The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera littoralis and Agriotes spp.
A plant's defensive ability against herbivore attack can be influenced by many different factors, one of them being domestication. During human selection to improve the yield of plants, the resistance against herbivore attack can have been lowered, due to a trade-off for use of resources between the...
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| Formato: | H2 |
| Lenguaje: | Inglés sueco |
| Publicado: |
SLU/Dept. of Plant Breeding (from 130101)
2014
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| Materias: |
| _version_ | 1855571168771178496 |
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| author | Sjöstrand, Joakim |
| author_browse | Sjöstrand, Joakim |
| author_facet | Sjöstrand, Joakim |
| author_sort | Sjöstrand, Joakim |
| collection | Epsilon Archive for Student Projects |
| description | A plant's defensive ability against herbivore attack can be influenced by many different factors, one of them being domestication. During human selection to improve the yield of plants, the resistance against herbivore attack can have been lowered, due to a trade-off for use of resources between these traits in the plants.
In this thesis I investigated the effect of domestication on resistance against herbivorous insects in cotton plants. I used different varieties and species of wild and domesticated cotton in three different experiments. A feeding assay was conducted, the mortality, development
time and pupal weight of larvae of the Egyptian cotton leaf worm Spodoptera littoralis was studied. In a second experiment the preference of the root-feeding beetle Agriotes spp. was monitored in a two choice assay comparing domesticated cotton to other cotton varieties and species. The third part of the thesis was an odour collection from domesticated cotton plants induced by either S. littoralis larvae feeding on the leaves, Agriotes spp. feeding on the roots or a combination of damage from both species.
The data show that there is a difference between cotton cultivars and that wild varieties delay development time compared to domesticated cotton. The feeding assay showed that the domesticated varieties Dpl 90 and Glandless cotton had significantly shorter development times than the undomesticated varieties (Tx 263, Tx 2259 and G. herbaceum) The two choice assay with Agriotes spp. larvae did not give any significant results most likely because of a low number of repetitions. Agriotes spp. did not prefer either domesticated nor undomesticated varieties of cotton. However, a trend in favor of the domesticated cotton
variety could be observed.
Finally, analysis of the odour collection demonstrates that plants induced by Spodoptera littoralis alone release higher amounts of the volatiles alpha pinene, 1S-beta pinene, myrcene and terpinolene than plants induced with either only Agriotes spp. or a combination of the two types of larvae. It may be that Agriotes spp. can manipulate the defence of the cotton plants. Another explanation is that the cotton plants cannot detect the Agriotes larvae. Also,
there might have been a release of volatiles below ground that was not detected due to the layout of the experiment. |
| format | H2 |
| id | RepoSLU7350 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2014 |
| publishDateSort | 2014 |
| publisher | SLU/Dept. of Plant Breeding (from 130101) |
| publisherStr | SLU/Dept. of Plant Breeding (from 130101) |
| record_format | eprints |
| spelling | RepoSLU73502014-09-25T10:42:13Z The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera littoralis and Agriotes spp. Effekten av domesticering på insektsresistens i bomull : bioassays med Spodoptera littoralis och Agriotes spp. Sjöstrand, Joakim Spodoptera littoralis Agriotes lineatus insect resistance cotton gossypium A plant's defensive ability against herbivore attack can be influenced by many different factors, one of them being domestication. During human selection to improve the yield of plants, the resistance against herbivore attack can have been lowered, due to a trade-off for use of resources between these traits in the plants. In this thesis I investigated the effect of domestication on resistance against herbivorous insects in cotton plants. I used different varieties and species of wild and domesticated cotton in three different experiments. A feeding assay was conducted, the mortality, development time and pupal weight of larvae of the Egyptian cotton leaf worm Spodoptera littoralis was studied. In a second experiment the preference of the root-feeding beetle Agriotes spp. was monitored in a two choice assay comparing domesticated cotton to other cotton varieties and species. The third part of the thesis was an odour collection from domesticated cotton plants induced by either S. littoralis larvae feeding on the leaves, Agriotes spp. feeding on the roots or a combination of damage from both species. The data show that there is a difference between cotton cultivars and that wild varieties delay development time compared to domesticated cotton. The feeding assay showed that the domesticated varieties Dpl 90 and Glandless cotton had significantly shorter development times than the undomesticated varieties (Tx 263, Tx 2259 and G. herbaceum) The two choice assay with Agriotes spp. larvae did not give any significant results most likely because of a low number of repetitions. Agriotes spp. did not prefer either domesticated nor undomesticated varieties of cotton. However, a trend in favor of the domesticated cotton variety could be observed. Finally, analysis of the odour collection demonstrates that plants induced by Spodoptera littoralis alone release higher amounts of the volatiles alpha pinene, 1S-beta pinene, myrcene and terpinolene than plants induced with either only Agriotes spp. or a combination of the two types of larvae. It may be that Agriotes spp. can manipulate the defence of the cotton plants. Another explanation is that the cotton plants cannot detect the Agriotes larvae. Also, there might have been a release of volatiles below ground that was not detected due to the layout of the experiment. Växters förmåga att försvara sig varierar beroende på många olika orsaker. En teori säger att domesticeringen av vissa växter har sänkt deras resistens mot herbivorer i en trade-off med andra egenskaper så som ökad skörd som människan selekterat fram. I det här arbetet har jag undersökt effekten av domesticering på resistensen mot växtätande insekter genom att använda sorter och arter av bomull i olika stadier av domesticering. Detta har gjorts i tre olika experiment. Först genomfördes ett utvecklingsexperiment i vilket jag studerade utvecklingen av larver av bomullsflyet, Spodopeta littoralis från ägg till förpuppning, samt puppornas vikt. Den andra delen var ett beteendeförsök där rotlevande larver från skalbaggarna Agriotes spp. fick välja mellan rotsystemen av olika bomullsplantor. En tredje del av arbetet var en insamling av växtdofter från bomullsplantor som inducerats antingen av S. littoralis, som ätit på bladen, Agriotes spp., som ätit på rötterna eller en kombination av skadorna från båda arterna. Mina data visar att det finns en skillnad mellan olika bomullssorter och att vildare sorter generellt har en högre resistens mot insektsangrepp än domesticerade sorter. De domesticerade sorterna Dpl 90 och glandless cotton gav en signifikant kortare utvecklingstid i utvecklingsexperimentet än de vilda sorterna Tx263, G. herbaceum och Tx 2259. Däremot var det inga signifikanta skillnader mellan bomullssorterna i vikten på pupporna mellan dieterna. Tvåvalstestet med Agriotes-larver gav inga signifikanta resultat vilket troligen berodde på ett för lågt antal av replikat. Jag fann dock en tydlig trend där larverna föredrog den domesticerade sorten Dpl 90 över alla andra testade sorter, förutom den vilda arten G.herbaceum. Analysen av insamling av växtdofter visar att plantorna som inducerats av S. littoralis reagerar starkare och har en högre avgivning av flyktiga ämnen såsom alpha pinene, 1S-beta pinene, myrcene och terpinolene än plantor som inducerats av endast Agriotes spp. eller med en kombination av de båda arterna. Möjligtvis kan Agrioteslarverna manipulera bomullsplantan så att den inte startar sitt inducerade försvar eller så kan bomullsplantan inte upptäcka dem. Möjligen har också flyktiga ämnen släppts ut från rötterna av bomullsplantorna vilket inte detekterats eftersom endast ämnen från överjordiska delar insamlades. SLU/Dept. of Plant Breeding (from 130101) 2014 H2 eng swe https://stud.epsilon.slu.se/7350/ |
| spellingShingle | Spodoptera littoralis Agriotes lineatus insect resistance cotton gossypium Sjöstrand, Joakim The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera littoralis and Agriotes spp. |
| title | The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera
littoralis and Agriotes spp. |
| title_full | The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera
littoralis and Agriotes spp. |
| title_fullStr | The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera
littoralis and Agriotes spp. |
| title_full_unstemmed | The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera
littoralis and Agriotes spp. |
| title_short | The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera
littoralis and Agriotes spp. |
| title_sort | effect of domestication on insect resistance in cotton : bioassays with the insect herbivores spodoptera
littoralis and agriotes spp. |
| topic | Spodoptera littoralis Agriotes lineatus insect resistance cotton gossypium |