茄病镰刀菌单克隆抗体的制备及胶体金免疫层析试纸条的研发*

Objective: The cell lines secreting specific monoclonal antibodies (McAbs) were prepared by using Fusarium solani, one of the pathogenic fungi causing root rot of Fritillaria thunbergii, and the colloidal gold immunochromatographic test strip based on McAbs was developed to provide scientific basis for detecting root rot of F. thunbergii. Methods: Hybridoma technology was used to obtain cell lines that could secrete specific McAbs against F. solani using the whole protein extract of F. solani as the antigen. The specificity, titer, sensitivity and binding protein of McAbs were detected by indirect ELISA and Western blot. Colloidal gold particles were prepared by trisodium citrate reduction method and McAbs were labeled to prepare colloidal gold immunochromatographic strip. Results: Three cell lines secreting specific McAbs against F. solani were obtained, which were named as FsA3, FsG6 and FsD4. The detection sensitivity of FsA3 was 24.41 ng / mL, and that of both FsG6 and FsD4 was 12.21 ng / mL. FsA3, FsG6 and FsD4 had strong reactions to F. solani, and had no cross-reaction to Alternaria tenuissima, A. alternata, Botrytis cinerea, F. equiseti, F. incarnatum, F. oxysporum, Phoma sp., and Phomopsis oblonga. The colloidal gold immunochromatographic strip based on FsG6 showed only a quality control line when detecting the tissue culture seedlings of F. thunbergii. When 100 ng F. solani antigen or the samples of F. thunbergii infested with root rot disease were detected, there were visible quality control lines and test lines. Conclusion: The specificity and sensitivity of the McAbs and test strip are sufficient to detect F. solani isolated from diseased strains of F. thunbergii, which provides the technical support for the rapid detection of root rot of F. thunbergii in the field.     

基于图形硬件加速的生物序列比对算法研究

生物序列比对是生物信息学的基础,是当今功能基因组学研究中最常用、最重要的研究方法之一。本文对各类序列比对算法优缺点进行分析,对图形硬件的优势进行挖掘。在此基础上,将各类序列比对算法中准确性最高的动态规划算法予以实现,并将其映射到图形硬件上,以实现算法加速。通过实例进行性能评测,结果表明该加速算法在保证比对准确性的同时,能较大地提高比对速度。     

蚕沙发酵肥在制作过程中的微生物结构变化

目的比较蚕沙发酵肥在发酵前后的微生物结构变化,阐明蚕沙发酵肥的微生物多样性。方法蚕沙发酵肥由基底土和蚕沙按一定比例混合后发酵30d而来,因此实验共分为4个处理组,分别为基底土组、蚕沙组、蚕沙发酵肥30d组和蚕沙发酵肥90d组。分别采集基底土、蚕沙以及发酵30d后的蚕沙发酵肥进行MiSeq高通量测序,比较蚕沙发酵肥与发酵前的基底土、蚕沙之间的细菌多样性变化,并采集发酵90d的蚕沙发酵肥进行测序,比较不同发酵时间对发酵肥细菌多样性的影响。结果蚕沙发酵肥30d组的细菌多样性指数最高,蚕沙最低,说明蚕沙在与基底土混合发酵后细菌多样性水平升高。β多样性结果显示蚕沙发酵肥的稳定性好,且发酵肥与蚕沙的近缘关系较与土壤的更近。比较优势菌属发现,蚕沙发酵肥30d组有10种优势菌属,分别为Sphingobacterium、Parapedobacter、Ochrobactrum、Flavobacterium、Bordetella、Brucella、Rhizobium、Olivibacter、Devosia和Paracoccus;发酵肥90d组中的优势菌属有70%与30d组相同;蚕沙组中仅有5种优势菌属,分别为Parapedobacter、Bacillus、Pseudomonas、Flavobacterium和Sphingobacterium,其中Parapedobacter、Flavobacterium和Sphingobacterium也为发酵肥30d组的优势菌属;基底土的优势菌属大部分为酸杆菌门,分别为Gp1、Gp2、Gp3、Bradyrhizobium、Rhizomicrobium和Rhodoplanes,它们在经发酵后含量大大下降。蚕沙发酵肥中的大部分优势菌属均为具有生防作用的生防菌,其中部分优势菌属也存在于施用了发酵肥的连作白菊根际土中。结论蚕沙与基底土混和发酵制成蚕沙发酵肥后细菌多样性发生显著变化,生防菌种类显著增加,同时蚕沙发酵肥中的这些生防菌来源于蚕沙并非基底土。蚕沙发酵肥缓解连作障碍的机制之一可能是由于蚕沙发酵肥中存在的大量生防菌。