植物冠瘿生长调控及相关基因研究进展

阐述了植物冠瘿产生的影响因素及冠瘿的生长和调控,并对冠瘿发生有关的基因进行了综述。     

鄂尔多斯高原特有种四合木生长和繁殖的种群间变异与濒危机制

四合木为中国特有种,其分布区局限于鄂尔多斯高原的西部。为了认识四合木濒危的机制并为其保护提供理论依据。对四合木生活史的关键阶段－－繁殖进行了野外研究,由于分布区内存在较大的生境异质性,并受到了不同强度的人类干扰,所以不同生境条件下的6个群进行了取样,通过对四合木的营养生长和繁殖的比较分析。得出如下结论：（1）四合木植要朱的基径和冠幅和高度与年龄显著相关,但是与其茎和冠幅相关性更大,冠幅可作为个体大小的测度估计种群的大小结构;（2）冠幅大小呈负偏斜分布,通过不同种群冠幅与年龄的相关分析,得出冠幅的增长速率随种群的衰老耐减缓;（3）四合木的冠幅与其果实量和种子量相关关系显著,随着冠幅的增大,四合木植株的果实产量和种子产量也相应增加,但是这种关系存在种群间差异;（4）四合木的大部分群都处于衰老期,种群内个体的大小变异性很小,对于种群的生存有不利影响;（5）由于空间上四合木的大小结构以及反映四合木繁殖状况的植株果实产量,种子产量等参数在不同种群之间存在显著差异（P＜0．001）,因此应对不同的种群采取相应的管理措施以促进种群的更新和续存。     

西洋参冠瘿组织培养及其人参皂苷Re和人参皂苷Rg1的产生

考察了培养基组成、培养时间、接种量、pH值、肌醇浓度等对冠瘿组织生长及其人参皂苷含量的影响 ;用HPLC检测了冠瘿组织中人参皂苷Re和人参皂苷Rg1 的含量。高压纸层析电泳证实 ,根癌农杆菌Ti质粒上的T DNA片段已整合进入植物细胞核基因组中。在考察的 6种培养基中 ,White培养基最适合人参皂苷Rg1 的累积(0 0 95 % ) ,MS培养基最适合人参皂苷Re的累积 (0 194 % )。以MS为基本培养基培养 36d、32d时人参皂苷Re和人参皂苷Rg1 累积含量最高 (分别为 0 14 7%和 0 0 6 1% ) ;接种量为 4g、2g (FW flask) ,有利于人参皂苷Re和人参皂苷Rg1的累积 ;培养基pH 5 8时人参皂苷Re含量最高 (0 184 % ) ,培养基pH 5 6时人参皂苷Rg1 累积量最高 (0 0 5 4 % ) ;肌醇浓度为 0 0 5g L时 ,能促进人参皂苷Re合成 (0 182 % ) ,浓度为 0 30g L时 ,有利于人参皂苷Rg1 累积 (0 0 5 5 % )。     

Effects of Metalaxyl, Fosetyl-Al, Dimethomorph and Cymoxanil on Phytophthora cactorum of Peach Tree

The activity of metalaxyl, fosetyl-Al, dimethomorph, and cymoxanil against Phytophthora crown rot of peach trees was examined. Application of fosetyl-Al or metalaxyl by painting the trunk (150 g/l) of 3-year-old PR204 trees was inhibitory to growth of the fungus but neither dimethomorph nor cymoxanil were effective. Application of metalaxyl as a soil drench suppressed canker development when the treated trees were subsequently inoculated with Phytophthora cactorum . Fosetyl-Al significantly reduced the growth of fungus compared with cymoxanil, dimethomorph and control but it was not as effective as metalaxyl. Again, dimethomorph and cymoxanil did not influence canker development. Both metalaxyl and fosetyl-Al were active for at least 21 days after applications. Strips of trunk bark were removed from trees, that had been drenched with the tested chemicals 20 days before, and inoculated on the cambium side with P. cactorum . Metalaxyl was the most effective fungicide and fosetyl-Al significantly reduced the development of fungus compared with dimethomorph, cymoxanil and the untreated strips. Colonization of strips treated with dimethomorph was significantly less than untreated strips. In contrast, cymoxanil did not inhibit the growth of fungus. Application of metalaxyl or fosetyl-Al as trunk paint or a soil drench appear to be effective procedures for preventing Phytophthora rot of peach trees.     

Preferential expression of linear enamel hypoplasia on the sectorial premolars of rhesus monkeys (Macaca mulatta)

Three hundred and sixty rhesus macaque specimens at the Caribbean Primate Research Center were examined for evidence of linear enamel hypoplasia (LEH). A previously unreported intertooth pattern in LEH was observed. Defects occur preferentially on the sectorial premolar of both males and females. Relative to other teeth, the sectorial premolar exhibits more prominent defects and is more likely to exhibit multiple defects. This pattern is unlike the human intertooth LEH pattern and unlike patterns previously reported for monkeys and apes. These observations are discussed in the context of factors thought to influence the intertooth distribution of LEH in humans and in nonhuman primates. The authors reject crown height, the timing of crown development, and the duration of crown formation as factors contributing to the observed pattern and favor an explanation involving enamel thickness, perikymata spacing, and/or prism orientation. Am J Phys Anthropol 107:179–186, 1998. © 1998 Wiley-Liss, Inc.     

Dental size and shape in the Roman imperial age: Two examples from the area of Rome

Different socioeconomic strata of Roman imperial age are represented by two large dental samples recovered from archaeological excavations near Rome, Italy. Teeth are investigated for crown dimensions and morphological variants. One sample, comprising 1,465 permanent teeth, represents the rural town of Lucus Feroniae (LFR) and is mainly composed of slaves and war veterans. The other, comprising 734 teeth from the Isola Sacra necropolis at Portus Romae (NIS), represents the “middle class” segment of an urban population. Both series show small dental dimensions and fit at the lower end of the trend toward dental reduction in Europe from the Upper Paleolithic to the historical times. The urban sample is less variable metrically and less sexually dimorphic than the rural one. The analysis of discrete crown traits shows absence of rare phenotypic variants in both series. The urban sample is also less variable in this last respect, suggesting that the gene pool of this particular “stratum” of the NIS population was more homogeneous than that of LFR. The occurrence of enamel hypoplasia indicates that metabolic stress during growth and development was similar in LFR and NIS. The overall set of available data is evaluated in the light of the history of the two Roman sites and the composition of each population. Am J Phys Anthropol 102:469–479, 1997. © 1997 Wiley-Liss, Inc.     

Characteristic high- and low-frequency dental traits in sub-Saharan African populations

In an earlier investigation (Irish [1993] Biological Affinities of Late Pleistocene Through Modern African Aboriginal Populations: The Dental Evidence [Ann Arbor: University Microfilms]), biological affinities of 32 sub-Saharan and North African dental samples were estimated using comparative analyses of 36 dental morphological traits. Marked dental homogeneity was revealed among samples within each of the two geographic regions, but significant interregional differences were noted. Assuming dental phenetic expression approximates or is an estimate of genetic variation, the present study of 976 sub-Saharan-affiliated Africans indicates they are not closely related to other world groups; they are characterized by numerous morphologically complex crown and root traits. Turner ([1984] Acta Anthropogenetica 8:23–78; [1985] in R Kirk and E Szathmary (eds.): Out of Asia: Peopling the Americas and the Pacific [Canberra: The Journal of Pacific History], pp. 31–78; [1990] Am. J. Phys. Anthropol. 82:295–318; [1992] Persp. Hum. Biol. 2/Archaeol. Oceania 27:120–127; [1992] in T Akaszawa, K Aoki, and T Kimura (eds.): The Evolution and Dispersal of Modern Humans in Asia [Tokyo: Hokusen-Sha Publishing Co.], pp. 415–438) reports that Northeast Asian/New World sinodonts also have complex teeth relative to Europeans, Southeast Asian sundadonts, Australian/Tasmanians, and Melanesians. However, sinodonty is characterized by UI1 winging, UI1 shoveling, UI1 double shoveling, one-rooted UP1, UM1 enamel extension, M3 agenesis, and three-rooted LM1. Sub-Saharan peoples exhibit very low frequencies of these features. It is proposed that the collection of dental traits which best differentiate sub-Saharan Africans from other worldwide samples includes high frequencies of the Bushman Canine, two-rooted UP1, UM1 Carabelli's trait, three-rooted UM2, LM2 Y-groove pattern, LM1 cusp 7, LP1 Tome's root, two-rooted LM2, UM3 presence, and very low incidences of UI1 double shoveling and UM1 enamel extension. This suite of diagnostic traits is termed the sub-Saharan African dental complex. Am J Phys Anthropol 102:455–467, 1997. © 1997 Wiley-Liss, Inc.     

Cervical and crown outline analysis of worn Neanderthal and modern human lower second deciduous molars

Despite the general increase in digital techniques for dental morphometric analyses, only a few methods are available to study worn teeth. Moreover, permanent dentitions are studied much more frequently than deciduous teeth. In this study, we address both issues by providing a taxonomic classification of Neanderthal and modern human (MH) lower second deciduous molars (dm₂s) through the analysis of crown and cervical outlines. Crown and cervical outlines were obtained from a three‐dimensional (3D) digital sample of uniformly oriented dm₂s. Both outlines were centered on the centroid of their area and represented by 16 pseudolandmarks obtained by equiangularly spaced radial vectors out of the centroid. We removed size information from the oriented and centered outlines with a uniform scaling of the pseudolandmark configurations to unit Centroid Size. Group shape variation was evaluated separately for the dm₂ crown and cervical outlines through a shape–space principal component (PC) analysis. Finally, quadratic discriminant analysis of a subset of PCs was used to classify the specimens. Our results demonstrate that both outlines successfully separate the two groups. Neanderthals showed a buccodistal expansion and convex lingual outline shape, whilst MHs have buccodistal reduction and straight lingual outline shape. Therefore, we confirmed that the cervical outline represents an effective parameter for distinguishing between the two taxa when dealing with worn or damaged dm₂s. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.     

豌豆茎基腐病病原菌分离鉴定及其对杀菌剂的敏感性测定

豌豆(Pisum sativum)是我国重要的豆类经济作物, 病害对豌豆生产造成重大经济损失。通过形态学观察、分子鉴定以及致病性测定, 最终确定引起豌豆茎基腐病的3种病原菌分别为尖孢镰刀菌(Fusarium oxysporum)、芸苔链格孢菌(Alternaria brassicae)和格氏镰刀菌(F. grosmichelii), 优势菌株为尖孢镰刀菌, 分离率为53.6%。室内毒力测定结果表明, 5种供试杀菌剂对3种病原菌的菌丝生长均有抑制作用, 其中咯菌腈和戊唑醇的抑菌效果最好。研究结果为豌豆茎基腐病的防治提供了科学依据。     

Growth and development of seminal and crown root systems in N-limited barley,and their contributions to nitrate acquisition during vegetative and generative growth

Barley (Hordeum vulgare L., cvs Golf and Laevigatum) was grown under nitrogen limitation, controlled by the relative rate of nitrate-N addition (RA), in solution culture. The seminal and crown root systems were kept apart, but in contact with the same nutrient solution throughout culturing. Growth, nitrate uptake, and in vitro nitrate reductase (NR) activity in the different root parts were studied at plant ages from 40 (late vegetative stage) to 110 (mid grain-filling) days. The RA was during this time interval stepwise decreased from 0.08 day^–1 to 0.005 day^–1. The ratio between seminal root dry weight and total plant dry weight decreased drastically during post-anthesis growth, whereas the contribution by crown roots remained unchanged. Tissue nitrogen concentrations in seminal roots did not change with time, but decreased in crown roots after day 80. The NR activity decreased with age in both seminal and crown roots. The V_max for net nitrate uptake decreased throughout the experiment in the seminal root system, but not in the crown root system. The kinetic properties (V_max and K_M) were used to calculate the nitrate concentration required to maintain a relative rate of nitrate-N uptake that equals the relative addition rate. These concentrations (2 to 5 mmol m^–3) were found to closely match actually measured nitrate concentrations in the nutrient solution (1 to 6 mmol m^–3). From uptake kinetics, it was deduced that the contribution by seminal roots to total nitrate uptake at these concentrations decreased from more than 50% in vegetative plants, to about 20% just after main shoot anthesis, and to less than 5% during grain-filling. ei]Section editor: H Lambers