酸雨胁迫下稀土元素对小麦的生物学效应

酸雨胁迫下稀土元素对小麦的生物学效应＊严重玲１洪业汤１杨先科２付舜珍２吴善绮２（１中国科学院环境地球化学国家重点实验室,贵阳５５０００２;２贵州省环境保护科学研究所ＴｈｅＥｆｅｃｔｏｆＲａｒｅＥａｒｔｈＥｌｅｍｅｎｔｓｏｎＷｈｅａｔＵｎｄｅｒＡｃｉｄ...     

3种荒漠珍稀植物根际促生菌的筛选、鉴定及对高粱幼苗生长的影响

为获得优良植物根际促生菌,本研究从荒漠珍稀植物根际土中分离筛选促生菌,结合16S rDNA基因序列、生理生化特征对其进行鉴定,并通过发芽和盆栽试验分析其促生效果。结果显示：土壤全氮、有效钾、有机质含量较少,呈弱碱性;分离得到5株可固氮、溶磷、产蛋白酶的菌株BN5,HN7,BP4,HD3及SD5,其分别隶属于鞘氨醇单胞菌属（Sphingomonas sp.）、根癌农杆菌属（Agrobacterium tumefaciens）、节杆菌属（Arthrobacter sp.）、磷酸镰孢菌属（Fictibacillus phosphorivorans）及单纯芽孢杆菌属（Bacillus simplex）;5株菌对高粱（Sorghum bicolor）幼苗均表现出促生作用,效果最明显的为菌株BP4,其处理的高粱幼苗发芽势、发芽率、芽长、根长、株高及鲜重较对照组分别增加了55.30%,23.16%,54.52%,40.24%,22.59%,26.67%。本研究结果可为今后荒漠优良菌种资源库的建设提供理论依据。     

稀土对尾叶桉幼林生长及土壤化学性质的影响

通过对稀土不同施用方式(稀土加入基肥、稀土溶液浸根和稀土溶液叶面喷施)对尾叶桉幼林的影响研究,结果表明:3种使用方法都对2.5 a生尾叶按幼林的生长起促进作用,在稀土加入基肥中,使用7.5 g/株效果最好;在稀土溶液浸根中,使用500 mg/kg效果最好;在稀土溶液叶面喷施中,使用200 mg/kg效果最好.从1.5 a生桉树幼林的单株生物量看,稀土加入基肥、稀土溶液浸根和稀土溶液叶面喷施3种施用稀土方式均使桉树幼林生物量得到不同程度的提高.稀土的3种施用方式均能使桉树幼林林地土壤养分含量得到不同程度的提高.影响程度的大小顺序为稀土加入基肥>稀土溶液浸根>稀土溶液叶面喷施.     

Gene flow pattern and mating system in a small population of Quercus semiserrata Roxb. (Fagaceae)

Pollen flow from external sources is important for the conservation of tree species in fragmented forests or small populations, because it can be sufficient to prevent differentiation among them, and appears to be able to prevent the loss of their genetic diversity through genetic drift. In this study, we examined the genetic heterogeneity of pollen pools accepted by each Quercus semiserrata seed parent at the Khun Wang Royal Agriculture Research Center, Thailand, both within and among two mast fruiting years (2005 and 2007), using paternity analysis and analysis of molecular variance (AMOVA). The mating systems of the trees were also examined using the multilocus mating system model (MLTR), after determining the genotypes at eight microsatellite loci of 26 seed-trees and 435 seeds from 8 seed-trees in the 2 mast fruiting years. The average distance of effective pollen flow within the plot was estimated to be 52.4 m, and 95% of effective pollen was dispersed within 200 m, indicating that effective pollen flow is highly localized and that most effective pollen is contributed by near-neighbor trees. The proportion of effective pollen that immigrated from external sources was estimated to be 26.2%. The AMOVA analysis based on the pollen haplotypes showed that the pollen pools, both total and for each reproductive year, significantly genetically differed among the seed parents. Using a mixed mating model, the estimate of biparental inbreeding for the total population (t_m − t_s) was 0.013, indicating that a low proportion of mating occurred among close relatives. The effective number of pollen donors (N_ep) was estimated to be 9.987 using the TwoGener model, or 10.989 using the mixed mating model. The effective number of pollen donors of seeds was higher in the mast fruiting year 2005 than in the other examined year, 2007. Consequently the allelic richness and genetic diversity of seeds produced in 2005 were higher than those produced in 2007. Overall, the results show that high outcrossing rates, high levels of gene flow from other populations and heterogeneity in the pollen received by an individual may enhance the ability of populations to maintain effective population sizes. Therefore, these processes may be sufficient to prevent loss of genetic diversity through genetic drift of Q. semiserrata at this study site.     

九龙县珍稀濒危植物多样性快速评估

采用快速评估技术,利用野外样线和样方调查资料,分析了九龙县主要珍稀濒危植物的种类与分布,探讨了威胁珍稀濒危植物生存的主要影响因子,并提出该县珍稀濒危植物多样性保护的若干建议。     

河南省珍稀保护常绿乔木资源及园林应用研究

于2004～2007年对河南的珍稀保护常绿植物资源进行了调查,结果表明,河南分布有14种国家级重点保护常绿乔木和23种省级童点保护常绿乔木植物;并对它们的观赏特性及其园林利用价值进行了较为详细的分析评价,最后,对其保护及开发利用提出了建议。     

贵州省珍稀濒危植物优先保护等级的定量研究

参考湖南省珍稀濒危植物优先保护分级指标方法,结合贵州省实际,对贵州省69种珍稀濒危植物及特有种进行了优先保护等级的定量研究,划分贵州省珍稀濒危植物优先保护等级,提出了贵州省珍稀濒危植物保护措施。     

几种培养基选择性分离稀有放线菌的方法

介绍了几种培养基选择性分离稀有放线菌的有效方法,如采用葡萄糖-天门冬酰胺改良培养基、淀粉-甘油培养基和甘油-酪素培养基从沙漠土样分离稀有放线菌;利用吉兰糖胶选择性分离Sporichthya,Planobispora,Planom-onospora,Actinomadura rugatobispora等。     

稀土元素对冬凌草细胞合成冬凌草甲素的影响

[目的]探讨稀土元素对冬凌草细胞合成冬凌草甲素的影响。[方法]以冬凌草悬浮培养细胞为材料,研究不同浓度的2种稀土离子镧和亚铈对冬凌草细胞分泌和释放冬凌草甲素的影响。[结果]添加不同种类、不同浓度的稀土离子均可促进冬凌草甲素的合成。添加镧离子的细胞合成的冬凌草甲素明显高于添加铈离子的细胞。当细胞处于延滞期时,添加稀土元素并未产生明显的影响;悬浮培养指数期和稳定期加入稀土元素,均可促进冬凌草细胞对冬凌草甲素的合成,且在稳定期添加稀土元素的效果更加显著。在稳定期加入500μl溶液的培养液,获得的冬凌草甲素含量最高,可达28．89mg／g。[结论]该研究为冬凌草细胞的工业化生产奠定了基础。     

珍稀特有植物掌叶木的研究进展

掌叶木为中国特有的珍稀濒危植物。主要对掌叶木的分类学、形态学、生态学、分子系统学和保护生物学等方面的研究进展进行了综述,并且展望今后的研究方向,认为孢粉学、植物化学、种质保存、人工更新是今后的研究任务。