Iron chlorosis and the iron status of soils

Abstract

The iron status of soils and its relation to iron uptake and iron‐chlorosis is discussed. In many soils, the soluble iron level is so low that rather than having to screen against iron uptake, plants are likely limited in their iron uptake by diffusion. The relationship between the plant root‐soil‐iron environment and the plant's ability to alter this environment is related to the development of iron‐chlorosis.     

A preliminary analysis of phylogenetic relationships ofArundinaria and related genera based on nucleotide sequences of nrDNA (ITS region) and cpDNA (trnL-F intergenic spacer)

Phylogenetic relationships ofArundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNAtrnL-F intergenic spacer (IGS). Comparison withtrnL-F IGS sequence, the ITS region provided the higher number of parsimony informative characters, and the interspecific variation of the ITS sequence was higher than that of thetrnL-FIGS sequence. The tree obtained by combining both sets of data showed that the species sampled inArundinaria and the related genera were monophyletic and divided into two clades. The relationships and positioning of all the taxa surveryed (includingA. oleosa, A. hsienchuensis, A. chino, A. amara, A. yixingensis, A. amabilis, A. fortunei, A. pygmaea, A. gramineus, A. fargesii, A. faberi, A. hupehense, Pseudosasa japonica cv. Tsutsumiana, P. japonica andBrachystachyum densiflorum) were also discussed. The results from the sequences were broadly consistent with morphological characters, appearing all these taxa sampled belong to the genus ofArundinaria. The topologies of the trees generated from individual data and the combined data were similar. Foundation item: This study was supported by National Natural Science Foundation of China (No. 30170788) Biography: ZHUGE Qiang (1959-), male, professor in Laboratory of Forest Genetics and Gene Engineering, Nanjing Forestry University, Nanjing 210037, P.R. China. Responsible editor: Song Funan     

Mobilising environmental information about lesser-known plants: the value of two neglected levels of description

Difficulties exist at present in predicting the performance of many lesser-known plants because of the high cost of elucidating their environmental relationships using conventional experimental methods. It is pointed out that prior to the emergence of modern plant science, mankind must have been using coarser methods very similar to those observable in human communities today. Because these instinctive human methods appear to be very effective, a fresh look at them could lead to alternative ways of defining the environmental relationships of lesser-known plants. These methods could be much cheaper and quicker than conventional methods and could make use of a large pool of knowledge about plants which is held in human communities. The most appropriate medium for interaction with the public in this way appears to be shareware software, and a package called PLANTGRO which could aid such developments is foreshadowed.     

基于COI基因探讨雉科6个属的分类地位

试验测定了雉科4属7种的81条COI序列,获得片段长度为690 bp,并从Genbank、BOLD中获取21属46种的相应序列,进行了序列和系统发生分析。通过计算属间遗传距离,并以中华秋沙鸭(Mergus squamatus)、马来闭壳龟(Cuora amboinensis)为外群,用NJ法、ME法和ML法对雉科46种鸟类构建系统发育树,来探讨雉科内存在争议属的分类问题。结果表明:血雉与鹑类关系更近;雪鸡属与石鸡属关系很近;山鹑属始终与鹌鹑属聚在一起;勺鸡属与雉鹑属相邻而自成一个支;原鸡属与竹鸡属和鹧鸪属始终聚在一起;山鹧鸪属最先分化出来,在整个雉科类群的基部。     

大学校园景观的文化表达

摘要：笔者通过对文化表达与景观表现的认识与思考,提出了景观的文化表达的思想：用景观的语言来表达文化,用文化的情感来诠释景观的一个过程。同时,注重对场地的空间分析,赋予场地空间情感,形成多元化的文化空间,并结合湖南第一师范学院东方红校区景观设计的过程分析,对大学校园景观的文化表达经行了详细的解读。     

种植业机械化程度与劳动力需求的关系模型

该文提出并探讨了种植业机械化程度与劳动力需求关系问题。其目的旨在发展完善农业机械化理论,为科学估算种植业劳动力数量和农村剩余劳动力数量提供理论参考。该文首先分析指出了用同型号的机组替代种植业劳动力具有线性替代关系,指出了机械化程度具有可分性,并对其进行了证明。在此基础上,建立了种植业机械化程度与劳动力需求关系模型,利用该模型不仅能够计算某一地区目前种植业劳动力需求数量,而且通过对未来各种作物机械化程度和播种面积的预测,也可计算出未来各时刻的种植业劳动力需求数量。最后进行了示例计算。     

Using habitat models to identify suitable sites for marine protected areas for harbour porpoises (Phocoena phocoena)

The harbour porpoise is a highly mobile species and thus represents a considerable challenge in the context of using marine protected areas (MPAs) for conservation. The shelf waters off the west coast of Scotland have been identified as an area of year-round presence, high density in comparison to surrounding areas, and a high young to adult ratio in summer and are thus a suitable area for exploring the location of possible special areas of conservations (SACs) under the EU Habitats Directive. We carried out dedicated surveys over three summers in the southern Inner Hebrides and used generalised additive models (GAMs) to predict areas of high relative density for harbour porpoises for each year. After compensating for survey effects, static bathymetric and persistent hydrographic variables were used in a step-wise model selection procedure. In all years harbour porpoise distribution was best explained by maximum tidal current, with higher densities predicted in areas of low current, and the same high density areas predicted year-on-year. Perimeter-to-area ratio was used to identify which areas should be considered as a basis for designating SACs for harbour porpoise in this area, to form part of the Natura 2000 network. The method used here combines spatial modelling and perimeter-to-area ratio for selecting protected areas, a methodology which is suitable for the protection of other animal species.     

HPPD抑制剂的研究进展

对新型除草剂对羟苯基丙酮酸双氧化酶 (HPPD)抑制剂的发现过程、作用机制、结构特征、构效关系以及合成方法作了较为详细的综述     

The pyrethrins and related compounds part XL— structure-activity relationships of pyrethroidal esters with acyclic side chains in the alcohol component against resistant strains of housefly (Musca domestica)

Activities of a range of pyrethroidal esters, incorporating structural variations in all regions of the acid and alcohol components, have been measured against two fully characterised and homozygous resistant strains of Musca domestica (kdr and super-kdr). The results, limited in this paper to esters of alcohols with acyclic side chains, show the same level of uniform resistance as the kdr strain observed previously, across a range of acid and alcohol variations. Against the super-kdr strain, in contrast to the cyclic side chain set, resistance factors are barely higher than for the kdr strain. Against super-kdr flies, some dependence of resistance factor on the position of the side chain substituent was detected. Polyfluorobenzyl esters confer particularly low resistance factors.     

Insect pollinators of the invasive plant, Rosa multiflora (Rosaceae), in Iowa, USA

Invasive species often require mutualistic relationships to successfully invade new environments. Insect pollination is an example of a mutualism that is required for seed-set in the invasive species, Rosa multiflora Thunb. (Rosaceae), an obligate outcrosser. To determine the insect pollinators visiting R. multiflora flowers in Iowa, USA, we collected insects on yellow sticky traps placed on plants during the period of blooming and visually observed insects visiting the flowers. The common insect orders that were collected on the sticky traps included Coleoptera, Diptera, Hemiptera, Hymenoptera, Mecoptera, and Thysanoptera. Many of the insects found on the sticky cards were known to feed on pollen. However, we did not collect Apidae (bumble bees and honey bees) on the sticky cards. We observed Bombus spp. and Apis mellifera foraging on the flowers. Syrphid flies were the most commonly observed taxa visiting the flowers. Our results indicate that R. multiflora is utilizing common generalist insect pollinators in Iowa and that pollination is not a limiting factor for this invasive species.