中国东部假俭草种质资源多样性初步研究Ⅳ--同工酶分析

利用聚丙烯酰胺垂直凝胶电泳技术,对中国东部地区16份代表性假俭草种质资源两种同工酶进行了测定。结果表明,种源间过氧化物酶和酯酶同工酶酶谱在酶带数目、相对迁移率上均不尽相同,呈现出较丰富的多样性。     

中国假俭草结实性的比较分析

本文以中国有代表性的58份假俭草[Eremochloa ophiuroides(Munro)Hack．]种源为试验材料,以假俭草品种‘Common’和‘TifBlair’为对照,对中国假俭草的种子产量及其组分进行了统计分析。结果表明：中国假俭草种子产量平均为15．1g／m^2,花序密度平均为1510个／m^2,平均结实率为54．4％,平均百粒重0．086g,单位花序小花数平均为20．2。各组分变异系数从大到小依次为：花序密度、结实率、百粒重和单位花序小花数。假俭草种子产量高低主要由花序密度决定,结实率和百粒重也对种子产量有一定的作用,而单位花序小花数对种子产量贡献很小。不同种源种子产量存在显著性差异,产自重庆渝北的E092种源种子产量极显著高于品种‘Common’、“TifBlair’及其他种源;有14份种源的种子产量在24．8—39．5g／m^2范围内,均高于品种‘Common’,但均未达到显著水平;有17份种源的种子产量高于品种“TifBlair”,但也均未达到显著水平。     

中国野生假俭草的研究现状

对近年来我国野生假俭草的研究现状进行了综述,并提出了我国野生假俭草发展前景及今后科研的方向。     

假俭草(Eremochloa ophiuroides (Munro.)Hack.)种质资源改良研究进展

假俭草(Eremochloa ophiuroides (Munro.)Hack.)是主产于中国的世界著名的暖季型草坪草。全面系统地研究假俭草在遗传多样性和抗性生理等各方面的变异变化规律对于开发利用假俭草种质资源具有十分重要的意义。在综述假俭草种质资源的收集、整理和初步评价的基础上,重点介绍了近年来国内外在其遗传多样性(包括形态水平、细胞水平和分子水平)、抗性生理、育种进程和栽培管理措施等方面的研究进展。     

假俭草(Eremochloa ophiuroides(Munro.)Hack.)种质资源改良研究进展

假俭草(Eremochloa ophiuroides(Munro.)Hack.)是主产于中国的世界著名的暖季型草坪草.全面系统地研究假俭草在遗传多样性和抗性生理等各方面的变异变化规律对于开发利用假俭草种质资源具有十分重要的意义.在综述假俭草种质资源的收集、整理和初步评价的基础上,重点介绍了近年来国内外在其遗传多样性(包括形态水平、细胞水平和分子水平)、抗性生理、育种进程和栽培管理措施等方面的研究进展.     

假俭草的组织培养与植株再生

1植物名称假俭草(Eremochloa ophiuroides),又名百足草. 2材料类别成熟种子. 3培养条件(1)诱导愈伤组织培养基:MS 6-BA Q1mg·L-1(单位下同) 2,4-D 4.5.(2)继代培养基:MS 6-BA 0.1 2,4-D 4.0 Vc 5.0.(3)芽分化培养基:MS 6-BA 2.0 NAA1.0 CoCl25.0 TDZ 0.5.(4)生根培养基:1/2MS NAA 0.5 IAA 0.5 MET 0.5 活性炭0.1%.     

假俭草和结缕草营养器官结构对抗逆性的影响

利用光学显微镜和电镜技术;采用石蜡切片法;叶片离析法等实验技术对假俭草和结缕草的茎;叶等营养器官的解剖结构特征和表皮微形态特征作了研究;通过角质层厚度;维管束数目;气孔指数;泡状细胞等数据分析它们之间的抗逆性差别;首次从微形态角度初步了解假俭草和结缕草及其不同种群之间抗旱力;耐践踏性差异的原因。     

钾肥对假俭草草坪种群形成的影响

以四川峨眉山野生假俭草(Eremochloa ophiuroides L.)为实验材料,施以不同浓度的K肥(1.0～2.5g*m-2K2O),观察草坪种群形成过程.结果表明,1.0和 1.5 g*m-2K2O处理组假俭草的生长速度与对照差异显著(P< 0.05); 1.0, 1.5和 2.0 g*m-2 K2O处理组的平均分蘖数与对照的差异达极显著水平(P<0.01); 1.5 g*m-2K2O处理组根系长度与对照差异达显著水平(P<0.05);4 个处理组的根冠比分别比对照增加了 35.61%、50.61%、 21.91%和20.90%. 其中1.5 g*m-2 K2O处理组与对照差异达显著水平(P<0.05).低浓度处理(1.0和1.5 g*m-2 K2O)使草坪成坪时间提前3～5 d.钾对假俭草草坪种群形成有影响,适宜施用量为1.0～1.5 g*m-2 2O.钾肥主要在施用1～3周内起作用,5～10 d肥效高,而后逐渐减弱.     

不同光照条件下假俭草生长格局的分形研究

应用分形几何的原理和方法,研究不同光照条件下假俭草的生长格局。结果表明,假俭草具有自相似性的生长过程。不同光照条件下,假俭草具有不同的分形维数和相应的生物量积累规律。生物量积累速率随着分形维数的增大而增大。分形维数同时反映了假俭草的分枝能力和对空间的占据能力。假俭草种群具有依据外界条件而调节生长格局的生态适应能力。     

用5种同工酶分析云南芋种质资源的遗传多样性

用5种同工酶(酯酶、过氧化物酶、超氧化物歧化酶、多酚氧化酶、细胞色素氧化酶)分析云南48份芋材料遗传多样性,并将5种同工酶的酶带检测结果进行聚类分析.结果表明:48份材料的5种同工酶的酶带数分别在11～19条之间,除超氧化物歧化酶仅有3种酶谱类型外,其余4种同工酶的酶谱数均超过检测试材的半数.将聚类结果与试材的植物学性状相比较,发现以来源、用途、生态位和叶柄、叶心颜色等能对聚类结果进行初步分类,并给予合理解释.因此从试材的植物学性状观察、野生和半野生种的存在以及蛋白质表达水平的同工酶分析结果来看,云南省的芋种质资源呈现丰富的遗传多样性.这为芋遗传变异的进一步深入研究以及对正面临巨大威胁的云南芋资源进行原生境保存的可能性提供了依据.     

Development of an embryogenic callus induction method for centipede grass (<Emphasis Type="Italic">Eremochloa ophiuroides</Emphasis> Munro) and subsequent plant regeneration

The present study demonstrates the establishment of embryogenic tissue from seeds and (seedling-derived hypocotyls) shoot base explants derived from seedlings of Eremochloa ophiuroides. The highest percentage of callus induction obtained from seed and young shoot base explants was 52.0% and 66.6% on Murashige and Skoog (MS) basal media supplemented with 9.0 μM and 18.1 μM 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. The type of callus obtained from both types of explants was off-white to yellow in color and non-friable and shiny in texture. Excised callus from the explants was subcultured onto fresh media of the same recipe for further proliferation. After 10–12 d of subculture, a yellow, globular, friable embryogenic callus was obtained from the initial callus. The highest percentage of embryogenic calli obtained at 40.0% was observed on media containing 2.2 μM 2,4-D. The highest regeneration rate of 46.6% was observed on MS media supplemented with 0.4 μM 2,4-D and 2.2 μM benzylaminopurine (BA). Regenerated shoots were rooted in MS basal medium. Plants with well-developed roots were transferred to pots containing a soil mix and acclimatized in greenhouse conditions. Four weeks post-transfer, acclimatized plants showed 100% survival and remained healthy and green. This is the first report of a successful method for induction of somatic embryogenesis with subsequent plant regeneration in centipede grass and demonstrates the establishment of embryogenic callus and efficient plant regeneration with potential application in the development of genetic transformation systems for centipede grass.     

Assessment of genetic diversity in indigenous turmeric (Curcuma longa) germplasm from India using molecular markers

Curcuma longa L., commonly known as turmeric, is one of the economically and medicinally important plant species. It is predominantly cultivated in the tropical and sub tropical countries. India is the largest producer, and exporter of turmeric in the world, followed by China, Indonesia, Bangladesh and Thailand. In the present study, Directed Amplification of Minisatellite DNA (DAMD) and Inter Simple Sequence Repeats (ISSR), methods were used to estimate the genetic variability in indigenous turmeric germplasm. Cumulative data analysis for DAMD (15) and ISSR (13) markers resulted into 478 fragments, out of which 392 fragments were polymorphic, revealing 82 % polymorphism across the turmeric genotypes. Wide range of pairwise genetic distances (0.03–0.59) across the genotypes revealed that these genotypes are genetically quite diverse. The UPGMA dendrogram generated using cumulative data showed significant relationships amongst the genotypes. All 29 genotypes studied grouped into two clusters irrespective of their geographical affiliations with 100 % bootstrap value except few genotypes, suggesting considerable diversity amongst the genotypes. These results suggested that the current collection of turmeric genotypes preserve the vast majority of natural variations. The results further demonstrate the efficiency and reliability of DAMD and ISSR markers in determining the genetic diversity and relationships among the indigenous turmeric germplasm. DAMD and ISSR profiling have identified diverse turmeric genotypes, which could be further utilized in various genetic improvement programmes including conventional as well as marker assisted breeding towards development of new and desirable turmeric genotypes.     

Difference in microchip electrophoretic mobility between partially and fully PEGylated poly(amidoamine) dendrimers

The objective of this study was to investigate the difference in electrophoretic mobility between partially and fully poly(ethylene glycol)-conjugated poly(amidoamine) dendrimers (part-PEG-PAMAM and full-PEG-PAMAM, respectively) using a microchip capillary gel electrophoresis (MCGE). While MCGE allowed size-based separation of PEG-PAMAMs prepared with monomethoxy PEG-nitrophenyl carbonate, full-PEG-PAMAMs migrated slower than part-PEG-PAMAMs that were similar in size or larger. When the measured molecular weights obtained from MCGE analysis and the calculated molecular weights were plotted, each part-PEG-PAMAM and full-PEG-PAMAM showed correlation coefficients greater than 0.98. This study indicates that MCGE would be useful for characterizing PEG-PAMAMs with different PEGylation degrees.     

Synthesis,characterization and DNA binding and cleavage properties of ruthenium(II) complexes with various polypyridyls

Polypyridyl chlororuthenium(II) complexes have been synthesized and characterized. The binding mode of the complexes to DNA has been evaluated from the combined results of electronic absorption spectroscopy and viscosity measurement study. The results suggest that complexes 1, 2 and 3 bind to DNA via classical intercalation, electrostatic interaction and partial intercalation mode, respectively. Complex 2 shows less affinity for DNA. Cleavage of pUC19 DNA by complexes has been checked using gel electrophoresis. The data disclose that complex 1 has the highest cleaving ability.     

Molecular diversity and association mapping of fiber quality traits in exotic G. hirsutum L. germplasm

The narrow genetic base of cultivated cotton germplasm is hindering the cotton productivity worldwide. Although potential genetic diversity exists in Gossypium genus, it is largely ‘underutilized’ due to photoperiodism and the lack of innovative tools to overcome such challenges. The application of linkage disequilibrium (LD)-based association mapping is an alternative powerful molecular tool to dissect and exploit the natural genetic diversity conserved within cotton germplasm collections, greatly accelerating still ‘lagging’ cotton marker-assisted selection (MAS) programs. However, the extent of genome-wide linkage disequilibrium (LD) has not been determined in cotton. We report the extent of genome-wide LD and association mapping of fiber quality traits by using a 95 core set of microsatellite markers in a total of 285 exotic Gossypium hirsutum accessions, comprising of 208 landrace stocks and 77 photoperiodic variety accessions. We demonstrated the existence of useful genetic diversity within exotic cotton germplasm. In this germplasm set, 11–12% of SSR loci pairs revealed a significant LD. At the significance threshold (r² ≥ 0.1), a genome-wide average of LD declines within the genetic distance at < 10 cM in the landrace stocks germplasm and > 30 cM in variety germplasm. Genome wide LD at r² ≥ 0.2 was reduced on average to  1–2 cM in the landrace stock germplasm and 6–8 cM in variety germplasm, providing evidence of the potential for association mapping of agronomically important traits in cotton. We observed significant population structure and relatedness in assayed germplasm. Consequently, the application of the mixed liner model (MLM), considering both kinship (K) and population structure (Q) detected between 6% and 13% of SSR markers associated with the main fiber quality traits in cotton. Our results highlight for the first time the feasibility and potential of association mapping, with consideration of the population structure and stratification existing in cotton germplasm resources. The number of SSR markers associated with fiber quality traits in diverse cotton germplasm, which broadly covered many historical meiotic events, should be useful to effectively exploit potentially new genetic variation by using MAS programs.     

濒危植物尖叶拟船叶藓的过氧化物同工酶分析

采用聚丙烯酰胺凝胶电泳技术分析了濒危植物尖叶拟船叶藓7个自然居群的过氧化物同工酶．结果表明：尖叶拟船叶藓在13个位点表现酶带．其中 Pod-4、Pod-6、Pod-7为7个居群共有,是尖叶拟船叶藓的特征带;1号居群酶带最多,为12条,除与其他居群共有的3条主带外,还出现了其特有的3务酶带;尖叶拟船叶藓存在哑等位基因现象,有两个稀有基因 Pod-5和 Pod-11．3号和5号、4号和6号有较强的同源性．据此认为尖叶拟船叶藓具有较丰富的遗传多样性．     

Restriction Fragment Length Polymorphism (RFLP) of Genomic DNA of Moraxella (Branhamella) catarrhalis Isolates in a Hospital

Epidemiological typing, based on restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (PFGE), was attempted for the 38 clinical isolates of Moraxella catarrhalis obtained at Shinshu University Hospital during the years 1987 and 1993. Digestion with SmaI or NotI generated well separable, 12 to 5 genomic DNA fragments ranging from 1,000 kb to 30 kb and the strains could be classified into 14 or 13 types, respectively. The electrophoretic profile differed with the strain in most of them and was hence useful to distinguish the each strain. Investigation for their RFLP have, however, suggested that majority of them, including the type strain ATCC25238, may have derived from a common ancestor.     

Lipid biomarkers, pigments and cyanobacterial diversity of microbial mats across intertidal flats of the arid coast of the Arabian Gulf (Abu Dhabi, UAE)

Variations in morphology, fatty acids, pigments and cyanobacterial community composition were studied in microbial mats across intertidal flats of the arid Arabian Gulf coast. These mats experience combined extreme conditions of salinity, temperature, UV radiation and desiccation depending on their tidal position. Different mat forms were observed depending on the topology of the coast and location. The mats contained 63 fatty acids in different proportions. The increased amounts of unsaturated fatty acids (12–39%) and the trans/cis ratio (0.6–1.6%) of the cyanobacterial fatty acid n- 18:1ω9 in the higher tidal mats suggested an adaptation of the mat microorganisms to environmental stress. Chlorophyll a concentrations suggested lower cyanobacterial abundance in the higher than in the lower intertidal mats. Scytonemin concentrations were dependent on the increase in solar irradiation, salinity and desiccation. The mats showed richness in cyanobacterial species, with Microcoleus chthonoplastes and Lyngbya aestuarii morphotypes as the dominant cyanobacteria. Denaturing gradient gel electrophoresis patterns suggested shifts in the cyanobacterial community dependent on drainage efficiency and salinity from lower to higher tidal zones. We conclude that the topology of the coast and the variable extreme environmental conditions across the tidal flat determine the distribution of microbial mats as well as the presence or absence of different microorganisms.