Comparative proteomic analysis of cucumber roots infected by Fusarium oxysporum f. sp. cucumerium Owen

Cucumber Fusarium wilt (CFW), caused by the soil-borne fungus Fusarium oxysporum f. sp. cucumerium, is a serious disease in cucumber (Cucumis sativus) production worldwide. For the efficient control of the pathogenic fungi, a better understanding of its interaction and associated resistance mechanisms at the molecular level is required. Here, we report a comparative proteomics analysis of total root protein isolated from infected cucumber root of susceptible bulk (SB) and resistant bulk (RB) of cucumber generation F2. Two-dimensional gel electrophoresis (2-DE) coupled with MS/MS approaches identified 15 over-accumulated proteins from the RB plants. Identified proteins are mainly involved in defense and stress responses, oxidation reduction, metabolism and transport and other process. These proteins are likely to be a part of resistance-related protein network, playing different roles in cucumber disease resistance. Three vital clues regarding wilt resistance of C. sativus are gained from this study. First, jasmonic acid and redox signaling components were found in response to F. oxysporum infection in resistant plants. Second, the LRR family protein may play an important role in the defense reaction against CFW. Third, biotic and abiotic stress-related proteins were induced by the CFW fungus F. oxysporum, indicating the activation of common stress pathway.     

草鱼PRL基因多态性与幼鱼生长性状和肌肉成分的关联分析

为了探索草鱼(Ctenopharyngodon idella)PRL(prolactin)基因多态性与草鱼生长性状和肌肉成分的关联性,通过测序法从10尾草鱼的PRL基因中筛选到6个突变率高于30%的变异位点,包括5个单核苷酸变异位点和1个插入型突变(–/CACTCACTA),分别命名为2551GA、2639GC、3247AG、5197TG、5897GA和3391–+。利用AS-PCR(allele-specific PCR)和基因分型技术对192尾4月龄草鱼的PRL基因变异位点进行检测;基于一般线性模型对变异位点多态性与草鱼生长性状和肌肉成分进行相关性分析。研究发现,2639GC、3391–+和5197TG对体长和体重具有显著影响(P0.05),2639GC对肌肉粗蛋白含量具有显著影响(P0.05)。单个位点基因型比较发现,3391–+的突变型(–+和++)个体的体长和体重均显著高于野生型(––)个体(P0.05);2639GC的GC及5197TG的突变型(TG和GG)个体的体长和体重分别显著低于2639GC的GG和5197TG的TT野生型(P0.05);2639GC突变型(CC)个体的粗蛋白含量显著高于2639GC其他基因型(GG和GC)个体(P0.05)。两位点组合比较发现,含3391–+突变型(–+和++)的组合对应体长和体重普遍高于其他组,含2639GC的CC突变型的组合对应粗脂肪含量和粗蛋白含量普遍较高,其中粗蛋白含量显著高于其他组(P0.05)。研究表明,草鱼PRL基因多态性与草鱼生长性状和肌肉成分间存在显著关联,推测相关变异位点可作为草鱼生长和肉质改良的候选辅助标记。     

牛源大肠杆菌O157:H7的分离鉴定

为调查新疆部分地区E.coli O157：H7的感染情况和菌株致病性,从新疆阿克苏、伊犁、塔城3个地区的牛场采集新鲜粪样564份,对E.coli O157：H7进行分离与鉴定。利用E.coli营养肉汤（EC肉汤）对样品进行增菌后,用山梨醇麦康凯培养基（SMAC）平板选择性培养,再经过4-甲基伞形酮-β-D葡萄糖醛酸苷培养基（MUG）的筛选,对疑似菌株进行生化和PCR鉴定,并将分离鉴定到的菌株进行小鼠攻毒试验。结果显示,从伊犁地区采集的样品中共分离出2株E.coli O157：H7（Y166和Y226）,其检出率为0.88%;小鼠攻毒试验中,Y166和Y226试验组小鼠在48 h内全部死亡,具有一定致病性;从阿克苏、塔城所采样品中未分离到E.coli O157：H7。     

Abiotic soil properties and the occurrence of Rhizoctonia crown and root rot in sugar beet

Since 1993, Rhizoctonia crown and root rot (Rhizoctonia solani AG 2–2 IIIB) has represented an increasing problem for sugar beet production in Germany. Up to now, the outbreak of the infection and the spread of the disease within a field cannot be predicted and effective countermeasures are not available. Although little is known about the living conditions of R. solani in soils, abiotic soil properties are likely to influence the disease occurrence. Investigations were carried out based on 60 pairwise comparisons, each consisting of a disease‐affected and an adjacent nonaffected patch on farmers' fields in 2002 and 2003. Soil samples from the top soil layer (0–30 cm) were collected before harvest, and eight of the most frequently mentioned soil properties potentially influencing Rhizoctonia crown and root rot infection were examined: bulk density, texture, carbonate carbon, potassium, phosphorus, organic carbon, total nitrogen, and pH. The occurrence of the disease was significantly related to the soil C : N ratio, indicating the influence of soil organic matter on the disease occurrence. Examinations of soil thin sections showed that organic‐matter particles in the soil serve as a substrate for R. solani. All other soil physical and chemical properties examined did not differ between the disease‐affected and nonaffected patches and seem to be of minor importance.     

不同栽培模式下春玉米籽粒灌浆特性的研究

以金山27和先玉335为供试品种,在西辽河平原研究了农户模式(目标产量11.25 t.hm-2,以NH表示)、高产模式(目标产量12.75.thm-2,以GC表示)和再高产模式(目标产量14.25 t.hm-2,以ZGC1、ZGC2表示,ZGC1和ZGC2密度相同,施肥时期不同)下春玉米籽粒灌浆特性。结果表明,不同栽培模式下玉米籽粒灌浆过程均可用Logistic方程进行描述,2个品种籽粒的终级生长量,除先玉335中下部籽粒外均表现为NH>GC>ZGC1>ZGC2。2个品种起始生长势均表现为NH>GC>ZGC,其中,金山27表现为ZGC1>ZGC2,先玉335则为ZGC2>ZGC1。4种栽培模式下最大灌浆速率和平均灌浆速率均表现为NH>GC>ZGC2>ZGC1,达到最大灌浆速率的时间均以NH最快,ZGC2最慢;有效灌浆期总体上表现为ZGC1>ZGC2>NH>GC。籽粒平均灌浆速率的大小,在灌浆不同阶段存在一定的差异,灌浆渐增期和快增期均表现为NH>GC>ZGC,而灌浆缓增期则表现为ZGC>NH>GC。灌浆快增期积累的干物质量对产量的贡献率为ZGC2>ZGC1>GC>NH。脱水速率前期表现为NH>GC>ZGC1>ZGC2,授粉后32~60 d的脱水速率为ZGC2>ZGC1>GC>NH,且模式间差异较大。     

Molecular and metabolic changes of cherelle wilt of cacao and its effect on Moniliophthora roreri

Young Theobroma cacao pods, known as cherelles, are commonly lost to physiological thinning known as cherelle wilt. Cherelles are susceptible to frosty pod rot caused by Moniliophthora roreri. We studied the cherelle wilt process and its impact on M. roreri infection using microscopic, metabolite, and gene expression analyses. Wilt was associated with increased levels of tricarboxylic acid cycle intermediaries and decreased levels of major metabolites. Expression changes of cacao ESTs in response to wilt suggest induction of the polyamine, ethylene, and jasmonic acid biosynthetic pathways and regulation of abscisic acid and cytokinin levels. M. roreriinfection caused little alteration of cherelle physiology. M. roreri responded to the late stage of wilt by altering the expression of M. roreri ESTs associated with metabolite detoxification and host tissue degradation. The environment of the wilting cherelles may truncate the disease cycle of frosty pod rot, by limiting M. roreri sporulation and stopping the lifecycle.     

Activity of polygalacturonases from Moniliophthora perniciosa depends on fungus culture conditions and is enhanced by Theobroma cacao extracts

We report the first analysis of polygalacturonase regulation in the basidiomycete Moniliophthora perniciosa. Non-secreted and secreted polygalacturonase activity was obtained from M. perniciosa cultivated on bran-based solid medium or liquid media containing additional carbon sources or cacao extracts (infected or not by the fungus). Polygalacturonase activity assays were carried out under different temperatures and incubation periods. The best secreted polygalacturonase activity was obtained when the enzymatic assay was made at 50 °C for 10 min. Moreover, the polygalacturonase activity was enhanced when the fungus was cultivated on potato dextrose medium, in the presence of additional fermentable carbon sources, in the presence of cacao pulp or non infected cacao extracts.     

花叶芦竹光合特性日动态及其影响因素分析

以生态沟渠花叶芦竹(Arundo donax var. versicolor)为材料,采用便携式CID–340光合仪,在晴朗天气测定花叶芦竹成熟叶片净光合速率(Pn)和光合有效辐射(PAR)、气孔导度(Gs)、胞间CO2浓度(Ci)、叶温(Tl)、叶周围气温(Ta)和蒸腾速率(Tr)等影响因子,对花叶芦竹光合特性日动态及其影响因素进行分析。结果表明：①花叶芦竹叶片净光合速率(Pn)日变化曲线呈单峰型,峰值为19.76 μmol/(m2•s),峰值出现在15:00左右;②逐步回归分析结果表明,净光合速率主要受蒸腾速率、胞间CO2浓度、叶温和气温的影响;③偏相关分析和通径分析结果表明,胞间CO2浓度、蒸腾速率也是影响花叶芦竹净光合速率的主要因子,且胞间CO2浓度的影响比蒸腾速率的影响大。     

茶园物理除虫机除虫效果试验研究

对影响茶园物理除虫机除虫率的出风角度、风速、行走速度分别进行单因素试验和正交试验。单因素试验结果表明,当出风角度为5°、风速18 m/s、行走速度0.7 m/s时,除虫率可达81.5%。正交试验结果表明,对除虫机除虫率影响大小依次为风速、出风角度、行走速度;极差分析的最好组合为出风角度5°、风速18 m/s、行走速度0.9 m/s,除虫率为80.5%。对2个试验结果进行验证对比分析,认为单因素最佳参数组合的除虫效果最好。     

有机生态型无土栽培的基质和施肥技术研究进展

对有机生态型无土栽培基质的材料处理、配制、理化性状、配方筛选、营养和有机生态型无土栽培的施肥技术进行了综述,并对其发展前景进行了展望。