Many plant species recognize kin and respond with changes in functional traits. Researchers hypothesize that siblings compete less than strangers. However, no study has directly tested whether siblings are less competitive. Measuring natural selection on kin recognition responses in root allocation and other destructively measured traits is challenging, since trait and fitness cannot be measured on the same individual. Here, a methodology using family-level selection is developed, measuring the trait on one individual and measuring its fitness value using another related individual. Three greenhouse pot experiments were conducted using six Brassica oleracea cultivars at two nutrient levels. We investigated whether root allocation and morphological traits were under natural selection. We tested whether or not there was cultivar recognition or resource partitioning in B. oleracea. We found that putative competitive traits (size, height, emergence and root allocation) had expected patterns of individual selection for an increase in each trait and group selection for a reduction of each trait. There was no indication that resource partitioning was occurring or that B. oleracea could recognize cultivars. However, plants were experiencing competitive interactions within pots. In conclusion, we demonstrate that using family-level selection estimates the fitness consequences of root allocation and morphological traits. / Thesis / Master of Science (MSc)

Hyperparasitism of beneficial parasites of Pieris rapae was studied on Brassica crops in Montgomery County, Virginia. The goal of the study was to determine whether the hyperparasites attacking the larval parasites of P. rapae were capable of eliminating an introduced population of the larval parasite Cotesia rubecula (Marshall) (Hymenoptera: Braconidae). Pieris rapae was found to be active from April to November with possibly six generations per year in this region. It was attacked throughout this period by five generations of the larval parasite Cotesia glomerata (L.) (Hymenoptera: Braconidae). Although P. rapae larvae were twice as numerous on broccoli (var. Premium Crop) than on cabbage (var. Rio Verde), a higher proportion of P. rapae larvae was parasitized by C. glomerata on cabbage, indicating that C. glomerata preferred to forage for P. rapae in cabbage. In spring plantings, up to 36.9% of C. glomerata cocoon masses had been affected by the hyperparasite T. galaetopus (Ratzeburg) (Hymenoptera: (Eulophidae) and 23.3% by the hyperparasite Spiloehaleis torvina Cresson (Hymenoptera: Chalcididae). In the fall, 93.2% and 4.2% of the cocoon masses were affected by T. galaetopus and S. torvina, respectively. Tetrastiehus galaetopus activity was observed from May to November, but it was most active after mid July. Tetrastiehus ga/aetopus had little impact on the gregarious C. glomerata, and even though it could affect >90% of the C. glomerata cocoon masses for extended periods, 500/0 of the cocoons in each mass were unaffected. However, it's high reproductive capacity could adversely affect a solitary host such as C. rubecula. Spilochalcis torvina was observed as early as late May but it was most active during the mid summer months. It's reproductive activity ceased by early October even though hosts were abundant in the month which followed. Four generations were seen between June and October. Spilochalcis torvina's hosts were Cotesia orobenae Forbes (Hymenoptera: Braconidae), C. glomerata, and Plutella xylostella (L.) (Lepidoptera: Plutellidae), but the principal host was C. glomerata. However, the proportion of female S. torvina progenies was <31% from the Cotesia spp. hosts and 70% from P. xylostella hosts. Spilochalcis torvina typically hyperparasitized <4 pupae per Cotesia spp. cocoon mass in the field. In laboratory experiments, S. torvina hyperparasitized an average of <7 C. rubecula pupae daily, and the maximum number hyperparasitized was 12. Due to its apparently low reproductive rate in the laboratory, and its low rate of hyperparasitization on hosts in the field, it is unlikely that S. torvina is a danger to populations of parasites like C. rubecula. / Master of Science

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Made available in DSpace on 2017-07-25T19:30:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-02-22 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / Sclerotinia sclerotiorum infect many plants, including crops of great economic importance as soybeans (Glycine max) and oilseed rape (Brassica sp.), responsible for great losses. The plant disease control is the most important practical objective of plant pathology, but the correct and rapid diagnosis are essential to define strategies for the diseases management. Molecular techniques are able to amplify specific fragments from small amounts of genetic material and powerful tools widely used in various areas, including the phytopathological diagnosis. Several techniques have been studied and designed for the amplification of nucleic acids, including the LAMP (Loop-mediated isothermal amplification), which has high specificity, sensitivity and is fast. The aim of this study was to develop and optimize a specific molecular test for S. sclerotiorum by LAMP, as well as its validation to oilseed pare and soybean seeds samples. A set of six primers was designed and evaluated for S. sclerotiorum sensitivity and specificity detection. The composition of the LAMP reaction was enhanced for real-time (SS-qLAMP) and direct analysis (SS-cLAMP). The DNA from 57 isolates of S. sclerotiorum, DNA from several other plant pathogens and DNA from different cultures was tested. The DNA of all isolates of S. sclerotiorum were detected but no the other DNA samples. When testing the limit of detection of reactions, a single copy detections was suggested. By SS-qLAMP two curves were generated which can be used to estimate the amount of mycelium and DNA of S. sclerotiorum present in the samples analyzed. Bothe developed tests (SS-qLAMP and SS-cLAMP) can be applied to several purposes, such as detection of the pathogen in plant, spore traps, soil and seeds samples. Using seed samples with different contamination level, the test was optimized for canola and soybean seeds, SS-qLAMP(Canola) and SS-qLAMP(Soybean), respectively, detecting the presence of the pathogen in samples up to 0.13% and 0.03% naturally contaminated for canola and soybean, respectively, and was able to detect contamination in samples not contaminated according incubation-based methods. The time require for the test was 4h and 30 minutes and 2 hours and 50 minutes for canola and soybeans, respectively, with no needs of large space for samples incubation, specialized analysts and able to analyzed many samples simultaneously. The proposed method SS-qLAMP was well-validated according the ISTA (International Seed Testing Association) rules to oilseed-rape and soybean seed samples. x / Sclerotinia sclerotiorum é um fungo que pode atacar diversas espécies vegetais, incluído culturas de grande importância econômica como soja (Glycine max) e canola (Brassica sp.), causando grandes prejuízos para as mesmas. O controle de doenças de plantas é o mais importante objetivo prático da Fitopatologia, mas, a correta e rápida diagnose da doença são pré-requisitos indispensáveis para definir as medidas para o manejo das mesmas. Técnicas moleculares capazes de amplificar fragmentos específicos a partir de pequenas quantidades de material genético são poderosas ferramentas amplamente utilizadas em diversas áreas, incluindo o diagnóstico fitopatológico. Diversas técnicas têm sido estudadas e criadas para a amplificação de ácidos nucleicos, entre elas a LAMP (Amplificação isotérmica mediada por “loops”), que apresenta alta especificidade, sensibilidade e é rápida. O objetivo do presente estudo foi desenvolver e otimizar um teste molecular específico para S. sclerotiorum a base de LAMP, com obtenção de resultados em tempo real e quantitativos (qLAMP) e análise visual direta de resultados (cLAMP), assim como a validação do mesmo para ser utilizado na análise de amostras de sementes de canola e soja. Um conjunto de seis primers foi desenhado e avaliado quanto a sensibilidade e especificidade de detecção de S. sclerotiorum. A composição da reação de LAMP foi otimizada quanto a concentração de diversos componentes tanto para a análise em tempo real como direta, compondo, respectivamente as reações de SS-qLAMP e SS-cLAMP, conforme necessário. Testou-se o DNA de 57 isolados de S. sclerotiorum, o DNA de diversos outros fitopatógenos e o DNA de diversas culturas. O DNA de todos os isolados de S. sclerotiorum foram detectados mas não o de outros fitopatógenos e de plantas. Ao testar o limite de detecção das reações, não houve um limite de detecção, sugerindo que a presença de qualquer molécula de DNA alvo seria detectada. Pelo método quantitativo foi possível gerar duas curvas pelas quais pode-se estimar a quantidade de micélio e de DNA de S. sclerotiorum presente na amostra analisada. Desenvolveu-se um teste específico para S. sclerotiorum a base de LAMP, denominada SS-LAMP que pode ser aplicado em diversos casos, como a detecção do patógeno em amostras de plantas, armadilhas de esporos, de solo e sementes. Otimizou-se o teste SS-LAMP para sementes de canola e soja, SS-qLAMP(Canola) e SS-qLAMP(Soja), respectivamente, detectando-se a presença do patógeno em amostras com até 0,13% e 0,03% de contaminação natural, para canola e soja, respectivamente, além da detecção em amostras que os métodos tradicionais não detectaram. O tempo total do método foi de 4h e 30 minutos para canola e 2h e 50 minutos para soja, sem a necessidade de amplo espaço para incubação das amostras, pessoal especializado para análise e com a possibilidade de diversas amostras serem analisadas concomitantemente. Assim validou-se o método proposto SS-qLAMP(Soja) segundo as regras da ISTA (International Seed Testing Association – Associação Internacional de Análise de Sementes).

Nabis kinbergii is a native polyphagous predator in Australia. It has been found in all states and territories of Australia. N. kinbergii has been regarded as an efficient predator of many insect pests in lucerne, cotton and particularly brassica crops. The circadian rhythms, the effects of different prey on development and reproduction, and prey preferences of N. kinbergii have not been studied in South Australia. These are the subjects of this thesis. N. kinbergii is more active at night than in the day. They seemed to be still more frequently at dawn and more active at dusk under natural environmental conditions. Yet, their behaviour was possibly different when they were held in a controlled environment with artificial light. Under both natural and artificial lighting conditions, they would spend more time moving on plants at night. They spent less time moving than other activities. Furthermore, they were more active during the second day of the observations, probably because of the hunger. A mixed diet including Plutella xylostella, Myzus persicae and Brevicoryne brassicae brought the most significant positive influences to the development, survival and longevity of N. kinbergii. It had a shorter preoviposition period and greater egg production when fed on P. xylostella than when fed on M. persicae. Among the three prey, B. brassica was the poorest food because the survival rate between egg hatch and adult eclosion was only 7.5 %, compared to 85 %, 92.5 % and 97.5 % when N. kinbergii fed on M. persicae, P. xylostella and a mixed diet, respectively. Evidence of prey preference was exhibited by N. kinbergii. B. brassica seemed to be the least preferred food. N. kinbergii possibly attacked less mobile prey and delayed eating prey with poor nutrition or that were toxic. In wind tunnel experiments, N. kinbergii may have been attracted by plant volatiles rather than prey odour. These findings may help to refine the timing of experiments and improve the understanding of the role of this predator in integrated pest management. / Thesis (M.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

La phytoremédiation constitue une nouvelle technologie permettant de dépolluer les sols contaminés par l'utilisation de plantes. Parmi les différents aspects possibles de cette méthode, figure la phytoextraction basée sur l'absorption et l'accumulation du polluant dans les parties aériennes. Pour être efficace, il est nécessaire de disposer de plantes présentant une biomasse élevée. L'objectif de ce travail visait à sélectionner des variétés de moutarde indienne (Brassica juncea L.) tolérantes et accumulatrices de cadmium.<br />La première partie du travail a consisté à mettre au point et à optimiser une méthode de régénération in vitro de plantes de moutarde indienne, à partir de couches cellulaires minces transversales (CCMTs) (influence de l'organe utilisé, de AgNO3 et de la benzylaminopurine). La régénération a été réalisée en appliquant une pression de sélection par le cadmium pour modifier la tolérance au métal. <br />La deuxième partie aborde l'effet des traitements par le cadmium : in vitro et en serre, sur le développement des plants. Une analyse des perturbations physiologiques et biochimiques observées a permis d'évaluer la tolérance des plants vis à vis du cadmium et indiquent que les plantes néoformées en présence de cadmium mettent en place un système d'exclusion du métal.<br />Dans la troisième partie, pour compléter l'étude précédente sur des plantes néoformées, l'effet du cadmium a été testé sur des plantes de B. juncea directement issues de semis. Plusieurs paramètres physiologiques et biochimiques, caractéristiques des stress, ont été étudiés (activité gaïacol peroxydase, peroxydation des lipides, pigments, acides aminés libres, proline glucides, polyamines libres et conjuguées). En raison de leurs propriétés anti-oxydantes, une attention particulière a été portée aux polyamines dont l'application exogène permet d'envisager son utilisation pour améliorer la capacité d'accumulation du cadmium par les plantes.

L'intérêt pour la dispersion des gènes via le pollen a augmenté avec les cultures de plantes génétiquement modifiées. A ce jour, les données expérimentales ainsi que la modélisation portant sur les mouvements du pollen de colza, Brassica napus L., à l'échelle du paysage ne différencie pas clairement la part du vent et des insectes dans cette dispersion. Cependant, l'estimation de la dispersion des gènes par le pollen reste une condition nécessaire pour la gestion des risques d'échappement des (trans-)gènes vers l'environnement et les cultures conventionnelles. A travers cette thèse, nous avons pu mettre en évidence qu'une grande diversité d'insectes pollinisateurs pouvait transporter du pollen viable entre différentes plantes de colza sur des distances importantes (>1.1 km). La diversité d'insectes varie d'une région à l'autre et d'une année sur l'autre. Cependant, bien que la majorité des insectes sur une zone de grande production de colza ait du pollen de cette culture sur leur corps, seulement 39,4 % des insectes capturés sur des plantes mâle-stériles transportent du pollen de colza viable. Bien que nous n'ayons pas pu déterminer avec précision la part du vent et des insectes dans le pollinisation du colza, il semblerait que les insectes participent de façon plus importante à la pollinisation de plantes présentes en bordures de champs, augmentant ainsi le taux de pollinisation croisée. Nos résultats fournissent des données fiables pour améliorer les modèles de dispersion pollinique pour des cultures entomophiles à l'échelle du paysage. Ces modèles sont essentiels pour l'aide à la gestion afin de réduire la dispersion des gènes par le pollen des cultures génétiquement modifiées vers les plantes sauvages ou les cultures conventionnelles

<p>Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in <i>Raphanus raphanistrum</i>. The results showed that there exists a possibility for pollinator-mediated short-term evolution of flower size in the study species. Flower size was strongly correlated to plant size. Since flower size cannot evolve separately from plant size, this correlation may constitute a constraint to the evolution of flower size. The second aim was to determine how varying pollen load affects later flowering, reproduction and growth of maternal plants. High pollen load treatment resulted in larger or more flowers on late flowers, which may enhance pollen dispersal and reproductive success, while the total seed mass was the same between treatments. The results indicate that the study species <i>R. raphanistrum</i>, <i>Sinapis arvensis</i> and <i>Brassica napus</i> have plastic responses in floral traits according to the present pollination level. The third aim was to determine how varying pollen load affects seed quality and offspring vigor. The results suggest that high pollen load had no positive effects on seed quality or offspring vigor due to pollen competition. Instead, seed mass determined seed quality and offspring vigor in the three study species and low pollen load treatment resulted in highquality offspring due to heavier seeds. The fourth aim was to examine causes and consequences of variation in reproductive success of <i>Succisa pratensis</i> on a regional scale. The results suggest that the most important variables, on a regional scale, for reproductive success were population size and habitat quality. The results showed that seed weight variation might be important when assessing reproductive success. In this study, seed weight variation did not seem to be adaptive.</p>

Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in Raphanus raphanistrum. The results showed that there exists a possibility for pollinator-mediated short-term evolution of flower size in the study species. Flower size was strongly correlated to plant size. Since flower size cannot evolve separately from plant size, this correlation may constitute a constraint to the evolution of flower size. The second aim was to determine how varying pollen load affects later flowering, reproduction and growth of maternal plants. High pollen load treatment resulted in larger or more flowers on late flowers, which may enhance pollen dispersal and reproductive success, while the total seed mass was the same between treatments. The results indicate that the study species R. raphanistrum, Sinapis arvensis and Brassica napus have plastic responses in floral traits according to the present pollination level. The third aim was to determine how varying pollen load affects seed quality and offspring vigor. The results suggest that high pollen load had no positive effects on seed quality or offspring vigor due to pollen competition. Instead, seed mass determined seed quality and offspring vigor in the three study species and low pollen load treatment resulted in highquality offspring due to heavier seeds. The fourth aim was to examine causes and consequences of variation in reproductive success of Succisa pratensis on a regional scale. The results suggest that the most important variables, on a regional scale, for reproductive success were population size and habitat quality. The results showed that seed weight variation might be important when assessing reproductive success. In this study, seed weight variation did not seem to be adaptive.

Compatible interactions between male gametophytes (pollen) and the female reproductive organ (pistil) are essential for fertilization in flowering plants. Recognition at a molecular level allows “compatible” pollen grains to adhere/germinate on the stigma while pollen grains from unrelated plant species are largely ignored. The exocyst is a large eight subunit complex that is primarily involved in polarized secretion or regulated exocytosis in eukaryotic cells where it functions to tether vesicles to the plasma membrane. Recent research has implicated one of the Exo70 family members, Exo70A1, in compatible pollen-pistil interactions in Arabidopsis and Brassica. The loss of Exo70A1 in Arabidopsis Col-0 stigmas leads to the rejection of compatible pollen producing a “female sterile” phenotype. Through my research I have demonstrated that, driven by a stigma-specific promoter, an RFP:Exo70A1 fusion protein rescues this defect in exo70A1-1 mutant and Exo70A1 is found to be localized to the plasma membrane at flower opening.