棉属不同种的分类,早年是以形态特征进行划分的,近代则以细胞学、地理生态分布及其可交配程度三者相结合为依据。同工酶技术的发展,迅速被利用在研究植物不同种属间亲缘关系及起源上。B.L.Johnson and M.M.Thein(1970)用蛋白质电泳法对...棉属不同种的分类,早年是以形态特征进行划分的,近代则以细胞学、地理生态分布及其可交配程度三者相结合为依据。同工酶技术的发展,迅速被利用在研究植物不同种属间亲缘关系及起源上。B.L.Johnson and M.M.Thein(1970)用蛋白质电泳法对棉花系统发育中的亲缘关系进行过研究,从而补充了棉属进化的理论;吴小月(1983)曾对四个栽培棉种的酯酶和过氧化物同工酶作过分析;孙传渭等(1989)和钱思颖(1985)系统分析比较了棉属不同种及品种的种子酯酶同工酶。1987年,我们开展了种子酯酶同工酶的分析工作,其目的想从酶的角度探讨棉属种的关系。展开更多
A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified frag...A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified fragment length polymorphism （AFLP） and simple sequence repeat （SSR） markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ＇Monagha＇ and ＇Sefied＇ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.展开更多
Clarias ganepinus from wild population, which was purchased from fish mongers in Ado-Ekiti, Nigeria, were examined for possible deformities in their body. Eighty individuals were collected. Various types of deformitie...Clarias ganepinus from wild population, which was purchased from fish mongers in Ado-Ekiti, Nigeria, were examined for possible deformities in their body. Eighty individuals were collected. Various types of deformities observed were recorded and later photographed. The present study reported for the first time the occurrence of morphological deformities in C. gariepinus natural ecosystem in Ado-Ekiti, Nigeria. The rivers, where the fish were collected, were found to have been exposed to persistent human activities. The possible causes of the deformities may be pollution from human activities or other factors such as poor nutrition, heredity, diseases. The etiology of the deformities in Clarias under this condition is recommended to be studied in detail.展开更多
Human proximity often have negative consequences for wildlife. However, animals may also benefit from human proximity in terms of availability of resources and protection against predators and parasites. We recorded t...Human proximity often have negative consequences for wildlife. However, animals may also benefit from human proximity in terms of availability of resources and protection against predators and parasites. We recorded the distance between all birds detected during the breeding season along 18 5-kin transects and the nearest inhabited house in three areas of 50 km2 in Spain, France, and Denmark. More than three quarters of birds were located closer than 100 m to the nearest house, while the null expectation was less than a third. Mean distance for species was correlated with degree of bird urbanization and with flight initiation distance. Habitat specialist species with small breeding territories tended to live closer to houses. Birds from species having more broods per year, larger annual fecundity and lower nest predation rate lived closer to human habitation. Breeding range size, population density, and continental breeding population sizes were larger for species living closer to human habitation. Most relationships between distance to houses and bird traits had a strong phylogenetic signal, but most additive trait effects remained after phylogenetic correction. Proximity to human habitation was a main driver of the distribution of birds, with most individuals and species tightly linked to inhabited houses. Living close to human habitation was associated with success in the colonization of urban habitats and with consistent changes in distribution, abundance, behavior, and life history. Replicated measurements of the spatial and tempo- ral variation in these distributions may be useful for monitoring and analyzing the ongoing process of organisms＇ urbanization.展开更多
文摘棉属不同种的分类,早年是以形态特征进行划分的,近代则以细胞学、地理生态分布及其可交配程度三者相结合为依据。同工酶技术的发展,迅速被利用在研究植物不同种属间亲缘关系及起源上。B.L.Johnson and M.M.Thein(1970)用蛋白质电泳法对棉花系统发育中的亲缘关系进行过研究,从而补充了棉属进化的理论;吴小月(1983)曾对四个栽培棉种的酯酶和过氧化物同工酶作过分析;孙传渭等(1989)和钱思颖(1985)系统分析比较了棉属不同种及品种的种子酯酶同工酶。1987年,我们开展了种子酯酶同工酶的分析工作,其目的想从酶的角度探讨棉属种的关系。
文摘A total 23 morphological traits, 19 AFLP-primer combinations, 80 RAPD primers and 32 SSR primer pair were used to compare the informativeness and efficiency of random amplified polymorphic DNA （RAPD）, amplified fragment length polymorphism （AFLP） and simple sequence repeat （SSR） markers in establishing genetic relationships among 29 almond cultivars and three related wild species. SSRs presented a high level of polymorphism and greater information content, as assessed by the expected hetrozygosity, compared to AFLPs and RAPDs. The lowest values of expected hetrozygosity were obtained for AFLPs; however AFLPs showed the highest efficiency, owing to their capacity to reveal large numbers of bands per reaction, which led to high values for various types of indices of diversity. All the three techniques discriminated almond genotypes very effectively, except that SSRs failed to discriminate between ＇Monagha＇ and ＇Sefied＇ almond genotypes. The correlation coefficients of similarity were statistically significant for all the three marker systems, but were lower for the SSR data than for RAPDs and AFLPs. For all the markers, high similarity in dendrogram topologies was obtained, although some differences were observed. All the dendrograms, including that obtained by the combined use of all the marker data, reflect relationships for most of cultivars according to their geographic diffusion. AMOVA detected more variation among cultivated and related wild species of almond within each geographic group. Bootstrap analysis revealed that the number of markers used was sufficient for reliable estimation of genetic similarity and for meaningful comparisons of marker types.
文摘Clarias ganepinus from wild population, which was purchased from fish mongers in Ado-Ekiti, Nigeria, were examined for possible deformities in their body. Eighty individuals were collected. Various types of deformities observed were recorded and later photographed. The present study reported for the first time the occurrence of morphological deformities in C. gariepinus natural ecosystem in Ado-Ekiti, Nigeria. The rivers, where the fish were collected, were found to have been exposed to persistent human activities. The possible causes of the deformities may be pollution from human activities or other factors such as poor nutrition, heredity, diseases. The etiology of the deformities in Clarias under this condition is recommended to be studied in detail.
文摘Human proximity often have negative consequences for wildlife. However, animals may also benefit from human proximity in terms of availability of resources and protection against predators and parasites. We recorded the distance between all birds detected during the breeding season along 18 5-kin transects and the nearest inhabited house in three areas of 50 km2 in Spain, France, and Denmark. More than three quarters of birds were located closer than 100 m to the nearest house, while the null expectation was less than a third. Mean distance for species was correlated with degree of bird urbanization and with flight initiation distance. Habitat specialist species with small breeding territories tended to live closer to houses. Birds from species having more broods per year, larger annual fecundity and lower nest predation rate lived closer to human habitation. Breeding range size, population density, and continental breeding population sizes were larger for species living closer to human habitation. Most relationships between distance to houses and bird traits had a strong phylogenetic signal, but most additive trait effects remained after phylogenetic correction. Proximity to human habitation was a main driver of the distribution of birds, with most individuals and species tightly linked to inhabited houses. Living close to human habitation was associated with success in the colonization of urban habitats and with consistent changes in distribution, abundance, behavior, and life history. Replicated measurements of the spatial and tempo- ral variation in these distributions may be useful for monitoring and analyzing the ongoing process of organisms＇ urbanization.
