卷丹百合黑斑病病原鉴定及生物学特性研究

随着卷丹百合种植面积的扩大,卷丹百合叶部真菌性病害也越来越严重,尤其在2014年6~7月份,由于降水偏多,卷丹百合叶部病害大发生,6月中旬重病田卷丹百合枯死株率达50%~70%,部分田块卷丹百合地上部全部枯死。从卷丹百合发病叶片分离得到病原菌,进行致病性鉴定、孢子形态观察、18S rDNA序列分析,生物学特性研究,结果表明,该病原菌为半知菌链格孢（ Alternaria alternata）。该菌菌丝生长致死温度为55℃;适宜 pH为6~7;在供试的几种碳、氮源中,最适的碳源是麦芽糖,最适的氮源是酵母。     

植物组织培养:最新进展和潜在的应用(英文)

植物组织培养体系在基础研究和商业应用中具有巨大的潜能,例如园艺产业。组织培养过程伴随着一系列关于形态学、生理学、生物化学、分子和表观遗传的改变。分子水平的改变主要包括基因突变、DNA重组、染色体变异和表观遗传调控(DNA甲基化、组蛋白修饰、染色质重塑、小RNA调节)。这些改变被认为能促进外植体对培养环境的适应并有益于随后的形态发生。目前,组培已在商业应用和细胞生物学、遗传学、生物化学等基本研究中发挥了重要作用。本文重点介绍了植物组织培养的原理概念、培养基的制作、外植体的选择、各种激素的作用机理、植物离体快速繁殖的3大难题(外植体的污染、褐变、试管苗的玻璃化)以及防止措施,并详细阐述了植物离体快繁、无病毒苗木培育、培养细胞突变体、人工种子和离体培养期间分子水平的变化。     

耐铜菌株TLSB2-K的鉴定及其铜富集能力测定

[目的]研究菌株TLSB2-K的铜耐性以及其铜富集能力的特性.[方法]通过形态观察、革兰氏染色和16S rDNA序列比对,对前期分离的菌株TLSB2-K进行了鉴定,并采用振荡培养法,探讨了温度、pH值和渗透压对菌株生长的影响,以及铜胁迫下菌株对铜的耐性及富集能力.[结果]TLSB2-K属于蜡样芽孢杆菌(Bacillus cereus),最适生长条件为:温度为27℃、pH值为7、渗透压为1.1％ NaC1.铜浓度100～500 mg/L范围内,菌体生长良好,铜浓度在100～400 mg/L范围内,菌体铜含量随着铜浓度的升高而增加,当铜浓度400 mg/L胁迫培养30 h,菌体铜含量达到最大值2 250mg/kg;菌株的最高铜耐受浓度为700 mg/L.[结论]菌株TLSB2-K具有较强的铜耐性和较高的铜富集能力,具有重要的理论研究和工程应用价值.     

ISSR-Based Molecular Characterization of an Elite Germplasm Collection of Sweet Potato （Ipomoea batatas L.） in China

To determine the genetic diversity and population structure of sweet potato accessions cultivated in China, and to establish the genetic relationships among their germplasm types, a representative collection of 240 accessions was analyzed using inter-simple sequence repeat （ISSR） markers. The mean genetic similarity coefifcient, Nei’s gene diversity, and shared allele distance of tested sweet potato accessions were 0.7302, 0.3167 and 0.2698, respectively. The 240 accessions could be divided into six subgroups and ifve subpopulations based on neighbor-joining （NJ） clustering and STRUCTURE results, and obvious genetic relationships among the tested sweet potato accessions were identiifed. The marker-based NJ clustering and population structure showed no distinct assignment pattern corresponding to lfesh color or geographical ecotype of the tested sweet potato germplasm. Analysis of molecular variance （AMOVA） revealed small but signiifcant difference between white and orange-lfeshed sweet potato accessions. Small but signiifcant difference were also observed among sweet potato accessions from the Southern summer-autumn sweet potato region, the Yellow River Basin spring and summer sweet potato region and the Yangtze River Basin summer sweet potato region. This study demonstrates that genetic diversity in the tested sweet potato germplasm collection in China is lower than that in some reported sweet potato germplasm collections from other regions. Pedigree investigations suggest that more diverse Chinese sweet potato varieties should be formed by broadening the selection scope of breeding parents and incorporating the introduced varieties into future breeding programs.     

Molecular Mapping of a Stripe Rust Resistance Gene YrH9020a Transferred from Psathyrostachys huashanica Keng on Wheat Chromosome 6D

Stripe rust （yellow rust）, caused by Puccinia striiformis f. sp. tritici （Pst）, is one of the most devastating diseases of wheat throughout the world. H9020-1-6-8-3 is a translocation line originally developed from interspeciifc hybridization between wheat line 7182 and Psathyrostachys huashanica Keng and is resistant to most Pst races in China. To identify the resistance gene（s） in the translocation line, H9020-1-6-8-3 was crossed with susceptible cultivar Mingxian 169, and seedlings of the parents, F1, F2, F3, and BC1 generations were tested with prevalent Chinese Pst race CYR32 under controlled greenhouse conditions. The results indicated that there is a single dominant gene, temporarily designated as YrH9020a, conferring resistance to CYR32. The resistance gene was mapped by the F2 population from Mingxian 169/H9020-1-6-8-3. It was linked to six microsatellite markers, including Xbarc196, Xbarc202, Xbarc96, Xgpw4372, Xbarc21, and Xgdm141, lfanked by Xbarc96 and Xbarc202 with at 4.5 and 8.3 cM, respectively. Based on the chromosomal locations of these markers and the test of Chinese Spring （CS） nullitetrasomic and ditelosomic lines, the gene was assigned to chromosome 6D. According to the origin and the chromosomal location, YrH9020a might be a new resistance gene to stripe rust. The lfanking markers linked to YrH9020a could be useful for marker-assisted selection in breeding programs.     

道地产区不同牛膝种群的遗传多样性分析

【目的】对道地产区河南8个野生牛膝种群叶绿体基因psbA-trnH序列的变化进行分析,研究牛膝种群的遗传多样性,为牛膝野生种群的保护提供依据。【方法】选取河南8个野生牛膝种群(信阳鸡公山种群、信阳灵山种群、南阳淮源种群、南阳大乘山种群、洛阳龙峪湾种群、南阳老界岭种群、新乡九莲山种群、新乡万仙山种群)为材料,PCR扩增其叶绿体多态性片段psbA-trnH,分析其在供试8个牛膝野生种群中的差异,并据此分析各种群的遗传多样性。【结果】从8个牛膝种群的叶绿体片段中得到6个单倍型(Ⅰ~Ⅵ),其中单倍型Ⅰ为祖先单倍型,与其他单倍型仅差1个突变步。牛膝单倍型多样性指数为0.594,核苷酸多样性指数为2.13×10-3。牛膝种群遗传距离与地理距离之间不存在正相关关系。淮源种群的遗传多样性最高,且有特殊的基因型Ⅱ和Ⅴ;九莲山种群具有特殊的基因型Ⅵ。【结论】道地产区河南野生牛膝种群的遗传多样性相对较低;淮源种群与九莲山种群应该作为保护单元受到更多的重视。     

分子生物学教学改革探究

针对六盘水师范学院分子生物学教学存在的问题,结合教学实践,从理论课教学改革和实验课教学改革两方面对该课程进行了阐述,以期在今后分子生物学课程的教学过程中取得更好的效果。     

转基因技术在玉米育种中的运用

就玉米转基因在抗除草剂、抗虫、抗病、抗盐碱等方面取得的成果进行了回顾,以期为我国玉米分子育种研究提供参考。     

稻飞虱翅型分化的研究进展

翅二型现象存在于褐飞虱(Nilaparvata lugens)、灰飞虱(Laodelphax striatellus)和白背飞虱(Sogatella furcifera)等稻飞虱种群中.综述了遗传等内在因素以及外部因素(温度、相对湿度、光周期、寄主等)对3种稻飞虱长、短翅型分化的影响,探讨了各因素对稻飞虱翅型分化的作用机制,讨论了稻飞虱翅型分化研究中存在的问题,并对制定与稻飞虱翅型分化相关的害虫控制策略提出了建议.     

植物高温抗性转录因子基因工程研究进展

高温胁迫是影响植物生长代谢和产量的重要因素之一,通过基因工程方法能提高植物抵御热胁迫的能力。现对近年来发现的与植物高温抗性有关的转录因子进行综述,并阐述了通过基因工程方法利用已知转录因子提高植物抗热性的研究进展,以期为利用基因工程方法培育抗热植物提供参考。