RESUMO
Wild species field cress (Lepidium campestre) has favorable agronomic traits, making it a good candidate for future development as an oil and catch crop. However, the species is very prone to pod shatter, resulting in severe yield losses. This is one of the important agronomic traits that needs to be improved in order to make this species economically viable. In this study, we cloned the L. campestre INDEHISCENT (LcIND) gene and prepared two LcIND-RNAi constructs with the IND promoter (long 400 bp and short 200 bp) from Arabidopsis. A number of stable transgenic lines were developed and evaluated in terms of pod shatter resistance. The majority of the transgenic lines showed increased resistance to pod shatter compared to the wild type, and this resistance was maintained in four subsequent generations. The downregulation of the LcIND gene by RNAi in the transgenic lines was confirmed by qRT-PCR analysis on T3 lines. Southern blot analysis showed that most of the analyzed lines had a single-copy integration of the transgene, which is desirable for further use. Our results show that it is possible to generate stable transgenic lines with desirable pod shatter resistance by downregulating the LcIND gene using RNAi in field cress, and thus speeding up the domestication process of this wild species.
Assuntos
Arabidopsis , Brassicaceae , Lepidium , Lepidium/genética , Interferência de RNA , Regulação para Baixo , Brassicaceae/genética , Arabidopsis/genética , Plantas Geneticamente Modificadas/genéticaRESUMO
There is an assumption in current landscape preference theory of universal consensus in human preferences for moderate to high openness in a natural landscape. This premise is largely based on empirical studies of urban Western populations. Here we examine for the first time landscape preference across a number of geographically, ecologically and culturally diverse indigenous populations. Included in the study were two urban Western samples of university students (from southern Sweden) and five non-Western, indigenous and primarily rural communities: Jahai (Malay Peninsula), Lokono (Suriname), Makalero (Timor), Makasae (Timor), and Wayuu (Colombia). Preference judgements were obtained using pairwise forced choice assessments of digital visualizations of a natural landscape varied systematically on three different levels of topography and vegetation density. The results show differences between the Western and non-Western samples, with interaction effects between topography and vegetation being present for the two Swedish student samples but not for the other five samples. The theoretical claim of human preferences for half-open landscapes was only significantly confirmed for the student sample comprising landscape architects. The five non Western indigenous groups all preferred the highest level of vegetation density. Results show there are internal similarities between the two Western samples on the one hand, and between the five non-Western samples on the other. To some extent this supports the idea of consensus in preference, not universally but within those categories respectively.
RESUMO
Transgenic Pseudomonas fluorescens 5-2/4 with reinforced 2,4-diacetyl phloroglucinol (phl) production had shown increased biocontrol ability towards Pythium ultimum (Pu), but inferior root colonization ability compared to its wild type 5.014. Therefore, enhanced root colonization ability of the transgenic strain by repeated inoculation and reisolation on tomato plants was suggested. As a preparation for repeated inoculation and reisolation cycles, the construction of a negative control of the transgenic strain 5-2/4 by marking with lacZY and screening for a mutant possessing qualities comparable to 5-2/4 was performed. Morphologically, colonies of all of the 11 selected mutants were similar on MLXgal medium. The root colonization ability of two of the lacZY-marked strains (mutants 1 and 10) was comparable to the parental strain. These were also able to compete with the resident microflora of tomato seedlings to the same extent as the parental strain. Five mutants were excluded due to lower growth rates on Yeast Malt, King's B Medium (KB) and 0.1 Tryptic Soy Agar (mutant 4, 5 and 8), excessive growth and higher siderophore production on KB (mutant 10) and increased protease production (mutant 2). With respect to in vitro-antagonism of Pu, no differences could be found between the target strain and mutants 1, 3, 6, 7 and 9. Examination of sole carbon source utilization of these five lacZY-marked strains revealed a significantly higher utilization of alpha-D-lactose and lactulose compared to 5-2/4. However, significant differences could be found for 51% of the utilized carbon sources. Cluster analysis showed a high degree of similarity between 5-2/4 and mutant 1 both when analyzed with and without alpha-D-lactose. As mutant 1 also represented the colonization pattern most similar to the parental strain 5-2/4, it presents a presumptive subject for a negative control in the following inoculation and reisolation studies on tomato.
Assuntos
Proteínas de Escherichia coli , Proteínas de Transporte de Monossacarídeos , Floroglucinol/metabolismo , Raízes de Plantas/microbiologia , Pseudomonas fluorescens/fisiologia , Solanum lycopersicum/microbiologia , Simportadores , Carbono/farmacologia , Marcadores Genéticos , Óperon Lac/genética , Lactose/metabolismo , Lactulose/metabolismo , Solanum lycopersicum/genética , Proteínas de Membrana Transportadoras/genética , Mutação , Controle Biológico de Vetores , Floroglucinol/análogos & derivados , Pseudomonas fluorescens/efeitos dos fármacos , Pseudomonas fluorescens/genética , Pythium/crescimento & desenvolvimento , Sideróforos/metabolismoRESUMO
BACKGROUND: Pollen beetle is a pest that attacks oilseed rape as well as many other brassicaceous crops, garden vegetables and ornamental flowers. The present study was primarily carried out to investigate whether insecticide application in brassicaceous field crops might influence the abundance of pollen beetles in nearby private garden flowers and vegetables. RESULTS: At peak emergence of the new generation of pollen beetles, a significantly higher number of beetles were found in flowers, and in window traps, alongside untreated as opposed to alongside treated sections of the winter oilseed rape (WOSR) field. However, the type of flower played a role in the number of pollen beetles found in the flowers. The presence of pollen beetles in both ornamental and wild flowers was also significantly influenced by the direction of placement of the flowers. No pollen beetle, neither overwintering nor newly emerged, was observed in any of the brassicaceous vegetables placed along the field. CONCLUSION: The number of pollen beetles in the WOSR field strongly influenced the number of pollen beetles in nearby flowers of preference to the beetles, and insecticide treatment with Biscaya (thiacloprid) against pollen beetle in oilseed rape may thus help, indirectly, to protect nearby garden flowers from damage.
Assuntos
Brassica napus/parasitologia , Besouros/efeitos dos fármacos , Flores/parasitologia , Inseticidas/farmacologia , Doenças das Plantas/prevenção & controle , Verduras/parasitologia , Animais , Besouros/fisiologia , Neonicotinoides , Controle de Pragas , Doenças das Plantas/parasitologia , Piridinas/farmacologia , Estações do Ano , Tiazinas/farmacologiaRESUMO
Public concern about pesticide use is high although varying with social factors. Individual differences in 'perception' and attitude to pesticide use might be particularly evident in periurban regions where farmers and other people live together. This was investigated using a questionnaire sent to 600 farmers and 600 non-farmers in two periurban areas of Sweden. 'Neighbors'(1) were found to have a more negative attitude to pesticides than farmers, who were slightly positive to the use. Neighbors perceived pesticide use in agriculture to be more harmful to the environment than did farmers and also to reduce the quality of products. Both farmers and neighbors thought that farmers are the predominant users of pesticides. However, reported pesticide users within the home setting were just as common among the neighbors as among the farmers. Perceptions of pesticide use were also found to differ between periurban regions within the country. Attitudes and perceptions of pesticide use, as well as of who is the user, differ based on the group of people in a periurban environment and between different regions. Such differences might play a role for tensions and conflicts in the periurban area of a society and also for regulations of pesticide use.