Cisgenese drukt kosten phytophthorabestrijding
Kessel, G.J.T. - \ 2014
Boerderij 99 (2014)49. - ISSN 0006-5617 - p. 61 - 61.
akkerbouw - aardappelen - gewasbescherming - genetische gewasbescherming - resistentie van variëteiten - phytophthora infestans - plantenveredeling - cisgenese - kosten - opbrengst - veldproeven - arable farming - potatoes - plant protection - genetic control - varietal resistance - phytophthora infestans - plant breeding - cisgenesis - costs - outturn - field tests
Wageningen UR test op aardappelen die via cisgenese zijn voorzien van een of meer genen, die ze beter bestand maken tegen phytophthora. Bij cisgenese worden soorteigen genen uit wilde aardappelplanten gebruikt. (Bij transgenese gaat het om soortvreemde genen.)
Glastuinbouw Waterproof, substraatteelt : WP5, Fase 3: pilotonderzoek membraandestillatie
Appelman, W. ; Creusen, R. ; Jurgens, R. ; Medevoort, J. van; Zijlstra, M. ; Os, E.A. van - \ 2012
Apeldoorn : TNO Earth, Environmental and Life Sciences - 29
glastuinbouw - substraten - teeltsystemen - regelingen - oppervlaktewater - oppervlaktewaterkwaliteit - emissiereductie - npk-meststoffen - genetische gewasbescherming - greenhouse horticulture - substrates - cropping systems - regulations - surface water - surface water quality - emission reduction - npk fertilizers - genetic control
Het doel van het project is de realisatie van de Kaderrichtlijn water doelen voor het oppervlaktewater in glastuinbouwgebieden door het voorkomen van de emissies van nitraat, fosfaat en gewasbeschermingsmiddelen uit substraatteelten in de glastuinbouw.
Fysische inductie van meeldauwresistentie in roos, Thema: Innovaties duurzame gewasbescherming BO-12.03-003.02-002
Stevens, L.H. ; Davelaar, E. ; Hofland-Zijlstra, J.D. ; Snel, J.F.H. ; Driever, S.M. - \ 2011
genetische gewasbescherming - gewasbescherming - duurzaamheid (sustainability) - teeltsystemen - meeldauw - innovaties - geïntegreerde plagenbestrijding - genetic control - plant protection - sustainability - cropping systems - mildews - innovations - integrated pest management
Informatieposter over fysische inductie van meeldauwresistentie in roos (thema: innovaties duurzame gewasbescherming). Bestaande chemische gewasbeschermingsmiddelen tegen echte meeldauw in roos worden verboden of blijken vaak onvoldoende effectief. Er is behoefte aan een nieuwe aanpak die geen registratie vereist en past in een geïntegreerd maatregelenpakket
Behavioural, ecological, and genetic determinants of mating and gene flow in African malaria mosquitoes
Ng'habi, K.R.N. - \ 2010
Wageningen University. Promotor(en): Marcel Dicke, co-promotor(en): B.G.J. Knols. - - 201
anopheles gambiae - anopheles arabiensis - culicidae - paringsgedrag - genenstroom - dierecologie - vectorbestrijding - genetische gewasbescherming - diergenetica - anopheles gambiae - anopheles arabiensis - culicidae - mating behaviour - gene flow - animal ecology - vector control - genetic control - animal genetics
Botrytis in tomaat: wat aanpakken en hoe?
Meijer, Rob - \ 2009
market gardens - vegetable growing - tomatoes - fruit vegetables - botrytis - deuteromycotina - pest control - infections - disease prevention - genetic control - pesticides - greenhouse horticulture
|Knelpunten in de biologische veredeling; een stap verder: resultaten onderzoeksprogramma 2004-2007
Lammerts Van Bueren, E. ; Osman, A.M. ; Tiemens-Hulscher, M. ; Timmermans, B. ; Scholten, O.E. ; Voorrips, R.E. ; Burger, K. ; Steenhuis, M.M. ; Galvan, G. - \ 2008
Ekoland 2008 (2008)1. - ISSN 0926-9142 - p. 26 - 29.
biologische landbouw - gewasbescherming - genetische gewasbescherming - plantenveredeling - koolsoorten - daucus - tarwe - allium cepa - onderzoek - biologische plantenveredeling - organic farming - plant protection - genetic control - plant breeding - cabbages - daucus - wheat - allium cepa - research - organic plant breeding
De biologische landbouw kent voor sommige gewasssen specifieke knelpunten die via de teelt moeilijk aangepakt kunnen worden, maar die via de veredeling wél behandeld kunnen worden. In de afgelopen vier jaar heeft in het kader van Bioconnect een onderzoeksprogramma gelopen om de ontwikkeling van betere rassen te ondersteunen. Het onderzoek heeft zich vooral gericht op de weerbaarheid tegen trips (kool), zwarte vlekken (peen) en fusarium (tarwe) en op het ontwikkelen van nieuwe veredelingsstrategieën (ui)
Reproductive biology and induced sterility as determinants for genetic control of mosquitoes with the Sterile Insect Technique
Helinski, M. - \ 2008
Wageningen University. Promotor(en): Marcel Dicke, co-promotor(en): B.G.J. Knols. - S.l. : S.n. - ISBN 9789085049555 - 203
steriele insecten techniek - genetische gewasbescherming - sterilisatie - ioniserende straling - stabiele isotopen - ziekten overgebracht door muskieten - malaria - anopheles arabiensis - paarconcurrentie - sudan - sterile insect release - genetic control - sterilization - ionizing radiation - stable isotopes - mosquito-borne diseases - malaria - anopheles arabiensis - mating competitiveness - sudan
Malaria remains an important health issue in sub-Saharan Africa, and new methods to reduce the disease are needed. In this thesis, the use of the Sterile Insect Technique (SIT) against the African malaria vector Anopheles arabiensis was explored. The SIT relies on the releases of large numbers of sterilised males. If the sterile males are successful in competing for mates and the females use their sperm for fertilisation, the wild population is reduced. Ultimately, this can lead to a reduction in disease incidence. Sterilisation of the sperm cells occurs by ionising radiation, resulting in the death of the developing embryo after fertilisation. Somatic cells are also damaged, which can lead to a reduced mating competitiveness of the males.
In this thesis I investigated 1) the relationship between dose and induced sterility for pupal or adult stage irradiation, 2) sperm quantity and sperm length polymorphism and the influence of irradiation, 3) the use of stable isotopes to determine mating in mosquitoes, 4) the incidence of multiple mating in relation to irradiation, 5) the fitness of irradiated males in terms of survival and mating competitiveness, and 6) the use of a field cage for mating studies, and the small-scale feasibility of the SIT in Sudan.
Results showed that even though the dose-response curves between dose and induced sterility were largely similar for pupae and adults, irradiation of adults resulted in a better competitiveness compared to pupal irradiation. A negative relationship between dose and competitiveness was observed for pupal stage irradiation. In addition, radiation during the pupal stage affected the number of spermatozoa in the testes and the distribution of sperm lengths, but no impact on the incidence of multiple mating could be observed. Stable isotopes were used successfully to determine paternity in mating. Mating competitiveness of males irradiated as pupae could be improved by a three-fold increase in their number compared to un-irradiated males, but only for the partially-sterilising dose. The small-scale irradiation and transportation of insects in Sudan was feasible, and the preparation of the field cage for experiments successful.
It is concluded that from a biological viewpoint the irradiation of adults would be recommended; however, the feasibility of adult irradiation on a large scale is questionable. The next steps would be to scale up irradiation procedures to accommodate much larger numbers of insects, and to determine male competitiveness in the semi-field system in Sudan. However, many other factors including mass rearing, sexing, and release methodology, are of importance for an SIT programme and only when all components are in place can the true feasibility of the SIT in Sudan be determined.
Het waarom en hoe van DuRPh: duurzame resistentie tegen Phytophthora in aardappel door cisgene merkervrije modificatie
Haverkort, A.J. ; Boonekamp, P.M. ; Jacobsen, E. ; Lotz, L.A.P. ; Visser, R.G.F. - \ 2007
Gewasbescherming 38 (2007)5. - ISSN 0166-6495 - p. 238 - 241.
aardappelen - vermeerderingsmateriaal - rassen (planten) - phytophthora infestans - plantenziekteverwekkende schimmels - pesticiden - genetische modificatie - milieueffect - plaagresistentie - innovaties - duurzaamheid (sustainability) - celkloneren - veredelingsmethoden - genetische transformatie - genetische gewasbescherming - economie - potatoes - propagation materials - varieties - phytophthora infestans - plant pathogenic fungi - pesticides - genetic engineering - environmental impact - pest resistance - innovations - sustainability - cell cloning - breeding methods - genetic transformation - genetic control - economics
Begin 2005 verzocht de interdepartementale Commissie Biotechnologie Wageningen UR een onderzoeksprogramma op te stellen voor een perspectiefvol GMO-project. Dit met het oog op de Nederlandse innovatieagenda en behoud of vergroting van de concurrentiekracht van de Nederlandse economie. Uitgangspunt daarbij was de Integrale Nota Biotechnologie (2000) met als centraal motto het verantwoord en zorgvuldig benutten van kansen ten behoeve van economie en duurzame landbouw. De keuze viel op een 'proof of principle' project van een duurzaam Phytophthoraresistente aardappel vanwege de economische aspecten zoals de kosten van beheersing van de ziekte en het veiligstellen van de winstgevendheid van de pootgoedsector. Milieuaspecten zoals reductie van de emissie van chemicaliën en een verminderd energiegebruik voor de toediening telden eveneens mee alsook het vergroten van de wetenschappelijk innovatiekracht
Proceedings of the joint WHO/TDR, NIAD, IAEA and Frontis workshop on bridging laboratory and field research for genetic control of disease vectors, Nairobi, Kenya 14-16 July 2004
Knols, B.G.J. ; Bossin, H. - \ 2006
Dordrecht : Springer (Wageningen UR Frontis series vol. 11) - ISBN 9781402037993 - 225
vectoren, ziekten - vectorbestrijding - genetische gewasbescherming - laboratoriumproeven - veldproeven - insecten - insects - disease vectors - vector control - genetic control - laboratory tests - field tests
Contemporary research on genetic control of disease-transmitting insects knows two kinds of scientists: those that work in the laboratory and those known as `field people¿. Over the last decade, both groups seem to have developed differing research priorities, address fundamentally different aspects within the overall discipline of infectious-disease control, and worse, have developed a scientific `language¿ that is no longer understood by the `other¿ party. This gap widens every day, between the North and the South, between ecologists and molecular biologists, geneticists and behaviourists, etc. The need to develop a common research agenda that bridges this gap has been identified as a top priority by all parties involved. Only then shall the goal of developing appropriate genetic-control strategies for vectors of disease become reality. This book is the reflection of a workshop, held in Nairobi (Kenya) in July 2004, that addressed the above issues. It brought together a good representation of both the molecular and ecological research disciplines and, for the first time, included a significant number of researchers from disease-endemic countries. The research agenda presented here will serve the research and science-policy communities alike, and guide sponsoring organizations with the selection of priority areas for research funding
Breeding programmes for elimination of alleles in rare breeds: scrapie in the Netherlands
Windig, J.J. ; Lansbergen, L.M.T.E. - \ 2006
dierveredeling - schapen - veredelingsprogramma's - ziektebestrijding - ziekteresistentie - genen - genetische gewasbescherming - genetische stoornissen - inteelt - stamboom - rammen - scrapie - nederland - animal breeding - sheep - breeding programmes - disease control - disease resistance - genes - genetic control - genetic disorders - inbreeding - pedigree - rams - scrapie - netherlands
Small populations often suffer from genetic defects. Single gene defects can be eliminated by selection for specific alleles, but then there is a risk of increased inbreeding with associated loss of genetic variation, inbreeding depression and increased frequency of other genetic defects. Here we investigate special breeding programs for scrapie resistance with inbreeding restriction. A ram circle, where each flock uses rams from another flock, is most suited for situations where pedigrees are unknown and animals are herded in large flocks. Inbreeding minimization with optimal contribution theory is most suited when pedigree records are available and a few breeders provide most rams for the whole population. Both schemes considerably reduced inbreeding rates in the Kempisch Heideschaap and in the Mergellander
Durable resistance against Meloidogyne spp. possible for italian ryegrass?
Kruijssen, L. van; Nes, M. van; Loeffen, E. ; Jager, J. ; Zoon, F.C. ; Poleij, L.M. - \ 2003
lolium - graslandbeheer - gewasbescherming - genetische gewasbescherming - meloidogyne - resistentie van variëteiten - resistentieveredeling - lolium - grassland management - plant protection - genetic control - meloidogyne - varietal resistance - resistance breeding
The variation in resistance to Meloidogyne chitwoodi and M. fallax in italian ryegrass has been studied in order to breed more resistant ryegrass varieties.
Molecular characterisation of QTLs controlling fatness in pigs
Rattink, A.P. - \ 2002
Wageningen University. Promotor(en): J.A.M. van Arendonk; M.A.M. Groenen. - S.l : S.n. - ISBN 9789058086129 - 125
varkens - kruising - loci - kwantitatieve kenmerken - chromosoomkaarten - genkartering - genetische gewasbescherming - genetische merkers - genomic imprinting - lichaamssamenstelling - rugspek - lichaamsvet - chromosomen - genen - moleculaire genetica - pigs - crossbreds - loci - quantitative traits - chromosome maps - gene mapping - genetic control - genetic markers - genomic imprinting - body composition - backfat - body fat - chromosomes - genes - molecular genetics
This thesis deals with the identification of genes controlling intramuscular fat and backfat thickness. Markers linked to quantitative trait loci (QTL) for these traits in the cross between Meishan x Large White breeds will lead to the identification of the underlying genetic causes. A whole-genome scan revealed significant evidence for five QTLs affecting body composition, of which four were imprinted. Additional markers were typed in this cross to further investigate the regions on pig chromosome (SSC) 2, SSC4 and SSC7. Imprinting analysis revealed a genome wise significant paternally expressed QTL on SSC2. A radiation hybrid (RH) map was constructed for SSC2. Comparison of the porcine RH map with homologous human chromosomes identified four conserved segments between SSC2 and HSA11, HSA19, and HSA5. To improve the existing comparative map for SSC2 and increase the gene density on this chromosome, a porcine BAC library was screened. Sequences from the BACs were compared with sequences in the nucleotide databases to identify homology with other mammalian sequences. For the investigation of the borders of the conserved segments between SSC2 and HSA11 genes located on HSA11 were mapped to SSC2. This resulted in refinement of the borders of the conserved segments and in the detection of a new rearrangement in the comparative map between HSA11 with the porcine genome. Through the use of radiation hybrid maps that include both Type I and II markers, homologous chromosomal locations for QTL of specific traits can be identified in other species. The conservation of genome organisation between pig, man and mouse makes it possible to take advantage of genetically well-characterised species for the selection of candidate genes for the imprinted QTL for backfat thickness on SSC2. Human obesity research can help to determine the direction and give clues for further porcine fat trait related genetic research, but emphasis should be on better understanding of the fat traits in pigs themselves and improvement of the genetic map of the pig.
Radiation induced sterility to control tsetse flies : the effect of ionising radiation and hybridisation on tsetse biology and the use of the sterile insect technique in integrated tsetse control
Vreysen, M.J.B. - \ 1995
Agricultural University. Promotor(en): J.C. van Lenteren; W. Takken. - S.l. : Vreysen - ISBN 9789054854432 - 282
sterilisatie - insecten - steriele insecten techniek - genetische gewasbescherming - vectorbestrijding - infectieziekten - anthomyiidae - muscidae - drosophilidae - calliphoridae - agromyzidae - tachinidae - glossinidae - tephritidae - glossina - schizophora - sterilization - insects - sterile insect release - genetic control - vector control - infectious diseases - anthomyiidae - muscidae - drosophilidae - calliphoridae - agromyzidae - tachinidae - glossinidae - tephritidae - glossina - schizophora
The induction of dominant lethal mutations by exposing tsetse flies as pupae or adult insects to ionising radiation and the use of hybrid sterility resulting from crosses of closely related tsetse species or subspecies, are potential methods of genetic control of tsetse flies. In this thesis the effects of radiation and hybridisation on the reproductive biology and fitness of several species of tsetse flies has been examined. In addition, aspects of field releases of sterile insects have also been examined.
|De gevleugelde missie van Thijs Loosjes.
Beekman, W. - \ 1994
Ekoland 14 (1994)12. - ISSN 0926-9142 - p. 20 - 21.
agromyzidae - allium cepa - anthomyiidae - nuttige insecten - biologische bestrijding - calliphoridae - drosophilidae - genetische gewasbescherming - glossinidae - insecten - muscidae - uien - steriele insecten techniek - sterilisatie - tachinidae - tephritidae - delia antiqua - schizophora - agromyzidae - allium cepa - anthomyiidae - beneficial insects - biological control - calliphoridae - drosophilidae - genetic control - glossinidae - insects - muscidae - onions - sterile insect release - sterilization - tachinidae - tephritidae - delia antiqua - schizophora
Interview with Thijs Loosjes, who runs a firm for biological control in agriculture. The firm is specialized in biocontrol of the onion fly by means of the sterile male technique
Translocations and sex ratio distortion in the onion fly, Hylemya antiqua (Meigen), and their relevance to genetic control
Vosselman, L. - \ 1980
Landbouwhogeschool Wageningen. Promotor(en): J. Sybenga. - Wageningen : Vosselman - 117
agromyzidae - anthomyiidae - calliphoridae - chromosoomtranslocatie - drosophilidae - genetische gewasbescherming - genetica - glossinidae - insecten - muscidae - geslacht (sex) - geslachtsbepaling - steriele insecten techniek - sterilisatie - tachinidae - tephritidae - stofverplaatsing - schizophora - agromyzidae - anthomyiidae - calliphoridae - chromosome translocation - drosophilidae - genetic control - genetics - glossinidae - insects - muscidae - sex - sex determination - sterile insect release - sterilization - tachinidae - tephritidae - translocation - schizophora
Experiments on sex determination of the onion fly, Hylemya antiqua (Meigen), are reported in the first two chapters. The main purpose was to establish if the sex ratio distortion observed in certain crosses, was based on a mechanism which could be used for genetic purposes. Two types of males, XY 1 and XXY 2 , were found and the aberrant sex ratios appeared only to occur in progenies of XXY 2 (and some XXY 2 Y 2 ) males. A numerical variation for Y 2 was frequently observed in embryos, larval ganglion cells and especially in testes, which is caused by numerical non-disjunction in somatic cells. The sex ratio distortion is attributed to such a numerical variation of Y 2 between primordial germ cells. Some progenies with a highly distorted sex ratio in male direction descended probably from XXY 2 Y 2 males. Since an effective selection of XXY 2 Y 2 males is not possible, this type of sex ratio distortion is not suited for application in a genetic control method. Other subjects treated in chapters 1 and 2 are gynandromorphism, a polymorphism with respect to the length of the X-chromosome and X-polysomy. In the progeny of one cross a chromosome morphologically identical to Y 2 but lacking its holandric inheritance was found. From its inheritance in various crosses it could be concluded that it was nothing more than a (mutated) non-functional Y 2 chromosome.The meiotic segregation of a Y 1 -linked translocation T61 is reported in the third chapter. The high percentage of alternate segregation observed in T61-heterozygous males (22 YXY 2) was in good accordance with the high fertility of this translocation (95%). Because of an early separation (or asynapsis) of the centromeric regions of the acrocentric X and Y 2, chain quadrivalents with X and Y 2in terminal position predominated in diakinesis/ prometaphase I stages. In these chain quadrivalents adjacent l is supposed to be unstable since neither X nor Y 2have a neighbouring centromere in trans-position. The very low frequency of adjacent 2 is attributed to a preferential coorientation of homologous centromeres. The suitability of T61 for genetic sexing (preferential killing of females) is discussed.Double-translocation heterozygous T14/T61 males (2 62 Y6 26XY 2) were produced by intercrossing T14-homozygous females (2 62 66 26 2XX) and T61-heterozygous males (22 Y66XY 2) These double heterozygotes showed several segregation types but for predominated. The total frequency of duplication/deficiency gametes was 60-65%. Application possibilities for these heterozygotes in genetic control of the onion fly are discussed.The meiotic segregation of five different autosomal reciprocal translocations are given in chapter 5. For translocation T14, which has very short interstitial segments, significant differences in segregation between the sexes were found. In males the ratio of alt.: adj.1:adj.2 was about 7:3:0 and in females 8:1:3. It is assumed that the very intimate meiotic pairing in males (without chiasmata) results in relatively very short "Coorientation Determining Distances" (CDD's) between the homologous centromeres. Due to these short CDD's a preferential coorientation between homologous centromeres is expected favouring alternate and adjacent l segregation. On the contrary, in females chiasmata act very probably as reference points for coorientation. Due to variable positions of the centromeres, in T14-heterozygous females less pronounced differences in CDD's between homologous and non-homologous are expected as in males. This is suggested to be the reason that in females a coorientation between non-homologous centromeres can occur resulting in a certain frequency of adjacent 2. The very low frequencies or absence of adjacent 2 in the other four translocations is attributed to their longer interstitial segments.For translocation T14 a pure breeding stock of homozygotes could be obtained using egg-hatch percentages and cytology for the recognition of the karyotypes (chapter 6). In cage experiments under laboratory conditions the competitiveness of the translocation homozygotes was tested. Starting from an initial population consisting of equal numbers of translocation homozygotes (TT) and wild type flies (++), the karyotype frequencies were determined for three successive, non-overlapping generations. The results obtained did not suggest substantial differences in fitness between TT and ++. In field cage experiments (chapter 7) a high diapause sensitivity was found for the translocation homozygotes as well as for the laboratory strain of wild type flies (++) used. As a consequence of this high diapause sensitivity the fitness of the homozygotes could not be determined under field conditions.In the "General Discussion" different application possibilities of translocations for genetic control of the onion fly are discussed. A summary of unpublished data concerning the egg-hatch and pupal survival of eight threechromosome double-translocation heterozygotes and three more complex translocation heterozygotes is also presented there. The aim of these experiments was to determine if perhaps a double translocation could be isolated meeting the conditions for a stable equilibrium. However, neither of these translocations met these conditions. Firstly, the frequencies of duplication/deficiency gametes were not high enough; secondly, insufficient complementation occurred and, thirdly, the recombination percentages in the differential segments were too high (resulting in undesirable karyotypes). Two of three double translocations tested, appeared to be viable as homozygotes in the adult stage.
|The use of ionizing radiation in agriculture : proceedings of a workshop, 22, 23 and 24 March 1976, Wageningen, The Netherlands
Stichting ITAL, ; Association Euratom, - \ 1977
Commission of the European Communities (Commission of the European Communities EUR 5815 en) - ISBN 9789282500576 - 566
agriculture - applications - effects - food irradiation - food preservation - genetic control - insects - isotopes - mutations - plant breeding - radiation - radioactivity - sterile insect release - sterilization - landbouw - toepassingen - effecten - voedselbestraling - voedselbewaring - genetische gewasbescherming - insecten - isotopen - mutaties - plantenveredeling - straling - radioactiviteit - steriele insecten techniek - sterilisatie
Aspects of gametogenesis and radiation pathology in th onion fly. Hylemya antigua (Meigen). II. Radiation pathology
Theunissen, J.A.B.M. - \ 1977
Wageningen : Veenman (Mededelingen Landbouwhogeschool Wageningen 77-12) - 132
agromyzidae - anthomyiidae - calliphoridae - drosophilidae - excretiestelsel - genetische gewasbescherming - glossinidae - insecten - muscidae - plantenplagen - voortplantingsorganen - steriele insecten techniek - sterilisatie - tachinidae - tephritidae - urogenitaalsysteem - delia antiqua - schizophora - agromyzidae - anthomyiidae - calliphoridae - drosophilidae - excretory system - genetic control - glossinidae - insects - muscidae - plant pests - reproductive organs - sterile insect release - sterilization - tachinidae - tephritidae - urogenital system - delia antiqua - schizophora
Ecology and genetic control of the onion fly, Delia antiqua (Meigen)
Loosjes, M. - \ 1976
Wageningen : Pudoc - 179
agromyzidae - allium cepa - diergedrag - anthomyiidae - calliphoridae - drosophilidae - ecologie - genetische gewasbescherming - glossinidae - gewoonten - insecten - muscidae - uien - steriele insecten techniek - sterilisatie - tachinidae - tephritidae - schizophora - agromyzidae - allium cepa - animal behaviour - anthomyiidae - calliphoridae - drosophilidae - ecology - genetic control - glossinidae - habits - insects - muscidae - onions - sterile insect release - sterilization - tachinidae - tephritidae - schizophora
Aspects of gametogenesis and radiation pathology in the onion fly, Hylemya antiqua (Meigen) : 1. Gametogenesis
Theunissen, J.A.B.M. - \ 1976
Landbouwhogeschool Wageningen. Promotor(en): J. de Wilde; L.P.M. Timmermans. - Wageningen : Veenman - 164
insecten - plantenplagen - anthomyiidae - muscidae - drosophilidae - calliphoridae - agromyzidae - tachinidae - glossinidae - tephritidae - sterilisatie - steriele insecten techniek - genetische gewasbescherming - excretiestelsel - voortplantingsorganen - urogenitaalsysteem - delia antiqua - schizophora - insects - plant pests - anthomyiidae - muscidae - drosophilidae - calliphoridae - agromyzidae - tachinidae - glossinidae - tephritidae - sterilization - sterile insect release - genetic control - excretory system - reproductive organs - urogenital system - delia antiqua - schizophora
In the scope of a genetic control research project gametogenesis of the onion fly, Hylemya antiqua (Meigen), is studied as a base for investigations on radiation histopathology of the gonads.Various cytological, histological, electronmicroscopical and autoradiographical methods, including investigation of living male germinal cells, are used.The gross anatomy of the male and female reproductive systems is simple as compared to other insect species.In newly hatched larvae the gonads contain on an average 13 germinal cells. Gonads in larvae which are less than 7 days old cannot be distinguished as being male or female. This distinction becomes possible after the apical cell and the apical somatic tissue respectively is formed in the young gonad.Spermatogenesis is treated in a number of paragraphs dealing with the description and identification of germinal and somatic cell types, the ontogenetic development of the testis, the dynamics of spermatogenesis and aspects of comparative spermatogenesis.A proper identification of the testicular cell types is considered to be imperative to any correct experimental approach of spermatogenesis. Morphological descriptions of the various germinal and somatic cell types are given accordingly. New elements are the observation of spermatogonial cells which show in their nucleus a varying degree of chromatin concentration. A similar phenomenon is observed in somatic cell types. Testicular cavities namely the apical cavities and the central cavity are described as are the somatic central cavity cells and the basal cells in the testis.The ontogenetic development shows the structure and function of the testis during the larval, pupal and adult stages of the life cycle. At the end of the larval stage differentiation of primary spermatogonia starts, leading to sperm production which takes place in the late pupa and the young adult. During adulthood the testis function changes from sperm production towards sperm storage.Based on counts of the number of cells per cyst of germinal cells it is supposed that various systems of spermatogonial multiplication operate in these populations. Primary spermatogonia may be denoted as being 'predefinitive' which indicates their presumed role in the multiplication processes. The number of definitive spermatogonial divisions may vary according to the acting multiplication system. The speed of formation of different spermatogenic cell types is revealed by incorporation of 3 H-thymidine in the spermatogonia. Development of a primary spermatogonium into sperm cells lasts about 10 days.Comparison of mainly morphological features of male germinal cell types in a number of insect species, including H. antiqua, indicates possibilities for comparative research of spermatogenesis in various insect species. This could provide a basis for comparative radiobiological or other experimental investigations on insect spermatogenesis.Female germinal cell types and somatic cell types of the ovary are described. The ontogenetic development of the ovary shows ovariole differentiation in the young pupal ovary. In late pupal ovaries egg chamber formation begins its iterative course which is continued during adulthood. Egg chamber formation has been divided into ten stages.Spermatogenesis and oogenesis share a number of features, which suggests a certain similarity of the processes involved.
Chromosal rearrangements in the onion fly Hylemya antiqua (Meigen), induced and isolated for genetic insect control purposes : studies on cytogenetics and fertility, with emphasis on an X-linked translocation
Heemert, C. van - \ 1975
Landbouwhogeschool Wageningen. Promotor(en): J. Sybenga. - Wageningen : [s.n.] - 83
agromyzidae - anthomyiidae - rassen (dieren) - calliphoridae - drosophilidae - genetische gewasbescherming - genetische variatie - glossinidae - overerving - insecten - muscidae - rassen (taxonomisch) - steriele insecten techniek - sterilisatie - tachinidae - tephritidae - schizophora - agromyzidae - anthomyiidae - breeds - calliphoridae - drosophilidae - genetic control - genetic variation - glossinidae - inheritance - insects - muscidae - races - sterile insect release - sterilization - tachinidae - tephritidae - schizophora
The aim of this investigation was to isolate structural chromosome mutations causing "semi"-sterility which can be used for genetic control of the onion fly Hylemya antiqua (Meigen). For the induction, X-rays or fast neutrons were applied in different doses on males and females. "Semi"-sterile families were screened cytologically for translocations and inversions. It appeared that high doses 0.5 krad of X-rays) tended to yield complex rearrangements which present difficulties in practical programs, in addition to the useful less complicated rearrangements. They also produce more genetic background damage than lower doses (0-5 krad), which still yield acceptable numbers of uncomplicated rearrangements and therefore are advised for a genetic control program. Because of strongly reduced fecundity of irradiated females these are less suitable for induction of rearrangements than males, although older females because of higher fecundity give better results than young females. Fast neutrons on young males were useful and a low dose of 0.25 krad appeared to be as good as 1.0 krad.Seventeen different translocations and two pericentric inversions were observed. Most "breakpoints" are located on the longer chromosome arms. Inversion heterozygous males were as fertile as the control which confirms their achiasmate meiosis. Eight translocation stocks were sibcrossed. In five of these, translocation homozygotes were found as larvae and in three out of these five even as adults. The occurrence of duplication/deficiency (from adjacent I orientation) larvae in the five stocks mentioned was remarkable.From experiments with an X-linked translocation it was concluded that the acrocentric chromosomes are the sex-chromosomes. The alternate and adjacent I orientation frequencies in translocation heterozygotes (X-linked) were shown to be equal in each sex, while no adjacent II was found. In this translocation meiotic numerical non- disjunction occurred in 18.7% of the tranlocation heterozygous females but in 2.0% of the males. This difference is probably a consequence of the difference in meiotic behaviour between the sexes. A good relationship was found between the degree of chromosomal unbalance and the frequency of late embryonic lethals (brown eggs) which was used as a graduator in the selection for "semi"-sterility.Adult fertile translocation trisomics and adult sterile tertiary trisomics were obtained (both sexes) after meiotic numerical non- disjunction. In translocation trisomic males the X-, Y- and translocated (extra) X-chromosome were shown to disjoin at random. In females the two normal X-chromosomes almost (95%) preferentially disjoin, while the translocated X-chromosome goes to either one of the poles. Primary trisomic males (XXY) and females (XXX) were obtained from testcrossed translocation trisomic parents. XXY males produced four types of gametes XY, X, Y and XX in equal numbers. XXX females only gave XX and X gametes in an equal number. Succesfull attempts to obtain homozygotes for this X-linked translocation are reported. The theoretical background of genetic insect control is discussed.