超表达OsSsr1基因增强烟草耐盐性

本研究从水稻品种R109中克隆了OsSsr1基因（GenBank Accession No.NM₀01065574）,并用土壤根癌杆菌介导的方法,把OsSsr1基因转入本氏烟（Nicotiana benthamiana）中,提高了转基因植株的耐盐性。生理指标测定结果表明:在盐胁迫下,转基因和野生型植株中的丙二醛（MDA）、脯氨酸的含量以及过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性都呈上升趋势,但转基因烟草中MDA含量升高速率明显低于野生型,而脯氨酸的含量以及POD、SOD活性的升高速率明显高于野生型烟草。因此,OsSsr1转基因烟草耐盐性的增强,可能是脯氨酸含量和活性氧清除能力的提高引起的。     

Physiology and defense responses of wheat to the infestation of different cereal aphids

Cereal aphids are major insect pests of wheat, which cause significant damages to wheat production. Previous studies mainly focused on the resistance of different wheat varieties to one specific aphid species. However, reports on the physiology and defense responses of wheat to different cereal aphids are basically lacking. In this work, we studied the feeding behavior of three cereal aphids: the grain aphid, Sitobion avenae(Fabricius), the greenbugs, Schizaphis graminum(Rondani), and the bird cherry-oat aphid, Rhopalosiphum padi(Linnaeus) on winter wheat, and the physiology and defense responses of wheat to the infestation of these cereal aphids with focus on how these cereal aphids utilize divergent strategies to optimize their nutrition requirement from wheat leaves. Our results indicated that S. graminum and R. padi were better adapted to penetrating phloem tissue and to collect more nutrition than S. avenae. The harm on wheat physiology committed by S. graminum and R. padi was severer than that by S. avenae, through reducing chlorophyll concentration and interfering metabolism genes. Furthermore, cereal aphids manipulated the plant nutrition metabolism by increasing the relative concentration of major amino acids and percentage of essential amino acids. In addition, different cereal aphids triggered specific defense response in wheat. All of these results suggested that different cereal aphids utilize divergent strategies to change the physiological and defense responses of their host plants in order to optimize their nutrition absorption and requirement. These findings not only extend our current knowledge on the insect–plant interactions but also provide useful clues to develop novel biotechnological strategies for enhancing the resistance and tolerance of crop plants against phloem-feeding insects.     

丁香假单胞大豆致病变种harpin编码基因的克隆表达与功能研究

采用PCR方法从丁香假单胞大豆致病变种(Pseudomonas syringae pv.glycinea)A1和S1菌株中分别克隆到大小为1 026和1 038 bp的hrpZ基因(hrpZPsgA1和hrpZPsgS1),对该基因进行了原核表达和功能研究。SDS-PAGE显示其表达产物为相对分子质量62×103的融合蛋白,harpinZPsgA1和harpinZPsgS1的相对分子质量约为35×103。harpinZPsgS1的粗提蛋白经GSTrap FF纯化后质量浓度可达1.1 mg.mL-1。生物活性检测表明,该蛋白对热稳定,对蛋白酶K敏感,可以在非寄主植物烟草上激发过敏反应,过敏反应可以被真核生物代谢抑制剂抑制,并且对烟草有明显的促生作用。序列比对发现,来自丁香假单胞大豆致病变种的hrpZ基因可分为2类,一类以hrpZPsgA1为代表,包括hrpZPsg12,另一类以hrpZPsgS1为代表,包括来自r0和Race4菌株的hrpZ基因。这2类hrpZ基因的核苷酸同源性为79%,氨基酸同源性为77%,均富含甘氨酸,不含半胱氨酸,与假单胞菌属以外的其他革兰氏阴性植物病原细菌harpin编码基因不存在相似性。     

Metabolite accumulation in strawberry (Fragaria × ananassa Duch.) fruits and runners in response to Colletotrichum nymphaeae infection

The composition of non-infected and Colletotrichum nymphaeae infected strawberry fruits (cultivar ‘Asia') in three different stages of ripeness were evaluated. Additionally, the effect of infection on strawberry runners was monitored. C. nymphaeae infection caused a significant increase in total sugar content in mature fruits (1.1 fold) and a decrease in total sugar content in semi-mature fruits (1.4 fold) and organic acid content in all stages of ripeness (1.7 fold). Ellagic acid derivatives (1.9 fold), flavanols (1.5 fold) and flavonols (5.1 fold) significantly increased during all stages of ripeness after infection. The pattern of phenolic accumulation in strawberry runners was altered by C. nymphaeae infection in contrast to strawberry fruits as most of identified phenols decreased as a response to the infection.     

湖北省葡萄主产区灰葡萄孢菌多样性分析

【目的】了解湖北省葡萄主产区灰葡萄孢菌(Botrytis cinerea)多样性,为葡萄灰霉病防治提供科学依据。【方法】采用常规微生物分离法对从湖北省8个葡萄主产区采集的葡萄灰霉病样本进行灰葡萄孢菌分离,在PDA培养基上观察分离物菌落培养形态并测定菌丝生长速率;利用特异引物对各分离物的Flipper和Boty转座子片段进行扩增,区分转座子类型;扩增Bc-hch基因并用Hha I酶切检测分离物的多态性以区分组群;依据菌丝生长速率、菌落形态及转座子类型挑选4株典型分离物在4个葡萄品种果实上进行致病力测定。【结果】从病害样本中共分离获得51株分离物,菌落培养形态表明30株分离物为菌核型,20株为孢子型,仅1株为菌丝型,出现频率分别为58.82%、39.22%和1.96%。所有分离物菌丝生长速率均较高,在10.86~13.94 mm/d。分离物只存在2种转座子类型,其中50株为Transposa型,仅1株为Flipper型。Bc-hch基因Hha I酶切多态性鉴定结果表明,所有菌株均为Group II,为狭义的灰葡萄孢菌。分离物致病力测定结果表明,菌丝生长速率最低的WH3在供试葡萄品种上的致病力均最强,其次是Flipper型分离物SX1,菌丝生长速率最高的XN2和菌丝型WH6分离物致病力均较弱,且不同分离物在不同品种上致病力趋势不同。【结论】湖北省葡萄主产区灰葡萄孢菌菌落培养形态较丰富,所有分离物均为狭义灰葡萄孢菌,只存在Transposa和Flipper 2种转座子类型,前者占绝对优势,典型分离物间致病力差异明显。     

青霉素影响甜菜夜蛾幼虫耐受几种苏云金杆菌晶体蛋白的能力

本文评估了Cry1Ab、Cry1Ba和Cry1Ca蛋白对甜菜夜蛾2龄幼虫的毒力,其LC50分别为0.442 5、0.675 7 μg/cm2和0.150 2 μg/cm2,Cry1Ba毒力最低,其次是Cry1Ab,而Cry1Ca毒力最高。青霉素影响幼虫对晶体毒素的耐受能力;一次添加高剂量(500 μg/cm2)青霉素于饲料中显著提高幼虫的耐受能力,以含低剂量(60 μg/cm2)青霉素的饲料饲养幼虫多代也能达到相似的效果。     

营养和寄主密度对斑痣悬茧蜂搜寻行为的影响

以斜纹夜蛾Spodoptera litura幼虫为寄主,观察了不同补充营养处理（饥饿、饲喂清水、饲喂30%糖水）和寄主密度等因素对斑痣悬茧蜂Meteorus pulchricornis的搜寻效率和寄生选择行为的影响。结果显示,不同寄主密度对斑痣悬茧蜂的搜寻效率和选择偏好有显著影响,寄生蜂明显倾向于选择高密度寄主斑块。未发现补充营养显著影响斑痣悬茧蜂的搜寻时间,说明补充营养对斑痣悬茧蜂的搜寻效率没有显著影响,但对其寄生的寄主数量具有显著影响,在5头.叶-1与15头.叶-1的寄主斑块之间具有显著差异。     

我国农作物病虫害智能监测预警技术新进展

近年来, 随着计算机、互联网、物联网、人工智能、传感器、遥感等技术的快速发展, 智能虫情测报灯、智能性诱捕器、昆虫雷达、无人机遥感、卫星遥感、智能识别App等现代智能农作物病虫监测装备及重大病虫害实时智能监测预警系统建设方面取得了比较明显的进步。本文综述了我国近5年在利用光谱遥感、昆虫雷达、图像识别等技术进行农作物病虫害监测预警研究和应用方面取得的重要进展, 分析了各类技术存在的不足与难点, 提出了未来发展的方向, 以期为充分利用空天地多源数据实现农作物病虫害精准预报提供指导。     

Bacterial Community in Different Populations of Rice Brown Planthopper Nilaparvata lugens(Stl)

The structures of bacterial communities in the brown planthopper (BPH) Nilaparvata lugens (Stål) from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electrophoresis (DGGE). Results showed that the bacterial communities in BPH nymph from the first to the fifth instars varied with nymphal growth and development. The bacterial communities in the first-instar BPH nymph were similar to those in adults. Nine geographic BPH populations were divided into three groups based on the cluster analysis of DGGE fingerprint. The first group was from the Philippines; the second group was from Thailand and Hainan, Yunnan and Zhejiang provinces of China; and the third group was from Vietnam and Guangxi, Hunan and Jiangxi provinces of China. BPH populations adapted to different resistant rice varieties. The BPH populations from Mudgo (with resistant gene Bph1) and ASD7 (with resistant gene bph2) differed with those of the susceptible rice variety TN1.