12 research outputs found
Teaching geoinformatics in Estonian general education schools
Bakalaureusetöö
Keskkonnakaitse õppekavalGeoinfosüsteemid on olulised erinevate spetsialistide igapäevatöös ning selle õpetamine
põhikoolis või gümnaasiumis arendab õpilastel ruumilist mõtlemist ning aitab õpilastel luua
erinevate eluvaldkondade vahel paremini seoseid. Maa-ameti geoportaali, Google Earth ja
teised rakendused, aitavad kaasa GISi õpetamisele ja GISiga õpetamisele. GISi õpetamisel
oleks kasulik õpetada tundma ka GIS programme (ArcGIS, QGIS või MapInfo) või
veebipõhiseid GIS vahendeid (ArcGIS Online). Geoinformaatika õpetamist Eesti
üldhariduskoolides (põhikoolis ja gümnaasiumis) varem uuritud ei ole. Tartu Ülikoolis on
tehtud kaks magistritööd, mis keskenduvad õpilaste toimetulekule geoinfosüsteemide
kasutamisel. Käesoleva töö eesmärgiks on anda ülevaade geoinformaatikaga seotud teemade
õpetamisest Eesti üldhariduskoolides. Antud töö jaoks analüüsiti põhikooli ja
gümnaasiumiastme geograafia õppematerjale ning valikkursuse Geoinformaatika materjale.
Õppematerjalide analüüsi põhjal koostati õpetajatele mõeldud küsitlus, millest uuriti
geoinformaatikaga seotud teemade õpetamise kohta Eesti üldhariduskoolides. Küsitlusest
selgus, et peamiselt käsitletakse geoinformaatikaga seotud teemasid geograafia tunnis, kuna
enamik vastanuid ei õpeta eraldi ainena geoinformaatikat. Geoinformaatikaga seotud teemade
õpetamisel kasutatakse geograafia õpikut ja internetist leitud materjale. Mõned gümnaasiumid
õpetavad ka eraldi valikkursust Geoinformaatika. Valikkursus Geoinformaatika on mõnes
koolis kohustuslik (peamiselt loodus- ja reaalteaduste suundadele) ja mõnes koolis vabalt
valitav. Tulemustes selgus, et geoinformaatikat on võimalik õpetada ka iseseisva ainena
põhikoolis ning on olemas ka positiivne näide õpetajast, kes õpetab edukalt omaalgatuslikult
põhikoolis eraldi ainena geoinformaatikat.Geographic Information System (GIS) is a important tool for various specialists. Teaching
GIS should start in middle school or high school, because it helps students to develop spatial
thinking and helps them to create better links between different spheres of life. Estonian Land
Board Geoportal, Google Earth and other applications are helpful whether teaching GIS or
teaching with GIS. Teaching GIS it is necessary to teach programs like ArcGIS, QGIS or
MapInfo or a web based ArcGIS Online. Geoinformatics in general education, with similar
objectives, have not been studied previously. Two Master's Thesis from University of Tartu
focuse on the ability of students to use geographic information systems. The aim of this study
was to provide an overview of geoinformatics topics that are taught in general education
schools in Estonia. In this work the author analyzed primary and secondary school geography
teaching materials and a selection course Geoinformatics materials to create a survey. The
survey showed that the teachers are teaching geoinformatic related topics in geography
lessons because most teacher do not teach individually geoinformatics. For teaching
geoinformatics teachers mainly used geography textbooks and materials found on the Internet.
In secondary schools they also teach a specific elective course called Geoinformatics. The
choice of course can be mandatory (mainly the natural and physical sciences students), or
optional. The results showed that geoinformatics can also be taught in primary school, and
there is also a positive example of teachers who have done it successfully
First evidence of bud feeding-induced RNAi in a crop pest via exogenous application of dsRNA
An ecologically sustainable strategy for managing the pollen beetle Brassicogethes aeneus, a key pest of oilseed rape (Brassica napus) in Europe, is greatly needed. Gene silencing via RNA interference, through sprayed applications of target-specific double-stranded RNA, represents a potential alternative to conventional insecticides. We used dsRNA designed to target a vital gene in this pollen beetle species and allowed the beetles to feed on dsRNA-coated oilseed rape buds. We observed a significant silencing of the target gene; and this was followed by a significant, albeit delayed, reduction in pollen beetle survival rate. Further experiments are necessary in order to better understand the potential for developing a dsRNA-spray approach to pollen beetle management.
Spray-induced gene silencing (SIGS) is a potential strategy for agricultural pest management, whereby nucleotide sequence-specific double-stranded RNA (dsRNA) can be sprayed onto a crop; the desired effect being a consumption of dsRNA by the target pest, and subsequent gene silencing-induced mortality. Nucleotide sequence-specificity is the basis for dsRNA's perceived biosafety. A biosafe approach to pollen beetle (Brassicogethes aeneus) management in oilseed rape (Brassica napus) agroecosystems is needed. We examined the potential for SIGS in B. aeneus, via bud feeding, a field-relevant dsRNA exposure route. Oilseed rape buds were uniformly treated with dsRNA designed to target alpha COP in B. aeneus. Our model control dsRNA (dsGFP) remained detectable on buds throughout the entire 3 d exposure period. When applied at 5 mu g/mu L, ds alpha COP induced significant alpha COP silencing 3 d after dietary exposure to buds treated with this ds alpha COP concentration. We also observed a trend of increased alpha COP silencing with increasing concentrations of ds alpha COP at both 3 and 6 d. Furthermore, we observed a marginally significant and significant reduction in B. aeneus survival at 10 and 15 d, respectively. Our results suggest potential for developing a SIGS approach to B. aeneus management-though further experiments are needed to more fully understand this potential
RNAi targets in Agricultural Pest Insects: Advancements, knowledge gaps, and IPM
The unprecedented target-specificity of double-stranded RNA (dsRNA), due to its sequence-specific mode of action, puts dsRNA at the forefront of biosafe insecticide technology. Since 2007, sensitive target genes have been identified in numerous crop pest insects, with an end goal of applying RNA interference (RNAi) in pest management. Key RNAi targets identified include genes involved in (1) feeding and digestion, (2) production of dsRNases, (3) resistance to insecticides and plant allelochemicals, (4) reproductive fitness, and (5) transmission of plant viruses. Despite the advances, there remain critical knowledge gaps in each of these areas. Particular emphasis must be
placed on ensuring RNAi’s compatibility with integrated pest management (IPM), via further identification of molecular targets that reduce crop damage while sustaining pest
(host) populations for highly specialized biocontrol agents, the latter representing a core
pillar of IPM
Targeting a coatomer protein complex-I gene via RNA interference results in effective lethality in the pollen beetle Brassicogethes aeneus
he pollen beetle Brassicogethes aeneus is a serious pest of oilseed rape (Brassica napus) in Europe. Management of this pest has grown difficult due to B. aeneus's development of resistance to pyrethroid insecticides, as well as the pressure to establish control strategies that minimise the impact on nontarget organisms. RNA interference represents a nucleotide sequence-based, and thus potentially species-specific, approach to agricultural pest control. The present study examined the efficacy of targeting the coatomer gene coatomer subunit alpha (alpha COP), via both microinjection and dietary exposure to exogenous complementary dsRNA, on alpha COP-silencing and subsequent mortality in B. aeneus. Beetles injected with dsRNA targeting alpha COP (at 0.14 mu g/mg) showed 88% and 100% mortality at 6 and 10 days post-injection, respectively; where by the same time after dietary exposure, 43%-89% mortality was observed in the 3 mu g dsRNA/mu L treatment, though the effect was concentration-dependent. Thus, the effect was significant for both delivery routes. In working towards RNA-based management of B. aeneus, future studies should include alpha COP as a target of interest
Damage and parasitism rate of seed and stem weevils in winter oilseed rape
Magistritöö
Maastikukaitse ja -hoolduse õppekavalRaps (Brassica napus L.) ehk õlikaalikas on tänapäeval maailmas üks tähtsamaid
õlikultuure (Hatzig et al., 2018). Rapsi kasvupindala laienemine on suurendanud ka
ristõielistele taimedele spetsialiseerunud putukate arvukust ja levikut. Käesolevas töös
käsitletakse rapsi kahjuritest kõdra-peitkärsakat (Ceutorhynchus obstrictus (Marsham)
syn. C. assimilis (Paykull)) ja varre-peitkärsakat (Ceutorhynchus pallidactylus
(Marsham)), kes Eestis kahjustavad peamiselt talirapsi. Rapsil kontrollitakse kahjurite
arvukust peamiselt sünteetiliste putukamürkidega (Heimbach, Müller, 2013; Zimmer et
al., 2014), mis aga hävitavad lisaks kahjuritele ka teised lülijalgsed, sh kahjurite
looduslikud vaenlased (Jonsson et al., 2008; Kovács, 2018). Kiletiivalised (Hymenoptera)
parasitoidid on peitkärsakate ühed kõige olulisemad looduslikud vaenlased. Kõdrapeitkärsaka kolm peamist parasitoidi on: Trichomalus perfectus (Walker), Stenomalina
gracilis (Walker) ja Mesopolobus morys (Walker) (Haye et al., 2015; Ulber et al., 2010).
Antud töö eesmärgiks oli välja selgitada kõdra- ja varre-peitkärsaka kahjustuse suurus
talirapsi põldudel ja kas seda mõjutas kaugus eelmise aasta talirapsi põllust. Selgitati kui
suur oli kõdra-peitkärsaka parasiteerituse tase ja kas seda mõjutas kaugus eelmise aasta
rapsipõllust. Lisaks selgitada, milline oli kõdra-peitkärsaka parasitoidide liigiline koosseis
ja kas eelmise aasta rapsipõllu kaugus mõjutas nende arvukust ja koosseisu. Lähtuvalt töö
eesmärkidest püstitati hüpoteesid: (i) kõdra- ja varre-peitkärsaka kahjustuse taset ei
mõjuta kaugus eelmise aasta rapsipõllust; (ii) kõdra-peitkärsaka parasiteerituse tase on
suurem nendel talirapsi põldudel, mis asuvad lähemal kui 500 meetrit eelmise aasta
talirapsi põllust; (iii) kaugus eelmise aasta talirapsipõllust mõjutab kõdra-peitkärsaka
parasitoidide liigilist koosseisu. Kokku oli 12 katsepõldu, millest kuus asusid lähemal ja
kuus kaugemal kui 500 meetrit eelmise aasta talirapsi tootmispõllust. Leiti, et kõdrapeitkärsaka kahjustuse taset mõjutas kaugus eelmise aasta talirapsi põllust, kuid
parasiteerituse taset ei mõjutanud. Domineerivaks kõdra-peitkärsaka parasitoidiks oli T.
perfectus, kuid leiti ka S. gracilis’e ning M. morys’e isendeid. Varre-peitkärsaka
kahjustuse suurust mõjutas oluliselt kaugus eelmise aasta talirapsipõllust. Põldudel, mis
asusid lähemal kui 500 meetrit eelmise aasta talirapsi põllust oli kahjustuse tase oluliselt
kõrgem kui põldudel, mis asusid kaugemal kui 500 meetrit eelmise aasta talirapsi põllust.
Insektitsiidide kasutamine põldudel mõjutas oluliselt positiivselt kõdra- ja varrepeitkärsakate kahjustuse taset ning oluliselt negatiivselt kõdra-peitkärsaka parasiteerituse
taset.Oilseed rape (Brassica napus L.) is one of the most important oil crops in the world
(Hatzig et al., 2018). The increase in the cultivation area has also increased the abundance
and distribution of oilseed rape pests. Cabbage seed weevil (Ceutorhynchus obstrictus
(Marsham) syn. C. assimilis (Paykull)) and cabbage stem weevil (Ceutorhynchus
pallidactylus (Marsham)), are two abundant and important oilseed rape pests and mainly
harm winter rape oilseed rape in Estonia. Pest management in oilseed rape is mainly based
on the use of synthetic insecticides (Heimbach, Müller, 2013; Zimmer et al., 2014), which
in addition to pests, also kills the natural enemies of pests (Jonsson et al., 2008; Kovács,
2018). Hymenopteran parasitoids are one of the most important group of pest’s natural
enemies. There are three main parasitoid species of cabbage seed weevil: Trichomalus
perfectus (Walker), Stenomalina gracilis (Walker) and Mesopolobus morys (Walker)
(Haye et al., 2015; Ulber et al., 2010). The aim of this work was to find out the extent of
damage done by the cabbage seed weevil and cabbage stem weevil on the winter rape and
whether it was affected by the distance from the previous year's winter oilseed rape fields.
In addition, to find out the parasitism rate of the cabbage seed weevil and whether the
distance of the last years fields affected it. In addition, whether the species composition of
parasitoids was affected on the distance from the previous year's winter oilseed rape fields.
Based on the aims there were three hypotheses: (i) the damage rate of the cabbage seed
weevil and cabbage stem weevil is not affected by the distance of the previous year oilseed
rape fields; (ii) the parasitism rate of cabbage seed weevil is greater in those winter oilseed
rape fields that are located closer than 500 m from the previous year's winter oilseed rape
field; (iii) the distance from the previous year's oilseed rape fields affects the species
composition of parasitoids. In total, there were 12 experimental fields, 6 of which were
located closer than 500 meters from the previous year's winter oilseed rape fields and 6
were further than 500 meters from the previous year's winter oilseed rape fields. We found
that the cabbage seed weevil damage rate was affected by the distance from last year's
winter rape field, but the level of parasitism was not affected by the distance of last year's
winter oilseed rape fields. Trichomalus perfectus was the predominant parasitoid but also
S. gracilis and M. morys were found. The damage rate of the cabbage stem weevil was
significantly influenced by the distance from the previous year’s winter oilseed rape fields.
The damage rate was significantly greater in fields that were closer than 500 meters from
previous years winter oilseed rape fields compared to the fields that were more than 500
meters away from previous years winter oilseed rape fields. The use of insecticides in the
fields significantly reduced the damage rate of the cabbage seed weevil and cabbage stem
weevil and significantly negatively affected the parasitism rate of cabbage seed weevil
Blue stem weevil (Ceutorhynchus sulcicollis) – a potential threat to oilseed rape production
Oilseed rape (Brassica napus) has numerous insect pests, some of which are stem-miners. Currently, blue stem weevil (Ceutorhynchus sulcicollis) is not considered a pest of oilseed rape. In the present study, a total of 60 (30 untreated, 30 insecticide-treated) oilseed rape plants were dissected; and stem-mining larvae were collected, and subsequently allowed to pupate in soil. After pupation, all emerged adult weevils were identified as either blue stem weevil (C. sulcicollis) or cabbage stem weevil (Ceutorhynchus pallidactylus). We report that under favourable conditions C. sulcicollis was capable of reaching pest status, and was significantly more abundant than C. pallidactylus, indicating a critical need for future studies regarding C. sulcicollis
Evaluating the effect of seven plant essential oils on pollen beetle (Brassicogethes aeneus) survival and mobility
Plant essential oils (EOs) represent an area of interest for managing agricultural pests. We examined the insecticidal efficacy of seven plant EOs on the survival and mobility of the pollen beetle Brassicogethes aeneus, a primary pest of oilseed rape (Brassica napus) in Europe. Topical dosing tests showed the EO of the inner bark of Cinnamomum verum (cinnamon) to be the most effective EO examined in our study. Subsequent bioassays, exposing B. aeneus to oilseed rape plant surfaces sprayed with various concentrations of C. verum EO, additionally suggested a concentration threshold at which this EO may significantly control B. aeneus populations. We suggest that further studies on B. aeneus examine the effect of certain pure compounds associated with the most promising EOs (individually as well as in binary combinations) in order to reveal optimal chemical composition and ratios to exploit within a B. aeneus management framework
Examining spray-induced gene silencing for pollen beetle control
Pollen beetles are a transcontinental threat to oilseed rape cultivation. Conventional insecticide use has resulted in resistance development, and can furthermore lead to losses of non-target organisms, including those that contribute to natural biological control of pollen beetle populations. Biosafe alternatives to synthetic pesticides must be explored. Double-stranded RNA (dsRNA) targeting pollen beetle, by the RNA interference (RNAi) mode of action, has been previously demonstrated under laboratory conditions. The present study examined, under a whole plant context, the potential for spray-induced gene silencing (SIGS) in pollen beetle. We confirmed translocation of sprayed dsRNA to later-emerging, non-sprayed dietary tissues of oilseed rape, as well as infiltration of sprayed dsRNA to the inner tissues of reproductive buds (pollen beetle's food source). No effect on survival was observed. The inefficacy of SIGS observed here highlights the requirement for more effective SIGS approaches to pollen beetle management. The translocation of sprayed dsRNA within oilseed rape plants, and the non-significant yet detectable effect on target mRNA downregulation, together suggest potential for future optimization of a SIGS approach against pollen beetle
Anther-Feeding-Induced RNAi in Brassicogethes aeneus Larvae
The biosafety aspect of applying double-stranded RNA (dsRNA) in crop pest management is rooted in dsRNA's mode of action, which displays nucleotide sequence-specificity to a particular region of a messenger RNA (mRNA), against which the insecticidal dsRNA is designed. This prominent and promising class of insecticides therefore has the potential to target a single pest species while conferring negligible effect on non-target organisms. Recent studies examining the effect of target-specific dsRNA in adults of the pollen beetle Brassicogethes aeneus, a major pest of oilseed rape (Brassica napus) crops in Europe, suggest the potential for developing a gene-silencing approach within integrated B. aeneus management. The present study examines the efficacy of target-specific dsRNA on target-mRNA silencing, and subsequent gene-silencing-induced mortality, in B. aeneus larvae, as this life stage represents a critical target for achieving optimal integrated B. aeneus control. Treatment applications occurred via feeding on dsRNA-treated anthers for 3 d. We observed variable gene-silencing efficacy, all target treatments having a significant or marginally significant effect after 3 d of dsRNA feeding, with greater variability at 6 d. These results further validated significant gene-silencing-induced mortality observed for one of the target treatments. Moreover, gene-silencing-induced mortality occurred at a quicker rate in B. aeneus larvae compared to what has been previously observed in B. aeneus adults. Finally, we consider refinements that must be made to B. aeneus larval bioassay setups to promote and strengthen future larval studies regarding this important crop pest species