薇甘菊（Mikania micrantha）是一种快速生长的全球性入侵杂草，广泛分布在热带和亚热带地区。薇甘菊的入侵会对当地自然生态系统造成严重破坏，并对森林和作物生产造成巨大的经济损失。它在光合作用方面具有优势，其净光合速率与C₄植物相近，固碳能力较高。研究表明薇甘菊的光合能力是其快速生长和快速殖民新栖息地的重要原因之一。然而，目前尚没有研究揭示薇甘菊光合作用的进化机制和昼夜规律。本研究采用基因组学和转录组学相结合的方法，揭示了薇甘菊光合作用的进化机制和昼夜表达模式。结果显示，在薇甘菊中有16个正选择基因，主要集中于光反应和光同化物的利用两个过程中，并且叶绿素a/b结合蛋白、苹果酸脱氢酶、丙酮酸正磷酸二激酶和苹果酸酶家族的基因数量与C₄植物(高粱或玉米)相似，显著高于其他植物。在不同组织中，98.1%与光反应相关的基因在茎中具有较高表达，C₄循环相关的基因中有一半以上在茎中高于叶中的表达。气孔开闭过程中，2个碳酸酐酶基因在18:00的表达量高于8:00，SLAC1和HT1基因在18:00表达量最低。此外，与光合作用相关的基因在7:00和17:00表达量较高。因此我们推测，薇甘菊能够在茎和花器官中进行光合作用，并且叶片的一些气孔在夜间能够通过CO₂信号打开。此外，它的进化可能会减弱高光强时的光抑制，并在低光强时提高光合作用的效率。组织特异性光合类型和光合相关基因的不同昼夜模式可能有助于薇甘菊在新栖息地的快速定植。薇甘菊可能通过这些变化增加了它的种间优势和侵袭性。本文的研究结果为了解薇甘菊的光合作用机制及其控制和生物利用度提供了有价值的信息。

绒毛膜形成期是昆虫卵子发生的最后阶段，在这一阶段，滤泡细胞通过合成分泌绒毛膜蛋白，转移至发育的卵母细胞表面沉积形成卵壳，为胚胎发育提供保护屏障。目前对绒毛膜基因家族的研究大多集中在模式昆虫，如家蚕和果蝇，在世界性害虫小菜蛾中仍缺少对绒毛膜基因家族的系统鉴定以及其功能分析。因此明确绒毛膜基因家族在小菜蛾基因组上的分布情况及其转录特征，解析绒毛膜基因在小菜蛾卵子发生过程，以及胚胎发育过程中的重要作用，可为小菜蛾的遗传调控提供潜在分子靶标。本研究分析鉴定了小菜蛾绒毛膜基因的数量及染色体定位、分子特征、进化关系及其启动子区的序列特性，基于转录组数据以及qPCR实验，分析了绒毛膜基因在不同龄期和不同组织的表达模式，并基于RNAi揭示了PxCho-1的生殖功能。在小菜蛾中一共鉴定得到15个绒毛膜基因，分为A、B两大类。不同类型绒毛膜基因以成对的方式分布在染色体上。部分绒毛膜基因对，共享一个双向启动子调控区。系统发育分析表明，A、B两类绒毛膜基因具有高度的保守性，并且在对应类别中，小菜蛾绒毛膜基因均具有物种特异性。不同龄期与组织的表达谱与qPCR分析均显示，绒毛膜基因主要在小菜蛾雌成虫中显著高表达，并且在卵黄完全沉积的卵巢内显著高表达，说明绒毛膜基因在小菜蛾雌成虫的生殖发育中具有重要作用，且主要作用于卵子发生后期。抑制PxCho-1基因转录虽然对卵黄沉积没有影响，但会导致卵子变小，孵化率急剧下降，同时导致卵子内卵壳柱状层的排列松弛，以及外卵壳绒毛变短。本研究为探索小菜蛾雌性生殖调控机制奠定了理论基础，有利于筛选潜在的小菜蛾遗传防控分子靶标。

重大农业入侵害虫草地贪夜蛾原产于美洲，自2016年首次被发现入侵尼日利亚和加纳以来，短短3年时间内迅速入侵至47个非洲国家和18个亚洲国家。由于该虫寄主范围广（至少包含353种寄主植物）、能够适应多种生境、超强的迁飞能力、高繁殖力、暴食性，以及快速发展的农药抗性和病毒抗性等内在优势，是导致其具有入侵性的重要原因，目前已被公认为全球范围内的超级害虫。该害虫的综合治理策略主要依靠监测调查、农业防治、化学防治、病毒制剂、性诱剂、生物防治（寄生性天敌、捕食性天敌和昆虫病原体），以及植物源农药等多种防治策略的综合应用。目前尚需要进一步研究的主要内容包括：（1）明确草地贪夜蛾的入侵机制，（2）如何阻止其进一步扩散，（3）提供更有效的防治策略。本文总结了草地贪夜蛾的生物学特性，潜在的入侵性机制，以及综合治理策略，以期为今后的治理提供参考。

Received  10 October, 2017    Accepted  9 February, 2018

Huanglongbing (HLB, or citrus greening) is the most destructive disease of citrus, which is associated with Candidatus Liberibacter asiaticus (Las). Few management options are available, aside from preventive measures such as removing infected plants, planting disease-free seedlings, and managing the insect vector. In this study, we assessed the efficacy of thermotherapy against HLB under controlled greenhouse conditions. A total of 60 two-year-old, graft-infected Citrus reticulata Blanco plants were used. The plants were randomly divided into three groups (45°C, 48°C, and untreated control), with five plants/replicate (rep) and four reps/treatment. The treated plants were placed in phytotrons for a 4-h treatment session, repeated once per week for three consecutive weeks. Disease remission was observed eight weeks post-treatment. Real-time PCR assays revealed that Las titers in HLB-affected seedlings were significantly reduced in both 45 and 48°C treatments four weeks after treatment, with the exception of eight plants. In contrast, Las titers in the untreated control plants increased significantly during the same period, with a maximum increase of 28-fold. Except for seven plants, Las titers in the new flushes of treated plants decreased more than 90% eight weeks after treatment. Las titers in mature leaves of treated plants decreased 56 and 60% in average at 45 and 48°C, respectively, eight weeks after treatment. The HLB symptoms and Las titer of seedings were markedly alleviated eight weeks after treatment in both 45 and 48°C treatments. Our results laid a good foundation for the further development of citrus free-disease seedling cultivation and Huanglongbing control in the field. The whole plants were replaced for scion or branch in previous as the research object in this study, and the expression of Huanglongbing symptoms combined with real-time polymerase chain reaction (PCR) were used to evaluate the effect of heat treatment in the greenhouse.

Wheat leaf rust (caused by Puccinia triticina) is one of the most important fungal diseases in China. There are tens of winter wheat cultivars which are approved to be released by the government at a national level and more than 100 wheat cultivars at the provincial level. But there is no information about leaf rust (Lr) genes in these cultivars, which makes it difficult for farmers and breeders to select which cultivars they should plant in their fields and use in their breeding programs. The objective of this paper was to identify the leaf rust resistant genes at seedling stage present in the 84 commercial wheat cultivars from China that have been released in the past few years. A set of 20 near isogenic lines with Thatcher background and 6 lines with known Lr genes were used to test the virulence of 12 races of P. triticina (Pt). By comparing the infection types (ITs) produced on the 84 cultivars by the 12 Pt races with the ITs on the differential sets, the Lr genes were postulated. In addition, 8 molecular markers of Lr genes such as Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26 and Lr29, which are closely linked to or co-segregated with the Lr gene, were used for further validation of the genes in the 84 Chinese winter wheat cultivars. Twelve Lr genes, including Lr1, Lr3, (Lr3bg), (Lr3ka), Lr11, Lr13, Lr14a, Lr16, Lr26, Lr27, Lr30 and Lr31 were postulated to be present either singly or in combinations in these Chinese wheat cultivars. Lr3 and Lr26 were detected most often in the tested cultivars, with frequencies of 51.2 and 38.1%, respectively. No wheat Lr genes were detected in 16 cultivars, and 4 cultivars may carry unknown Lr genes other than those used in this study. Lr9, Lr20, Lr21, Lr24, Lr25 and Lr29 were not present in any of the 84 tested accessions.

Stem or black rust of wheat, caused by the fungus Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn. (Pgt), has historically caused severe losses to wheat (Triticum aestivum L.) production worldwide. In the Fujian and Guangdong provinces of China, six moderate-to-severe epidemics of wheat stem rust have occurred, which caused destructive losses of wheat between 1949 and 1966, although these were brought under control by integrated management. A rapid and reliable detection of the pathogen will contribute to the accurate forecast and seasonal control of this disease. The objective of this study was to develop a diagnostic molecular marker generated from simple sequence repeats (SSR) for the early rapid identification of P. graminis. The genomic DNA of P. graminis, Puccinia striiformis, Puccinia triticina and seven other species was amplified by a pair of SSR primers generated by the FIASCO (fast isolation by AFLP sequences containing repeats) enrichment protocol. The primer set Pgtw (f)/ Pgtw (r) generated a polymorphic pattern displaying a 330-bp DNA fragment specific for P. graminis whereas no DNA fragment was obtained from other non-target wheat fungal pathogens. The detection limit of the primer was 1 ng DNA in a 25-mL PCR reaction. The SSR markers of P. graminis can also be used to detect the presence of latent hyphae in Pgt-infected wheat leaves as early as 30 h post-inoculation. A rapid approach to distinguish P. graminis from similar pathogenic fungi would be anticipated in further study.

The plasmid pGPDGFP under the control of pgpdA promotor was used together with vector pAN7-1 containing the hygromycin resistance cassette to co-transform protoplasts of HG1, Fusarium graminearum from Hubei Province, China. Twelve out of 14 hygromycin-resistant transformants showed green signal under the UV light and contained one or several copies of gfp, as indicated by Southern analysis of genomic DNA digested with different restriction enzymes and hybridized to the gfp probe. A single gfp copy transformant (HG1C5) was selected for further evaluation of 80 Chinese wheat cultivars or advanced lines. The results showed different resistance type to F. graminearum were observed. GFP signals observed in the rachis and adjacent spikes of 70 Chinese wheat lines such as Chuanchongzu 104 indicated both type I (host resistance to the initial infection by the fungus) and type II (resistance to the spread of FHB symptoms within an infected spike) were not observed. While other 10 lines showed type II resistance to F. graminearum with GFP signals only in inoculated spikelets. Development of the mycelium can be intuitively observed and the resistance of wheat to F. graminearum can be identified at 7 days post inoculation (dpi) in this way. The results showed no differences were evaluated between the transformed HG1C5 and the non-transgene artificial inoculation by SAS paired chi-square test and McNemar’s test (P=0.0625).

To analyze the intrinsic relationship between rhizosphere microbial community structure and variety of rice, the microbial community structures in rhizosphere of different hybrid rice cultivars were determined with phospholipid fatty acids (PLFA) analysis. Three series of new-breeding hybrid rice cultivars in China were tested in the experiment, IIyouming 86 (II-32A/Minghui 86), IIyouhang 1 (II-32A/Hang 1), and IIyouhang 2 (II-32A/Hang 2) with II-32A as female parent, XinyouHK02 (XinA/HK02) and YiyouHK02 (YXA/HK02) with HK02 as male parent, Chuanyou 167 (ChuanxiangA/MR167) and 44you167 (Hunan44A/MR167) with MR167 as male parent. The results showed that the microbial community in rhizosphere of the hybrid rice comprised bacteria, fungi, actinomycetes, and protozoa, according to the 40 PLFA biomarkers detected. Bacteria were more abundant than fungi and actinomycetes in rhizosphere of the hybrid rice tested. Both sulfate-reducing and methane-oxidizing bacteria were found to exist in the hybrid rice rhizosphere. It was also found that the characteristics of PLFA biomarkers had correlation with the biological traits of rice. The cluster analysis suggested that microbial community structure and activity in rhizosphere were associated with genetic background of the rice cultivar.