设施杏抗风险栽培研究

设施杏效益高、发展快,但近年的生产现状表明达到丰产要求的设施杏很少.依据各生产因素对设施杏的影响不同,划分为"致死因素"、"非致死因素"、"偶然因素"和"非风险因素"几方面,总结历年生产经验和研究成果,制定了科学的设施杏抗风险栽培的技术规程,为果农生产操作提供借鉴.     

Cloning of Thymidine Kinase Gene of Duck Plague Virus Using Degenerate PCR

The DNA of duck plague virus （DPV） thymidine kinase （TK） gene was cloned and sequenced from a vaccine virus in the study. Degenerate oligonucleotide primers for the consensus site of herpesvirus UL24, TK, and glycoprotein H（gH） gene were used in the polymerase chain reaction （PCR） to amplify DNA product with 3 741-base-pairs （bp） in size. DNA sequence analysis revealed a 1 077-base-pairs （bp） open reading frame （ORF） encoding a 358 amino acid polypeptide homologous to herpesvirus TK proteins. The predicted TK protein shared 31.2, 41.3, 35.7, 37.4, and 28.4% identity with herpes simplex virus typel, equine herpesvirus type 4, Marek＇s disease virus 2, herpesvirus turkey, and infectious laryngotracheitis virus, respectively. Comparison of the amino acid sequences of other herpesvirus TK proteins showed that these proteins were not conserved on the whole, otherwise the portion of the TK proteins corresponding to the nucleotide binding domain and the nucleoside binding site were highly conserved among herpesvirus. Comparison with the amino acid sequences of the conserved nucleotide and nucleoside binding domains of other eleven herpesvirus TK proteins to the predicted DPV peptide confirmed its identity as the DPV TK protein.     

凉山人工草地退化原因及治理研究

虽然人工草地在凉山大面积种植,由于利用不合理,正在逐年退化。本文介绍了人工草地退化原因,阐述了治理措施。     

青藏高原退化高寒草甸草原分类的遥感研究

应用遥感技术,探讨了青藏高原巴颜喀拉山北坡,青海省达回县段退化高寒草甸草原的类型、分布、面积和遥感判译标志。将研究区内高寒草甸划分为五个类,两个亚类和三个退化草原型。重点分析了高山草甸草原退化的主要原因和遥感影像特征。研究结果表明,青藏高原高寒草甸牧业区,局部草甸载畜能力与局部草甸成土母质的理化特性密切相关。制定科学合理的放牧载畜量应考虑成土母质因素。     

简并引物设计与大戟科3种植物WAX基因片段的克隆

在大戟科3种重要经济植物木薯、蓖麻、小桐子中,扩增WAX基因片段。利用CODEHOP方法设计简并引物,同时在3种植物中提取高质量的总RNA并反转录为cDNA,结果扩增在3种植物中得到特异性片段,克隆测序,并采用生物信息学技术进行序列分析。结果证明CODEHOP简并引物设计科学。同时证明WAX基因的保守性较高,在大戟科3个物种中同时得到了WAX基因片段序列信息,具有较高同源性。为以后WAX基因研究奠定重要基础。     

简并引物的程序化设计与荔枝HMGR基因片段的克隆

主要介绍了利用NCBI、DDBJ、Blockmaker、CodeHop和Oligo6.0等数据库和生物软件进行简并引物设计的方法。利用设计的6对简并引物进行RT-PCR,从荔枝(LitchichinensisSonn.)果实中克隆到2个长度分别为510bp和582bp的cDNA片段。通过Blastx检索Genbank进行同源性比对后,发现2片段都与其它植物的HMGR基因具有较高的氨基酸序列同源性。研究表明,该程序化设计的简并引物可信性强,阳性率高,能迅速得到满意结果。     

Application of degenerate oligonucleotide primed PCR (DOP-PCR) for SNP discovery in soybean

As the majority of methods for single nucleotide polymorphism (SNP) identification are highly cost-prohibitive, it is necessary to develop new strategies that are more suitable for small and medium-scale laboratories. In this paper, we investigate the potential of degenerate oligonucleotide primed PCR (DOP-PCR) for SNP discovery in soybean. PCR fragments were amplified from two soybean cultivars, ‘Pureunkong’ and ‘Jinpumkong 2,’ shotgun cloned and sequenced. The sequences of both cultivars were then assembled and examined for occurrence of SNPs. The effectiveness of SNP discovery was much lower than expected. Over 1,300 analyzed sequences were grouped in 144 contigs, but only 51 putative SNP sites were found in 18 of these contigs. About 50% of the contigs contained identical sequences and in more than one-third (35.4%), putative paralogous fragments were assembled. Subsequent validation of SNPs allowed the confirmation of only eight SNP sites. The failure to validate the remaining SNPs was mostly due to amplification of duplicated or multiplicated genomic regions. A relatively high proportion of chloroplast and mitochondrial DNA sequences was another limitation of effective SNP detection. Although the DOP-PCR technique was not efficient enough for SNP discovery because of the degree of soybean genome complication, the relatively large number of paralogous sequences in our data collection can be used for further detailed analysis of the genome structure of this species.     

油菜野芥细胞质雄性不育恢复基因候选片段的克隆

根据植物细胞质雄性不育恢复基因编码的PPR（pentatricopeptide repeat）蛋白的特点,结合拟南芥PPR基因簇相似序列,扩增油菜野芥细胞质雄性不育(Nsa CMS) 基因组DNA,筛选出一对简并引物,在Nsa不育系育性恢复后的可育材料和野芥亲本中可以同时扩增出符合预期的片段。片段长度为309bp,与萝卜CMS恢复基因核苷酸序列的一致性为69%,与拟南芥1号染色体臂上PPR基因簇核苷酸序列的一致性大于70%,与含波里马（Pol）CMS恢复基因的白菜型油菜相关序列一致性达85%。该片段编码的氨基酸序列含有两个相邻排列的PPR基序,可作为Nsa CMS育性恢复基因的候选片段。     

栽培甜菜助细胞退化进程的超微结构观察

应用透射电镜技术研究栽培甜菜(Beta vulgaris)助细胞退化进程的超微结构特征, 以丰富被子植物生殖生物学资料。结果表明：花蕾时期,2个助细胞相似,珠孔端具发达的丝状器,合点端无壁,极性明显,细胞器种类多,数量大,呈现较强代谢活性;随后,一个助细胞的核质和胞质的电子密度显著高于另一个助细胞,液泡膜消失,线粒体、质体膜与核膜不清晰,细胞出现退化迹象,但内质网和高尔基体丰富,分泌活动旺盛;待花蕾刚开放(授粉前),此助细胞完全退化。另一个助细胞(宿存助细胞)内的细胞器逐渐增多,且功能状态趋于活跃,表现为核糖体、线粒体、质体等数量增加;线粒体内嵴丰富,可见DNA纤丝;质体形态多样,片层明显,内含淀粉粒。至卵细胞受精前(授粉后约13 h),宿存助细胞代谢达到最活跃状态;至合子合点端建成蜂窝状细胞壁且胚乳游离核形成后,宿存助细胞开始退化;至合子后期,此细胞退化完全,丝状器消失。上述结果表明,栽培甜菜助细胞的退化与授粉和花粉管生长无关;宿存助细胞做为传递细胞,为胚囊的发育吸收并转输营养。     

TAIL-PCR技术分离柞蚕丝素基因3′端非编码区未知DNA序列

以柞蚕基因组DNA为材料,采用热不对称交错PCR(TAIL-PCR)技术分离出1 998 bp的DNA序列。将该序列与Genebank上的柞蚕丝素基因DNA序列(AF083334)进行比较分析结果表明,新钓取的DNA片断中1 758 bp的DNA序列为柞蚕丝素基因3′端非编码区未知DNA序列。TAIL-PCR技术为柞蚕丝素基因3′端非编码区未知DNA序列的钓取提供了一种简便、高效的方法。