Changes in the environmental conditions experienced by naturally occurring populations are frequently accompanied by changes in adaptive traits allowing the organ- ism to cope with environmental unpredictability. Phen...Changes in the environmental conditions experienced by naturally occurring populations are frequently accompanied by changes in adaptive traits allowing the organ- ism to cope with environmental unpredictability. Phenotypic plasticity is a major aspect of adaptation and it has been involved in population dynamics of interacting species. In this study, phenotypic plasticity （i,e., environmental sensitivity） of morphological adap- tive traits were analyzed in the cactophilic species Drosophila buzzatii and Drosophila koepferae （Diptera： Drosophilidae） considering the effect of crowding conditions （low and high density）, type of competition （intraspecific and interspecific competition） and cacti hosts （Opuntia and Columnar cacti）. All traits （wing length, wing width, thorax length, wing loading and wing aspect） showed significant variation for each environmental factor considered in both Drosophila species. The phenotypic plasticity pattern observed for each trait was different within and between these cactopbilic Drosophila species depending on the environmental factor analyzed suggesting that body size-related traits respond almost independently to environmental heterogeneity. The effects of ecological factors analyzed in this study are discussed in order to elucidate the causal factors investigated （type of com- petition, crowding conditions and alternative host） affecting the election of the breeding site and/or the range of distribution of these cactophilic species.展开更多
Aphids （Hemiptera： Aphididae） are phytophagous insects that are important agricultural pests. The enormous negative economic impacts caused by aphids worldwide are well known, and are mostly due to their high multi...Aphids （Hemiptera： Aphididae） are phytophagous insects that are important agricultural pests. The enormous negative economic impacts caused by aphids worldwide are well known, and are mostly due to their high multiplication rate and the transmission of phytopathogenic viruses. Aphid management strategies mainly involve chemical treatments which are pollutants and are increasingly inefficient, since aphids have developed multiple insecticide-resistant mechanisms. Among the most economically important species is the green peach aptfid Myzus persicae Sulzer （Aphididae： Macrosiphini）, which is able to colonize a wide range of host plants belonging to many different families, and transmits numerous plant viruses. Because of its large prevalence, M. persicae has been the target of massive insecticide treatments; consequently, it has evolved several insecticide-resistant mechanisms. In this work, a collection of expressed genes from M. persicae is presented in order to identify putative genes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959 expressed sequence tags （EST） were annotated. Most sequences matched known genes corresponded to metabolism proteins （26%）, ribosomal proteins （ 23 % ） and structural proteins （8%）. Among them, several sequences corresponded to proteins putatively involved in sensing, degradation or detoxification of plant xenobiotic products.展开更多
文摘Changes in the environmental conditions experienced by naturally occurring populations are frequently accompanied by changes in adaptive traits allowing the organ- ism to cope with environmental unpredictability. Phenotypic plasticity is a major aspect of adaptation and it has been involved in population dynamics of interacting species. In this study, phenotypic plasticity （i,e., environmental sensitivity） of morphological adap- tive traits were analyzed in the cactophilic species Drosophila buzzatii and Drosophila koepferae （Diptera： Drosophilidae） considering the effect of crowding conditions （low and high density）, type of competition （intraspecific and interspecific competition） and cacti hosts （Opuntia and Columnar cacti）. All traits （wing length, wing width, thorax length, wing loading and wing aspect） showed significant variation for each environmental factor considered in both Drosophila species. The phenotypic plasticity pattern observed for each trait was different within and between these cactopbilic Drosophila species depending on the environmental factor analyzed suggesting that body size-related traits respond almost independently to environmental heterogeneity. The effects of ecological factors analyzed in this study are discussed in order to elucidate the causal factors investigated （type of com- petition, crowding conditions and alternative host） affecting the election of the breeding site and/or the range of distribution of these cactophilic species.
文摘Aphids （Hemiptera： Aphididae） are phytophagous insects that are important agricultural pests. The enormous negative economic impacts caused by aphids worldwide are well known, and are mostly due to their high multiplication rate and the transmission of phytopathogenic viruses. Aphid management strategies mainly involve chemical treatments which are pollutants and are increasingly inefficient, since aphids have developed multiple insecticide-resistant mechanisms. Among the most economically important species is the green peach aptfid Myzus persicae Sulzer （Aphididae： Macrosiphini）, which is able to colonize a wide range of host plants belonging to many different families, and transmits numerous plant viruses. Because of its large prevalence, M. persicae has been the target of massive insecticide treatments; consequently, it has evolved several insecticide-resistant mechanisms. In this work, a collection of expressed genes from M. persicae is presented in order to identify putative genes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959 expressed sequence tags （EST） were annotated. Most sequences matched known genes corresponded to metabolism proteins （26%）, ribosomal proteins （ 23 % ） and structural proteins （8%）. Among them, several sequences corresponded to proteins putatively involved in sensing, degradation or detoxification of plant xenobiotic products.
