Detection of Resistance and Cross-resistance to Four ALS-inhibiting Herbicides of Scirpus juncoides Roxb. in Paddy Field in Heilongjiang Province

The resistance and cross-resistance of Scirpus juncoides Roxb.to ALS-inhibiting herbicides were tested to provide theoretical basis for effectively control Scirpus juncoides Roxb.and rational use of herbicides.To identify the resistance and crossresistance of 19 populations from nine areas in Heilongjiang Province to four ALS-inhibiting herbicides by agar method and the whole-plant assay.The results are as the followings,the two bioassay methods had good correlation,the resistance indexes in the same area were different by two means,but resistant level was the same,similarity up to 89.5%.The resistant rates to pyrazosulfuronethyl,bensulfuron-methyl,penoxsulam and pyribenzoxim were 26.3%,36.8%,36.1%and 21.1%,respectively.Shangzhi populations evolved the highest level of resistance to pyrazosulfuron-methyl with a resistance index of 15.56.Shangzhi,Tonghe,Fangzheng and Jixi populations showed cross-resistance to four ALS-inhibiting herbicides,accounting for 26.3%.The resistance of Scirpus juncoides Roxb.to four ALS-inhibiting herbicides in Heilongjiang paddy field was low to moderate,five populations showed cross-resistance to four ALS-inhibiting herbicides.

Capacity of Absorption and Removal of Heavy Metals from Scirpus californicus and Its Potential Use in the Remediation of Polluted Aquatic Environment

The research aimed to evaluate the absorption and removal capacity of Cu, Pb, Fe and Zn from Scirpus californicus for potential use in the remediation of polluted aquatic environments. Initially, Scirpus californicus plants were conditioned in 1.5 liters of 10 ppm Cu solution at a pH of 2.3 as well as Pb, Fe and Zn. Subsequently, the concentration of heavy metals in the root-rhizome, submerged stem and aerial stem was determined;the solution and pH were also analyzed. The greatest capacity of absorption and accumulation occurred in the root-rhizome reaching values for Cu of 491.84, Pb of 739.43, Zn of 830.71 and Fe of 2624.72 mg/kg dry followed by the submerged stem and low values for the aerial stem. The removal efficiency of Cu from the solution was 52.10%, Pb 53.50%, Fe 48.00% and Zn 50.20%. It is concluded that the contact time has a significant effect on the absorption and removal capacity of the metals under study.

Fruits of Scirpus(Cyperaceae) from the early Miocene of Weichang,Hebei Province,North China and their palaeoecological and palaeobiogeographical implications

This paper describes the fossil fruits of Scirpus weichangensis X.Q.Liang,sp.nov.from the early Miocene of Guangyongfa Village,Weichang County,Hebei Province,North China.The fossil fruits are obovate in shape and their lateral sections are plumply trigonous.The cell walls of the surface are straight.The persistent stout bristles have downward-directed barbellae in distal 1/2.The occurrence of the fossil Scirpus indicates that Guangfayong was a wetland in the early Miocene.Based on the fossil data,the genus likely originated in Western Siberia in the Oligocene,spread during the Miocene,and was finally distributed worldwide in the Holocene.

Changes in wintering Hooded Cranes and their habitats at Chongming Dongtan over the past 20 years

The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in the past two decades,but there is limited knowledge about the population and habitat changes of the Hooded Cranes.This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021.We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation.The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush(Scirpus mariquter),the main food on tideland for the Hooded Cranes.From 2000 to 2021,the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100.In 2000,the area of Scirpus spp.and Common Reed(Phragmites australis)accounted for approximately half of the total saltmarsh area at Chongming Dongtan,respectively.The invasive Smooth Cordgrass(Spartina alterniflora)rapidly expanded on tideland in the 2000s while the Scirpus spp.was competed out and thus significantly reduced in area.After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp.in the 2010s,the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp.increased.The corms of Sea Bulrush decreased on the southeastern tideland during the study period,which might be the cause of the northward movement of the foraging Hooded Cranes on tideland.We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter,causing human-bird conflicts in the recent decade.Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes.Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland.We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.

云南高原湿地植物水葱的ITS序列分析

提取分布于云南高原湿地的水葱(Scirpus validus Vahl.)样品的DNA,采用ITS序列扩增通用引物,对其进行PCR扩增,并对PCR产物进行测序。从GenBank搜索并下载水葱属其他种类的ITS序列,并通过BioEdit、ClustalX 2.02和MEGA 4x1软件分析和构建系统发育树。分析结果揭示了水葱属14个种之间的亲缘关系,并确定了样品在种间的位置以及和其他种的亲缘关系。

松辽生态区扁秆藨草种群动态变化的研究

本文通过大量的田间调查,摸清了松辽生态区稻田恶性杂草—扁秆蔗草(Scir-pus Planiculmis Schmidt)种群动态变化规律,提出了灭草关健期,为制定科学的灭草方案,有效地控制草害,保证水稻的优质高产,提供了必要的理论根据。

Spatial dynamic patterns of saltmarsh vegetation in southern Hangzhou Bay:Exotic and native species

A saltmarsh has developed rapidly on the mudflat of Andong Shoal,in southern Hangzhou Bay,over the last decade since embankment.The saltmarsh vegetation changes are driven by both sediment dynamic conditions and the competition between the exotic species Spartina alterniflora(S.alterniflora) and the native species Scirpus mariqueter(S.mariqueter).This study attempted to investigate large-scale spatial variations in the exotic and native species,by analyzing and interpreting a time series(2016-2018) of high-resolution(less than 1 m) remote sensing images.The total area of the saltmarsh increased at a rate of 1.07 km^2/year,due to the accretion of the whole tidal flat.The spatial patterns revealed a new bimodal pattern for S.alterniflora invasion.S.alterniflora expanded over the upper to middle saltmarsh at a rate of1.68 km2/year.However,the S.alterniflora patches at the seaward edge expanded at a negative rate of-0.005 km^2/year,indicating a different pattern in competition:S.alterniflora had more advantages in the upper saltmarsh,while S.mariqueter had more advantages in the pioneer zone with low elevation.Consequently,S.alterniflora mainly established new habitats by invading S.mariqueter in the middle saltmarsh,but S.mariqueter occupied the bare mudflat for tradeoff.Our results aindicated that the interspecific competition result between S.alterniflora and S.mariqueter depended on elevation,and low elevation might create a favorable environment for S.mariqueter to win the competition with exotic species.This finding could be applied to future invasive species control and saltmarsh management.

稻田杂草萤蔺的生物学特性及其防除

萤蔺(Scirpus juncoides Roxb.)属莎草科多年生湿生杂草,近年来在我市部分常年施用除草醚的低丘红壤稻区已上升为稻田主要害草之一。据调查,其出现频率早稻田为27.1～76.0％,晚稻田为11.1～80.5％。其中中等以上危害程度的面积早稻田占4.8～25.1％,晚稻田占4.3～30.2％。作者自1986年以来对萤蔺的生物学特性及防除技术进行了观察研究,现将结果报告如下:

Partial function prediction of sulfate-reducing bacterial community from the rhizospheres of two typical coastal wetland plants in China

Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.

藨草的生物学特性及其防除技术研究初报

藨草(Scirpus triqueter),俗称蓑衣草、光棍草等,属莎草科藨草属,是稻田难以防除的多年生恶性杂草之一。长期以来影响了稻谷产量,危害极大。为此,我们对其主要应用生物学特性、分布、危害以及化学防除技术开展了研究,提出了有效的防除方法应用于生产,效果显著。现初报如下。一、藨草的形态特征藨草茎为三棱形,株高一般20～100厘米,由种子发出的实生苗每株有叶片3～4片,再生苗茎基部有4～6厘米的叶鞘包被,着生2张叶片。藨草具有有性繁殖兼行营养繁殖习性,花为长侧枝聚伞花序。

荆三棱在多等级基质异质性与水淹处理下的克隆表现

环境异质性可以影响克隆水生植物的表现。鲜有研究者关注两个层次的环境异质性并将其融入对克隆植物生态学的研究中。本研究的目的是:(1)检验不同基质异质性与水淹处理是否对植物表现产生相似效应,(2)探索克隆植物的觅食行为。本研究将荆三棱(Scirpus yagara)置于不同基质异质性与水淹处理之中。基质处理包括1个均质性基质处理(湖泥与沙等体积混合)与3个异质性基质处理(湖泥斑块与沙斑块交错构建的两斑块、四斑块与八斑块基质)。水淹处理包括:0、10和30 cm。本实验测量了克隆分株数、克隆代数、叶数、球茎数、克隆分株高度、茎长、根状茎长、克隆半径、间隔子长、间隔子厚度、总生物量、球茎生物量与单个球茎生物量等性状数据。研究结果表明,水位上升导致克隆分株数、克隆代数、叶数和球茎数显著减少,同时基质异质性造成间隔子长度与间隔子厚度的显著变化。水位与基质异质性两因子对克隆分株数、叶数和间隔子长度产生了显著的交互效应。在两斑块基质与四斑块基质中,荆三棱对湖泥斑块表现出显著的觅食行为,更多的构件被放置于湖泥斑块中。尤其在两斑块基质中,所有的构件被放置于湖泥斑块中。在八斑块基质中,荆三棱表现出双向觅食,这导致构件在不同斑块中的均匀放置。研究结果表明,荆三棱的觅食行为与斑块大小具有相关性。