离体叶段喷雾法建立小麦白粉病菌对三唑酮的敏感基线及其监测技术

为建立小麦白粉病菌对三唑酮抗药性的离体叶段喷雾法监测标准,采用该方法测定了2013年采自河南、河北省部分麦区的101个小麦白粉病菌野生菌株对三唑酮的敏感性。结果表明,小麦白粉病菌群体对三唑酮敏感性的EC50范围为0.239 8~7.558 5μg·mL-1,平均为3.561 2±1.881 3μg·mL-1;其敏感性均呈连续单峰曲线分布,可作为喷雾防治时小麦白粉病菌对三唑酮杀菌剂的敏感性基线。     

巴西蕉诱导的香蕉枯萎病菌1号和4号小种致病相关基因表达分析

目前对于香蕉枯萎病菌的致病分子机制尚不十分清楚。为了阐明枯萎病菌的致病分子机制,从香蕉枯萎病菌1号(Foc1)和4号小种(Foc4)的比较蛋白质组学分析发现的表达量差异较大的蛋白中,选取了9个致病相关蛋白或潜在的致病基因,利用荧光定量PCR方法进行基因表达谱分析。结果显示：与对照相比,巴西蕉处理的Foc4中,上调表达的基因有：酰胺转移酶基因（amidotransferase）、线粒体过氧化物还原酶基因（mitochondrial peroxiredoxin）、几丁质酶基因（chitinnase 1）、羧肽酶基因（carboxypeptidase cpds）,差异表达不明显的有腺苷激酶基因（adenosine kinase）、NADP-依赖型甘油脱氢酶基因（NADP-dependent glycerol dehydrogenase）、磷酸甘油酸激酶基因（phosphoglycerate kinase）、谷胱甘肽还原酶基因（glutathione reductase）、酰胺酶基因（amidase family protein）。Foc1中,与对照相比,上调表达的基因有：腺苷激酶基因、NADP-依赖型甘油脱氢酶基因,下调表达的基因有：酰胺转移酶基因、羧肽酶基因。综合分析显示,酰胺转移酶、过氧化物酶、几丁质酶、羧肽酶基因可能在Foc4的致病作用中起作用。     

小麦条锈菌毒性变异与DNA多态性的相关性

为了解小麦条锈茵毒性和DNA多态性之间的相关性,为SSR标记技术在条锈茵群体遗传分析中的应用提供理论依据,对90个小麦条锈茵茵系进行了毒性和DNA多态性分析.毒性分析发现17种致病类型或生理小种,SSR分子标记分析发现75个基因型,DNA指纹的多态性远比毒性的多态性丰富.不同小种有相同或相近的DNA指纹,同一小种可能有不同的DNA指纹.毒性特征和DNA多态性之间并不存在相关性,SSR标记技术可用于小麦条锈茵群体遗传分析.     

不同生态因子对匍茎草苔虫排氨率的影响

通过试验生态学方法,采用静水系统,对我国北方常见的污损生物匍茎草苔虫(Bugula stolonifera Ryland,1960)排氨率进行了初研究,主要包括匍茎草苔虫在饥饿状态下,温度对其排氨率的影响;温度和盐度交互作用对其排氨率的影响;温度和pH交互作用对其排氨率的影响。为预防控制海洋污损生物对养殖生物正常生长存活有着非常重要的意义,也为更深一步规划出有效的防治方法提供一定的基础科学依据。具体试验结果为:1.温度对匍茎草苔虫的排氨率具有极其显著的影响,在12~27℃范围内,呈1个峰值变化,在24℃时其排氨率达到最高值;2.温度与盐度的交互作用对其排氨率有显著的影响,在12~27℃条件下,盐度在16‰~40‰范围内,呈1个峰值变化,在盐度32‰时其排氨率达到最高值;3.温度与pH的交互作用对其排氨率有极其显著的影响,在12~27℃条件下,pH在5~10范围内,呈1个峰值变化,在pH为8时其排氨率达到最高值。     

香蕉枯萎病菌1号生理小种遗传转化体系的建立

利用农杆菌(Agrobacterium tumefaciens)介导的转化方法,建立香蕉枯萎病菌1号生理小种(Fusariumoxysporum f.sp cubense race 1)遗传转化体系,并对影响转化效率的因子进行优化,明确了高效转化的条件为:农杆菌OD600为0.15,AS诱导浓度为150μmol/L,诱导时间为7 h,Focr1-N2孢子浓度为1×106个/mL,潮霉素B筛选的浓度为150μg/mL,诱导培养基pH值为5.5,共培养温度为25℃,共培养时间为48 h为最佳条件。构建了包含1 200个突变体的突变体库,并对1 200个突变体进行了致病性测定,初步筛选出致病性丧失突变体20个,致病性显著减弱突变体18个,致病性严重增强突变体53个。     

草鱼三元病原菌融合子的构建及生物学特性

采用细胞融合技术首次将肠型点状产气单胞菌菌株和鱼害粘球菌菌株融合,构建二元融合菌株AM-1,再将AM-1与荧光假单胞菌菌株融合,构建三元融合菌株AM-2。对AM-1和AM-2菌株的形态结构、生理生化特性、致病性、抗原性、抗体效价进行分析。结果表明,AM-1活菌椭圆形,无鞭毛,死菌短杆状,AM-2菌株短杆状,有鞭毛,它们的生理生化性状介于3原始亲本菌株之间;用AM-2菌株对当年健康草鱼种进行人工感染攻毒,被攻毒草鱼种具有烂鳃病、赤皮病及肠炎病的部分症状;AM-2菌株抗原的受免草鱼种对荧光假单胞菌、鱼害粘球菌和肠型点状产气单胞菌菌株的免疫保护率分别达64.90％、68.00％、67.00%,抗体效价最高达1∶256、1∶256、1∶512。测定了AM-1和AM-2菌株及亲本DNA含量并进行了琼脂糖凝胶电泳分析,AM-1和AM-2菌株DNA含量明显高于任一原始亲本。图4表6参23     

Induction of Defense Gene Expression and the Resistance of Date Palm to Fusarium oxysporum f. sp. Albedinis in Response to Alginate Extracted from Bifurcaria bifurcata

In many African countries, the Bayoud is a common disease spread involving the fungus Fusarium oxusporum f. sp. albedinis (Foa). The induction of plant natural defenses through the use of seaweed polysaccharides to help plants against pathogens is currently a biological and ecological approach that is gaining more and more importance. In the present study, we used alginate, a natural polysaccharide extracted from a brown algae Bifurcaria bifurcata, to activate date palm defenses, which involve phenylalanine ammonia-lyase (PAL), a key enzyme of phenylpropanoid metabolism. The results obtained showed that at low concentration (1 g·L⁻¹), alginate stimulated PAL activity in date palm roots 5 times more compared to the negative control (water-treated) after 24 h following treatment and 2.5 times more compared to the laminarin used as a positive stimulator of plant natural defenses (positive control of induction). Using qRT-PCR, the expression of a selection of genes involved in three different levels of defense mechanisms known to be involved in response to biotic stresses were investigated. The results showed that, generally, the PAL gene tested and the genes encoding enzymes involved in early oxidative events (SOD and LOX) were overexpressed in the alginate-treated plants compared to their levels in the positive and negative controls. POD and PR protein genes selected encoding β-(1,3)-glucanases and chitinases in this study did not show any significant difference between treatments; suggesting that other genes encoding POD and PR proteins that were not selected may be involved. After 17 weeks following the inoculation of the plants with the pathogen Foa, treatment with alginate reduced the mortality rate by up to 80% compared to the rate in control plants (non-elicited) and plants pretreated with laminarin, which agrees with the induction of defense gene expression and the stimulation of natural defenses in date palm with alginate after 24 h. These results open promising prospects for the use of alginate in agriculture as an inducer that triggers immunity of plants against telluric pathogens in general and of date palm against Fusarium oxysporum f. sp. albedinis in particular.     

小型植保无人机超低量喷雾对荒漠绿洲麦区小麦白粉病的防治效果

研究小型植保无人机超低量喷雾对小麦白粉病的防治效果,为科学使用小型植保无人机防控小麦病害提供指导。采用随机区组的方法,定点调查各处理小麦白粉病发生情况,评价供试药剂对小麦白粉病的防治效果。结果表明,240 g/L氯氟醚·吡唑酯SC 180 g/hm²、19%啶氧·丙环唑SC 199.50 g/hm²和 23%醚菌·氟环唑 SC 103.50 g/hm²添加增效剂迈飞对小麦白粉病具有较好的防效,防效分别为77.88%、74.23%和 73.26%。42%苯菌酮 SC 189.00 g/hm²、430 g/L戊唑醇悬浮剂SC 129.00 g/hm²、75%肟菌·戊唑醇 WG 202.50 g/hm²和 40%腈菌唑 WP 120.00 g/hm²添加增效剂迈飞对小麦白粉病防效在60.90%～65.72%之间。7 种药剂均可用于小型植保无人机超低量喷雾防治小麦白粉病,为了减缓抗药性的产生,建议在生产上轮换使用。     

赣南引种八角(八角科)播种育苗技术

首次报道八角在江西赣南的播种育苗技术。     

Assessment of the profile of powdery mildew and its damage function at low disease intensities in field experiments with winter wheat

Damage by mildew to winter wheat was studied in 11 field experiments in the Netherlands. Damage is described by the simple function: –0.013 (SE=0.003) kg are^–1 per pustule-day of mildew per leaf, from second node stage to early dough at yield levels of 70 to 90 kg are^–1, in diseasefree plots. No deviations from linearity at disease stresses from zero to two thousand pustuledays per leaf were observed. Years, cultivars or soil types did not affect the damage function significantly. The effects of mildew on some yield components were suggested.Mildew profiles in untreated plots could be described by the equation: CM=CLA^b, in which CM and CLA are the cumulative pustule number and the cumulative leaf area, respectively, calculated both from top to bottom of the canopy, and totals standardized at unity. Estimates of the gradient parameter b aveaged 3.4 (SE=0.9). Observed differences in steepness of the profiles did not affect the damage function significantly.Samenvatting Opbrengstderving van wintertarwe door meeldauw werd bestudeerd in 11 veldproeven in Nederland. De schade bedroeg gemiddeld 0.013 (SE=0.003) kg are^–1 per puistdag meeldauw per blad, vanaf het tweede-knoop stadium tot begin deegrijp bij opbrengstniveaus van 70 tot 90 kg are^–1, in de blanco. Bij een ziektestress van 0 tot 2000 puistdagen meeldauw per blad werd geen afwijking van een rechtlijnig verband gevonden. De schaderelatie werd niet significant beïnvloed door de verschillende jaren, rassen of grondsoorten. Het effect van meeldauw op enkele opbrengstcomponenten werd aangetoond.Meeldauwprofielen in de onbehandelde veldjes konden worden beschreven met de vergelijking: CM=CLA^b, waarin CM het cumulatieve aantal puistjes is en CLA het cumulatieve bladoppervlak, beide berekend van bovenin het bladerdek naar beneden, de totalen gestandaardiseerd op één. De gradiënt parameter b bedroeg gemiddeld 3.4 (SE=0.9). Waargenomen verschillen in steilte van de meeldauwprofielen beïnvloedde de schaderelatie niet aantoonbaar.