亚精胺诱导黄瓜幼苗对白粉病抗性的研究

以黄瓜品种‘长春密刺’幼苗为材料,研究了亚精氨(Spd)诱导黄瓜幼苗对白粉病的抗性,并测定Spd处理和白粉菌接种对黄瓜叶片4种防御酶活性及3种防卫基因表达的影响。结果显示:(1)0.2～1.0mmol.L-1 Spd对黄瓜幼苗白粉病抗性均有不同程度的诱抗效果,并以0.8mmol.L-1 Spd处理效果最明显,诱导效率可达55.3%。(2)喷施Spd或接种白粉菌均可提高黄瓜叶片过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、几丁质酶和β-1,3-葡聚糖酶的活性,且诱导并接种处理的植株叶片上述酶活性均比只诱导不接种处理的上升速度更快;同时,Spd处理和接种白粉菌可以提高植株叶片中POX、PAL、PR-1a基因的表达量。研究表明,Spd处理可以诱导防卫基因表达的增强,提高防御酶活性,显著降低病情指数,增强黄瓜幼苗对白粉病的抗性。     

诱抗菌激发子诱导黄瓜产生对炭疽病的抗性

用细胞壁提取法从诱抗菌中提取出激发子,经点滴法测定发现该激发子与活菌一样能诱导黄瓜产生对炭疽病的抗性反应。黄瓜经激发子处理后,体内与抗病反应有关的过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶活性显著增强;过氧化物酶同功酶酶带增多,着色加深;酚类物质和木质素含量也明显提高。     

Fusarium oxysporum f. sp. radicis-lycopersici can Induce Systemic Resistance in Barley Against Powdery Mildew

Drench inoculation of the undisturbed roots of barley seedlings with Fusarium oxysporum f. sp. radicis‐lycopersici (FORL) significantly reduced the primary infection frequency of Blumeria graminis f. sp. hordei (BGH) on the first leaves. The length of secondary hyphae and subsequent conidial production of BGH were also found to be significantly reduced by preinoculation with FORL. The reduction in infection frequency was observed as early as 48 h after inducer treatment, namely when plants were challenge‐inoculated immediately following inoculation with FORL. The induced resistance continued up to 16 days after treatment as indicated by the reduction in infection frequency, up to 22 days after treatment when evaluated as a reduction in the length of secondary hyphae, and up to 35 days after treatment when evaluated as a reduction in conidial production. Characteristics of FORL that may explain its success as an inducer of resistance against barley powdery mildew are discussed.     

苦瓜叶片结构与白粉病抗性的关系

以不同抗白粉病的苦瓜品系幼苗为材料,对它们的叶片及上下表皮厚度、栅栏组织及海绵组织厚度、叶片结构紧密度及疏松度、蜡质含量、比叶重、气孔及茸毛密度等叶片结构进行观察比较,探讨苦瓜白粉病抗性与其主要叶片结构指标的关系。结果显示:（1）抗病苦瓜品系叶片的蜡质含量显著高于感病品系,与病情指数呈显著负相关关系,蜡质层是其抵抗和延迟病原菌侵入的一个有力结构屏障。（2）感病品系叶片的气孔和叶背面茸毛数量显著多于抗病品系,且叶背面的气孔及茸毛密度与病情指数呈显著正相关关系,即气孔和茸毛越少越抗病。（3）抗病苦瓜品系的叶片栅栏组织以及海绵组织排列整齐、紧密,而高感品系的叶片组织出现大量孔隙,较难观察到完整细胞。（4）抗病品系叶片厚度、下表皮厚度、栅栏组织厚度、叶片结构紧密度明显高于感病品系,而感病品系的海绵组织厚度、叶片结构疏松度明显高于抗病品系;且苦瓜比叶重与其白粉病抗性关系不大。研究认为,苦瓜叶片蜡质含量、叶背面气孔及茸毛密度可以作为苦瓜白粉病抗性鉴定的参考指标。     

小麦白粉病抗性基因的聚合及其分子标记辅助选择

采用了在早代进行抗性鉴定、淘汰感病株、保留抗病株继续种植、较晚世代（F4代）进行抗性鉴定结合分子标记辅助选择的策略,提高了选到聚合抗性植株的效率。利用与Pm2、Pm4α、Pm8、Pm21紧密连锁或共分离的RFLP标记和PCR标记（SCAR标记）,对含有这些基因的优良品系间配制的杂交组合的F4代进行了分子标记辅助育种选择,并结合抗性鉴定,筛选到14株Pm4α Pm2I的植株,16株Pm2 Pm4α的植株,6株Pm8 Pm21的植株。应该引起注意的是,Pm2 Pm4α对混合白粉病菌的抗性达到高抗至免疫水平,而Pm2和Pm4α单独存在时抗性较差,表明聚合抗病基因植株的抗性提高了,为培育具有持久性抗性的品系或品种提供了新思路,它在实践和理论研究上都将具有重要意义。     

黄瓜霜霉病抗性遗传分析

通过2个抗感杂交组合,采用多世代联合的分离分析方法研究了黄瓜霜霉病抗性的遗传机制.结果显示,2个组合的最适遗传模型分别是2对加性-显性-上位性主基因 加性-显性-上位性多基因模型和2对等加性主基因 加性-显性多基因模型.组合I最优模型的主基因遗传率是56.84%~87.16%,多基因遗传率是0~34.93%;2个主基因的加性效应均为-15.191,加性效应较强,显性效应较弱,它们之间的加性与加性和加性与显性上位性效应较强.组合Ⅱ最优模型的主基因和多基因遗传率分别为48.92%和42.11%;2个主基因的加性效应皆为-13.505,显性效性均为0,它们之间不存在互作效应.结果表明,黄瓜霜霉病抗性,以加性效应为主,主基因遗传力较高,但是微效多基因效应也占相当的比重,所以,在霜霉病抗性育种中,要重视主基因,同时兼顾多基因效应.     

低聚糖素诱导橡胶树抗白粉病作用机制初探

通过比较喷洒低聚糖素后橡胶树叶片表皮细胞结构、过氧化物酶活性和酚类物质含量的变化表明,低聚糖素可诱导橡胶树的组织结构及生理生化过程发生变化。这些因素是低聚糖素提高橡胶树对白粉病抗病性的重要作用机制。     

硬粒小麦-粗山羊草双二倍体白粉病抗性的遗传分析与基因推导

对99份硬粒小麦-粗山羊双二倍体用北京地区流行的5号白粉菌生理小种进行了白粉病抗性鉴定,筛选出11个苗期抗病的双二倍体材料和2个全生育期抗病的材料M53和M81。对M53和M81及其硬粒小麦和粗山羊草亲本进行的抗白粉病鉴定结果表明,其抗性来源于粗山羊草。与M53和M81具有相同硬粒小麦亲本、不同粗山羊草亲本双二倍体的抗性结果也表明抗性基因来源于粗山羊草。对M53和M81的抗性遗传分析表明,它们均携带1个单显性抗病基因。用14个白粉菌生理小种对已知抗病基因品系与M53和M81两份待测材料进行接种鉴定,结果表明,M53和M81与已知基因的抗菌谱均不相同,M53与M81的抗菌谱也不相同,说明M53和M81各自分别携带1个新的显性抗白粉病基因。     

小麦抗白粉病基因定位与分子标记

对小麦抗白粉病基因的遗传定位与分子标记进行了综述,介绍了小麦抗白粉病的遗传,并对今后的研究方向进行了讨论。     

54份CIMMYT小麦材料抗白粉病分析

选用来自我国不同地区的20个白粉病菌毒性菌株,对54个CIMMYT小麦品种(系)进行抗病性分析.结果表明:(1)34个品种(系)含有抗病基因,以Pm8基因出现频率最高,有15个品种(系)携带该基因;(2)参试主效基因中,Pm1、Pm3e、Pm5、Pm6和Pm7基因已丧失对我国白粉菌的抗性,Pm16和Pm20基因的抗性最强;(3)50个1B/1R易位系品种(系)中31个含有抗病基因,48%的抗病1B/1R易位系可检测到Pm8基因.根据田间成株期病程曲线下面积(AUDPC)聚类分析结果,可将54份材料分为高抗、中抗、中感和高感4类,7个品种(系)不含任何主效抗病基因而田间表现中到高的抗性,是典型慢病性品种.     

精细定位甜瓜白粉病抗性基因Pm-M

以抗白粉病甜瓜品种MR1与感白粉病新疆地方品种新密1号为亲本,构建BC1P2和F2群体,研究白粉病菌Px1B(P.xanthii race 1B)的抗性遗传规律.以BC1P2与F2群体为试验材料,利用BSA(Bulked segregation analysis)结合分子标记技术发掘多态性信息,并开发分子标记进行抗性基...     

Benzothiadiazole Induces Resistance to Plasmopara helianthi in Sunflower Plants

A novel synthetic chemical CGA 245704 [benzo (1,2,3) thiadiazole-7-carbothioic acid S methyl ester (acibenzolar-S-methyl) (BTH)] applied as a soil drench and foliar spray was shown to provide good protection against Plasmopara helianthi in sunflower plants. Soil drenches at the rates of 150 and 200 mg/kg soil, were applied 3 days before the inoculation and induced high levels of protection (80–82%) against downy mildew. At the highest concentrations (up to 300 mg/kg soil) about 90% protection was observed but at these rates phytotoxic symptoms were noted. This compound also provided good protection against P. helianthi when applied 1 day before the inoculation as well as when applied 1 day post-inoculation. The chemical had no antifungal activity in vitro against P. helianthi . In addition the combination of CGA 245704 and metalaxyl, as a seed dressing at low rates, provided a high level of control against the disease; however, the activity of this combination was not significantly different from metalaxyl alone. CGA 245704 applied as a soil drench and foliar spray also protected sunflower plants from P. helianthi foliar infection.     

烟草白粉病抗性基因的遗传分析

以烟草抗白粉病品种台烟7号为母本,感病品种NC89为父本,构建6个世代的群体,利用主基因 多基因混合遗传模型的分离分析方法,研究烟草白粉病的抗性遗传规律。结果表明,烟草白粉病抗性的遗传是由两对加性-显性-上位性主基因 加性-显性-上位性多基因（E-0模型）控制的。B1、B2和F2世代主基因的遗传率分别为88.05%、32.62%、84.43%,主基因遗传率很大,说明可以在抗病育种早期进行选择;B1、F2世代多基因遗传率均为0.00%,说明烟草白粉病的发生受一定环境影响。     

Genetics of Powdery Mildew Resistance in Barley

A comprehensive, critical review on the present knowledge regarding the genetics of resistance of barley to the powdery mildew fungus is presented. The review deals with six kinds of resistance: Race-specific resistance; Mlo resistance; partial resistance; induced resistance; passive resistance; and non-host resistance. Most of the sections are subdivided into: phenotype of the interaction; resistance mechanisms; and genetics. A distinction is made between three groups of genes involved in the defense of plants to diseases: those that serve exclusively to mediate resistance; those that are mobilized to strengthen the plants' defense; and those that serve exclusively functions other than disease defense, but may bring about resistance. The more than 200 gene symbols assigned to race-specific mildew resistance genes over time are summarized and revised to 85 symbols that may be considered valid.     

与小麦白粉病抗性基因Pm2紧密连锁RAPD标记的筛选研究

以２５６个随机引物对含小麦抗白粉病基因Ｐｍ２近等基因系进行ＲＡＰＤ分析,发现１７个随机引物的扩增产物在抗、感ＮＩＬｓ材料间表现多态性,且其中５个引物经４次以上重复,均获相同结果,其多态性标记分别为ＯＰＭ０８(１６００)、ＯＰＩ０４(１７００)、ＯＰＨ１９(１１００、ＯＰＥ０９(９００)及ＯＰＭ１６(８５０)。当以这５个随机引物对１４个已知含Ｐｍ２基因的抗病材料及９个不含Ｐｍ２基因的感病材料进行检测时,只有标记ＯＰＩ０４(１７００)在１２个抗病材料中出现（另两个抗病材料中未检测到）,而在９个感病材料中均未出现。进一步用 ＯＰI(０４)对１０２株（Ｃｈａｎｃｅｌｌｏｒｘ Ｕｋａ／８＊Ｃｃ）Ｆ２分离群体进行分析,估算出标记ＯＰＩ０４(１７００)与Ｐｍ２基因间的遗传距离为１２．２±３．３ｃＭ。     

一个来自硬粒小麦的抗白粉病基因的鉴定和微卫星标记

在起源于硬粒小麦(TriticumdurumDesf.accessionDR147)和尾状山羊草(AegilopscaudataL.acc.Ae14)合成的双二倍体与普通小麦品种“莱州953”杂交组合衍生的BC3F2群体中鉴定了一个抗小麦白粉病基因。遗传分析表明,该基因为一个显性单基因。应用分离群体分组法(BSA),鉴定了两个与抗病基因紧密连锁的微卫星标记Xgwm311和Xgwm382,它们与抗病基因的遗传距离分别为5.9cM和4.9cM。对双二倍体亲本硬粒小麦DR147和尾状山羊草Ae14及轮回亲本“莱州953”的DNAPCR扩增结果表明,与抗病基因相关的微卫星标记Xgwm311和Xgwm382来源于硬粒小麦DR147。根据已发表的小麦微卫星图谱和对“中国春”缺-四体系DNA扩增结果,抗病基因被定位在小麦2A染色体的长臂末端。     

一个来自硬粒小麦的抗白粉病基因的鉴定和微卫星标记

在起源于硬粒小麦(Triticum durum Desf.accession DR147)和尾状山羊草(Aegilops caudata L.acc.Ae14)合成的双二倍体与普通小麦品种"莱州953"杂交组合衍生的BC3F2群体中鉴定了一个抗小麦白粉病基因.遗传分析表明,该基因为一个显性单基因.应用分离群体分组法(BSA),鉴定了两个与抗病基因紧密连锁的微卫星标记Xgwm311和Xgwm382,它们与抗病基因的遗传距离分别为5.9 cM和4.9 cM.对双二倍体亲本硬粒小麦DR147和尾状山羊草Ae14及轮回亲本"莱州953"的DNA PCR扩增结果表明,与抗病基因相关的微卫星标记Xgwm311和Xgwm382来源于硬粒小麦DR147.根据已发表的小麦微卫星图谱和对"中国春"缺-四体系DNA扩增结果,抗病基因被定位在小麦2A染色体的长臂末端.     

Use of Essential Oils in Control Strategies against Zucchini Powdery Mildew

The growing interest in the substitution of ‘synthetic pesticides’ by natural ones has fostered the research on vegetable sources and the screening of plant materials to identify new compounds. The aim of this study was to evaluate the efficacy of several essential oils used alone and alternating with a synthetic fungicide. Experimental trials were carried out in greenhouse during the years 2012–2013 testing four alternative application programmes. Chemical composition of the essential oils and evaluation of their residues on treated zucchini leaves were reported by a gas chromatography–mass spectrometry (GC/MS) analysis. Moreover, relative density analyses were carried out. The obtained results showed that the alternation of essential oils and synthetic chemicals can maintain a disease control, resulting that an integrated control management of zucchini powdery mildew is able to reduce the use of synthetic fungicides.     

小麦抗白粉病侵染初期的表达序列标签分析

以抗白粉病品系“百农 32 17×Mardler”　BC5F4为材料 ,构建了一个白粉病菌接种初期的抑制消减杂交cDNA文库 ,测序获得 76 0条ESTs。与GenBank序列进行BLASTx分析 ,获功能已知ESTs 2 71条。通过分析抗病相关基因 ,推测G蛋白介导的信号传导途径、SA信号传递系统、MAP相关信号传递系统等参与了小麦抗白粉病过程。SAR基因在抗病相关ESTs中的种类与数量最多。数据显示苯丙烷代谢途径、细胞壁结构修饰作用、细胞保卫机制参与了抗病过程。未知功能ESTs与GenBank序列进行BLASTn分析 ,其中许多与病原菌、非病原菌诱导cDNA文库来源的ESTs同源 ;新ESTs占全部ESTs的 16 6 %。     

外源亚精胺对甜瓜幼苗白粉病抗性的影响

以高感白粉病甜瓜‘066’、感病品种‘0544’、抗病品种‘Yuntian-930’为试材,对白粉病菌胁迫下外源亚精胺（Spd）处理的甜瓜幼苗叶片超氧化物岐化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）和多酚氧化酶（PPO）活性,以及过氧化氢（H₂O₂）、丙二醛（ MDA）和光合色素含量进行了研究,探讨外源Spd对甜瓜白粉病抗性的诱导效应及其生理机制。结果表明：（1）白粉病菌接种后甜瓜叶片的防御酶活性、光合色素含量先升后降,MDA含量升高;（2）外源Spd处理缓解了白粉病菌胁迫下甜瓜叶片防御酶活性、光合色素含量的下降,降低MDA含量及甜瓜的病情指数,并以1.0 mmol/L Spd处理效果最佳;（3）外源Spd处理使甜瓜叶片产生了更多的H₂O₂;（4）外源Spd提高甜瓜对白粉病抗性具有一定广谱性,且可向上传导。研究认为,H₂O₂可能参与白粉病胁迫下信号的传递,外源Spd可通过缓解白粉病菌胁迫下甜瓜防御酶活性和光合色素含量的下降来诱导甜瓜对白粉病的抗性。