Invasive species are often characterised by the introduction of low numbers of individuals and a small genetic pool which could give rise to a population with a lower genetic diversity than the original population. Pe...Invasive species are often characterised by the introduction of low numbers of individuals and a small genetic pool which could give rise to a population with a lower genetic diversity than the original population. Perna viridis was first reported on the west coast of Trinidadin1990 inthe Point Lisas Industrial estate. They may have been first introduced either as juvenile free floating mussels (spat) or as adults attached to the hulls of ships. This gregarious species spread rapidly throughout the Caribbean toVenezuela,KingstonHarbor(Jamaica) and by 1999 was reported inTampaBay(Florida). Genetic analysis was done on tissue samples fromTrinidadto determine the genetic similarity of newly collected specimens (2009) with archived specimens (collected 1994). Results suggest that there may not be any genetic variation in the population of Perna viridis, even approximately 20 years after initial colonization. These results suggest that there was no evidence of genetic bottlenecks in the population of P. viridis fromTrinidad.展开更多
[ Objective] The paper was to optimize the optimal conditions for seed germination and seedling emergence of green foxtail [ Setar/a viridis （ L. ） Beauv. ], so as to solve the problem of serious damage caused by gr...[ Objective] The paper was to optimize the optimal conditions for seed germination and seedling emergence of green foxtail [ Setar/a viridis （ L. ） Beauv. ], so as to solve the problem of serious damage caused by green foxtail. [Method] Using the orthogenal test and the LSD method of software SPSS 18.0, with the number of emerged seedlings of green foxtail as the evaluation index, the influencing factors such as pretreatment of green foxtail, earth covering depth, soil temperature and soil moisture content were compared in the test. [Result] These four experimental factors had great impact on seed germination characteristics of green foxtail. The optimal scheme for seedling emergence of green foxtail was as follows： pretreatment of green foxtail for 3 d, earth covering depth 0.5 cm, soil temperature 32 ℃, soil moisture content 15%. The optimum condition was consistent with the actual situation of serious damage of green foxtail （ suffering moderate and heavy rainfall after sowing and before seedling of millet ）. Avoiding sowing millet before moderate and heavy rainfall could effectively control serious damage of green fox＇tail. [ Conclusion] The study provided theoretical support for effective control against the vicious weed green foxtail.展开更多
文摘Invasive species are often characterised by the introduction of low numbers of individuals and a small genetic pool which could give rise to a population with a lower genetic diversity than the original population. Perna viridis was first reported on the west coast of Trinidadin1990 inthe Point Lisas Industrial estate. They may have been first introduced either as juvenile free floating mussels (spat) or as adults attached to the hulls of ships. This gregarious species spread rapidly throughout the Caribbean toVenezuela,KingstonHarbor(Jamaica) and by 1999 was reported inTampaBay(Florida). Genetic analysis was done on tissue samples fromTrinidadto determine the genetic similarity of newly collected specimens (2009) with archived specimens (collected 1994). Results suggest that there may not be any genetic variation in the population of Perna viridis, even approximately 20 years after initial colonization. These results suggest that there was no evidence of genetic bottlenecks in the population of P. viridis fromTrinidad.
基金Supported by Science and Technology Support Program of Hebei Province(09250307D)Special Fund for Agro-scientific Research in the Public Interest(20120304201)
文摘[ Objective] The paper was to optimize the optimal conditions for seed germination and seedling emergence of green foxtail [ Setar/a viridis （ L. ） Beauv. ], so as to solve the problem of serious damage caused by green foxtail. [Method] Using the orthogenal test and the LSD method of software SPSS 18.0, with the number of emerged seedlings of green foxtail as the evaluation index, the influencing factors such as pretreatment of green foxtail, earth covering depth, soil temperature and soil moisture content were compared in the test. [Result] These four experimental factors had great impact on seed germination characteristics of green foxtail. The optimal scheme for seedling emergence of green foxtail was as follows： pretreatment of green foxtail for 3 d, earth covering depth 0.5 cm, soil temperature 32 ℃, soil moisture content 15%. The optimum condition was consistent with the actual situation of serious damage of green foxtail （ suffering moderate and heavy rainfall after sowing and before seedling of millet ）. Avoiding sowing millet before moderate and heavy rainfall could effectively control serious damage of green fox＇tail. [ Conclusion] The study provided theoretical support for effective control against the vicious weed green foxtail.
