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Previous attempts to resolve the Ceratitis FAR complex (Ceratitis
fasciventris, Ceratitis
anonae, Ceratitis
rosa, Diptera, Tephritidae) showed contrasting results and revealed the occurrence of five microsatellite genotypic clusters (A, F1, F2, R1, R2). In this paper we explore the potential of wing morphometrics for the diagnosis of FAR morphospecies and genotypic clusters. We considered a set of 227 specimens previously morphologically identified and genotyped at 16 microsatellite loci. Seventeen wing landmarks and 6 wing band areas were used for morphometric analyses. Permutational multivariate analysis of variance detected significant differences both across morphospecies and genotypic clusters (for both males and females). Unconstrained and constrained ordinations did not properly resolve groups corresponding to morphospecies or genotypic clusters. However, posterior group membership probabilities (PGMPs) of the Discriminant Analysis of Principal Components (DAPC) allowed the consistent identification of a relevant proportion of specimens (but with performances differing across morphospecies and genotypic clusters). This study suggests that wing morphometrics and PGMPs might represent a possible tool for the diagnosis of species within the FAR complex. Here, we propose a tentative diagnostic method and provide a first reference library of morphometric measures that might be used for the identification of additional and unidentified FAR specimens. 相似文献
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模糊C-均值聚类和TWINSPAN分类的比较研究 总被引:4,自引:0,他引:4
以英国威尔士北部Snowdonia山地Aber山谷植被为例,对模糊c-均值聚类和TWINSPAN分类进行了应用和比较研究。两种方法的结果一致。模糊c-均值聚类结果给出样地和植被类型间的隶属程度,在一定程度上优于TWINSPAN。 相似文献
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Genomic copy number variations (CNVs) are considered as a significant source of genetic diversity and widely involved in gene expression and regulatory mechanism, genetic disorders and disease risk, susceptibility to certain diseases and conditions, and resistance to medical drugs. Many studies have targeted the identification, profiling, analysis, and associations of genetic CNVs. We propose herein two new fuzzy methods, taht is, one based on the fuzzy inference from the pre-processed input, and another based on fuzzy C-means clustering. Our solutions present a higher true positive rate and a lower false negative with no false positive, efficient performance and consumption of least resources. 相似文献
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模糊C-均值聚类和TWINSPAN分类的比较研究 总被引:4,自引:0,他引:4
以英国威尔士北部Snowdonia山地Aber山谷植被为例,对模糊c-均值聚类和TWINSPAN分类进行了应用和比较研究。两种方法的结果一致。模糊c-均值聚类结构给出样地和植被类型间的隶属程度,在一定程度上优于TWINSPAN。 相似文献
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以采自河北、乌审旗、榆阳、神木、固阳5个地区的一年生长柄扁桃(Amygdalus pedunculata Pall.)实生苗为试材,研究其叶片在水分胁迫下的解剖结构与生理生化特性,来确定其抗旱性强弱。结果表明:(1)水分胁迫后各地区长柄扁桃的叶片解剖结构存在显著性差异,并由隶属函数法对解剖结构综合分析得出这5个地区长柄扁桃的抗旱性顺序为:榆阳〉神木〉固阳〉乌审旗〉河北。(2)随着干旱时间的延长,各地区长柄扁桃的叶片相对含水量、质膜透性、丙二醛含量均呈上升趋势,且抗旱性弱的值越大,变化幅度也较大;SOD和POD活性、游离脯氨酸和可溶性蛋白含量均随胁迫的加强呈先升高后降低或直接降低的趋势,且抗旱性越强活性值或含量越高。(3)在干旱胁迫下Chl a和Chl b都呈先升高后降低的趋势,但Chl b对水分胁迫的反应较Chl a敏感;Car则呈下降趋势,其中榆阳和神木地区的长柄扁桃在胁迫40 d后光合色素含量均为最高。研究发现:长柄扁桃通过调整自身的叶片结构和各项生理生化特性来减缓水分胁迫带来的伤害,并由各项指标综合分析得出5个地区长柄扁桃的抗旱性顺序为:榆阳〉神木〉固阳〉乌审旗〉河北,为进一步的品种选育奠定了基础,并为长柄扁桃的产业化开发提供了理论依据。 相似文献
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Mercury pollution in fields has become a potential threat to human health. Planting wheat cultivars with low mercury accumulation in slight or medium mercury-polluted fields is an efficient solution to ensure food safety. Therefore, this study evaluated the mercury resistance and accumulation characteristics of 30 generalized wheat cultivars in major wheat-producing areas of China. A modified membership function that considers the weight of each trait was used.Results demonstrated that the plant height of wheat significantly increased under both low mercury and high mercury stresses. The uppermost internode length significantly increased while the spikelet number significantly decreased under low mercury stress. Yield-related traits, including total grain number, fresh grain yield, and dry grain yield, significantly decreased under high mercury stress. The mercury concentrations in wheat grains presented a significant negative correlation with the mercury resistance coefficients of plant height (−0.38*), spike length (−0.39*), and fresh grain yield (−0.38*) under high mercury stress. The heritability of all traits reached medium to high levels, ranging from 0.31 to 0.68. This finding suggested that the investigated traits are stable and suitable for the assessment system. Selection criteria for wheat mercury resistance were established using discriminant analysis, which integrated the mercury resistance coefficients of effective tiller number, fresh grain yield, and dry biomass into the discriminant function under low mercury stress and the mercury resistance coefficients of dry grain yield and dry biomass under high mercury stress. Ultimately, Liangxing-99, Nongda-3163, and Gaocheng-8901 were screened for high mercury resistance and low mercury accumulation. These wheat cultivars could be planted in fields with low or medium mercury pollution to obtain safe grains. 相似文献
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