与健株相比所造成的籽棉减产百分率为Ⅰ级 30 3% ;Ⅱ级 5 1 9% ;Ⅲ级6 8 4 % ;Ⅳ级 86 7%。

过氧化物酶在棉花对枯萎病抗病性中的作用

分析了氟乐灵（２μｇ／ｇ土）诱发处理及枯萎病菌侵染后棉苗叶片和根茎部不同细胞定位过氧化物酶（ＰＯＤ）活性的变化．结果表明：（１）总可溶性ＰＯＤ、胞内ＰＯＤ、胞间ＰＯＤ以及细胞壁结合型ＰＯＤ的活性抗病品种高于感病品种；（２）氟乐灵诱发处理及枯萎病菌侵染可提高棉苗组织中上述五类ＰＯＤ的活性，细胞间隙ＰＯＤ及胞壁结合ＰＯＤ活性上升更为明显；（３）枯萎病菌侵染后经氟乐灵诱发处理并产生诱导抗性的棉苗及抗病品种棉苗中胞壁结合ＰＯＤ活性快速上升，增加幅度大，而感病品种前期无明显增加，后期才有较小幅度的上升．

4株拮抗细菌对棉花黄萎病的防治效果及机制

棉花黄萎病严重制约新疆棉花持续高产和稳产,拮抗细菌在棉花黄萎病生物防治中潜力巨大。本研究旨在明确4株拮抗细菌对棉花黄萎病的防治效果及其机制,为棉花黄萎病的生物防治提供理论依据。本文采用共培养法,研究4株拮抗细菌对黄萎病菌分生孢子浓度、菌丝和孢子形态、膜透性和产毒素能力的影响,采用滤液接种法进行盆栽试验验证其对棉花黄萎病的防治效果,采用愈创木酚法和氮蓝四唑光化还原法测定棉株体内防御酶系的活性。结果表明,4株拮抗细菌能够减少黄萎病菌分生孢子浓度,破坏其细胞形态,导致其细胞膜破裂,降低其毒蛋白浓度。接种4株拮抗细菌,能够诱导棉株体内POD酶和SOD酶等防御酶系的积累,提高了棉花的抗病能力,由菌株SHZ-24、SHT-15、SMT-24和BHZ-29处理的棉花,其对棉花黄萎病的最高防治效果分别为73.82%、80.48%、84.91%和84.18%。4株拮抗细菌通过抑制黄萎病菌的生长和诱导植物产生防御反应来提高对棉花黄萎病的抗性,其对棉花黄萎病具有良好的防治效果。

棉花抗枯、黄萎病育种技术研究

目的研究棉花抗枯、黄萎病育种技术,选育棉花抗枯、黄萎病的多抗性新品种。方法试验采用致病力强的菌种,培养备制成棉枯萎病棉籽粉载菌体和棉黄萎病孢子悬浮液,研究不同菌量、不同接菌方法、致病温度因素、病圃接菌选择及多抗病性育种选择技术指标。结果播前土壤接棉枯萎病菌棉籽粉载菌体,棉苗2片真叶时,伤根接黄萎病菌孢子悬浮液,盖膜保温诱导发病,淘汰感病群体及感病个体。大田病圃是在重病地接种发病棉杆,移栽时再用棉黄萎病菌孢子悬浮液沾根,发病高峰淘汰棉枯、黄萎病感病群体及感病个体,结合丰产、优质性状的遗传选择,培育出抗病棉花品种。结论该项技术是在研究棉花苗期诱导抗性和大田病圃筛选相结合构建的新方法。

水杨酸诱导棉花耐黄萎病的效应

温室内以黄萎病菌(Verticilli-umdahliae)孢子悬浮液接种棉苗30min后,再以2mmol的水杨酸(SA)叶面喷施,处理棉苗与对照相比发病率和病情指数都有所降低,表现出对棉花黄萎病具有一定的诱导抗病性。经对一些生化指标进行测定,发现用SA喷施和病菌接种都可以引起棉苗叶片中过氧化物酶(POD),苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO),β-1,3-葡聚糖酶活性的上升,这可能是导致诱导抗病性产生的重要原因。

中生菌素和氨基寡糖素对西瓜枯萎病防治试验

通过室内和田间试验 ,评价了中生菌素和氨基寡糖素与多菌灵混用对西瓜枯萎病的防治效果。结果表明 ,中生菌素室内抑菌效果明显 ,与多菌灵混用的田间防效和西瓜增产率分别为 84.12 %和 10 4.6 1%,均极显著优于其他药剂处理。氨基寡糖素诱导西瓜抗枯萎病效果明显 ,盆栽试验发病轻 ,植株健壮 ,根系发达 ,田间试验防病增产效果显著。