A General Coefficient of Similarity and Some of Its Properties

Gower, J. C.

doi:10.2307/2528823

Cited by 4,186 publications

(2,596 citation statements)

References 16 publications

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“…Only a small correlation was detected between these two distance estimates ( Table 3), showing that they probably assessed different portions of the genome. Dice (1945), estimated using 206 polymorphic bands; Dg morphological + molecular) , based on the complement of the genetic similarity index of Gower (1971); and Dg inbreeding , using the equation of Malécot (Ferreira & Zambalde, 1997). The cophenetic correlation coeffi cients were 0.70, 0.76, 0.75, and 0.90 for the four dendrograms, respectively.…”

Section: Resultsmentioning

confidence: 99%

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Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

Bertan

Carvalho

Oliveira

et al. 2009

Pesq. agropec. bras.

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-The objectives of this work were to estimate the genetic distance among wheat genotypes using morphological, pedigree, molecular, and combined morphological and molecular measures, to determine the correlations between these measures, and to evaluate the combining ability of the genotypes. Three generations and two planting designs were studied. Six wheat genotypes were crossed using a diallel design. The F 1 , F 2 and F 3 generations were evaluated in the fi eld, in the crop seasons of 2003, 2004 and 2005, under spaced plant and full-row planting designs. The estimated general and specifi c combining abilities of tested hybrids were infl uenced both by the generation and the planting design. The correlation coeffi cients among the distance measures and between these measures and genotype performances of different generations for the two planting designs were low to moderate. In order to obtain a more precise estimate of the genetic distance among cultivars and its association with the hybrid performance, more than one generation, planting design, and genetic distance estimation technique should be employed.Index terms: Triticum aestivum, combining ability, genetic variability, parental selection. Distâncias morfológicas, genealógicas e moleculares e suas associações com o desempenho de híbridos em trigoResumo -O objetivo deste trabalho foi estimar a distância genética entre genótipos de trigo, por meio de dados morfológicos, genealógicos, marcadores moleculares AFLP ("amplifi ed fragment length polymorphism"), usados individualmente ou simultaneamente, e calcular a correlação entre essas medidas de distância e a capacidade de combinação dos genótipos. Foram estudadas três gerações e dois sistemas de semeadura. Seis genótipos de trigo foram cruzados de forma dialélica. Os híbridos F 1 e as populações F 2 e F 3 foram avaliados em campo, nos anos agrícolas de 2003, 2004 e 2005, com os esquemas de semeadura de planta espaçada e em linha cheia. As capacidades gerais e específi cas de combinação dos híbridos testados foram infl uenciadas tanto pela geração quanto pelo esquema de semeadura. Os coefi cientes de correlação foram de baixo a moderado entre as medidas de distância e entre estas e o desempenho dos genótipos, nos dois esquemas de semeadura. Para a obtenção de uma estimativa fi el da distância genética entre cultivares e da sua associação com o desempenho dos híbridos, devem ser empregados mais de uma geração, sistema de semeadura e técnica de estimativa da distância genética.Termos para indexação: Triticum aestivum, capacidade de combinação, variabilidade genética, seleção de genitores.

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Section: Resultsmentioning

confidence: 99%

“…The analysis of genetic distance between parents assessed with combined morphological and molecular marker data was performed using the complement of Gower's similarity index (Gower, 1971), using the software MULTIV v. 2.3 (Pillar, 1997).…”

Section: Methodsmentioning

confidence: 99%

Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

Bertan

Carvalho

Oliveira

et al. 2009

Pesq. agropec. bras.

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“…The comparison among different flower‐type requirements can be tested through appropriate statistical methods for both normally and non‐normally distributed pollen grain counts, if necessary, with an eventual scale correction can be made using the ranging standardization (Gower, 1971; Hosmer & Lemeshow, 2000; Zar, 2010). …”

Section: Buzz Stressing and Quantitative Responsementioning

confidence: 99%

An affordable apparatus for fine‐controlled emulation of buzzing frequencies of bees for the testing hypothesis in buzz interactions

Rodrigues

Riguette

Pereira

et al. 2018

Ecology and Evolution

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The buzzing foraging behavior of female bees for pollen harvesting called the attention of early pollination biologists. Flower types that demand this buzzing behavior comprise about 20,000 species of different and phylogenetically unrelated plant taxa, suggesting that it had independently evolved many times among the flowering plants. Between the late 1970s and early 1980s, theoretical papers had modeled the energetics of buzz pollination, but, up to this moment, no hypothesis was experimentally tested concerning the theoretical basis of the energetics of buzz pollination. We present a cost‐effective and simple apparatus, including a digital and highly accurate frequency generator, and a device for the transference of buzz‐frequency energy to the receptive floral unity. The receptive floral unities may comprise the entire or partial androecium, or the tubular corolla, or, in some cases, the whole flower. This apparatus can be easily used in both laboratory and field conditions of research, as natural air currents are avoided, and the response of pollen liberation can be quantitatively measured by pollen grain counts that can be captured by adhesion in slide poured with an isosmotic lactate–glycerol media. The maximum displacement of the hardwire beam/claw system was 0.1170 ± 0.0006 mm @ 150 Hz; 0.021 ± 0.003 mm @ 250 Hz; 0.010 ± 0.001 mm @ 350 Hz; 0.0058 ± 0.0001 mm @ 450 Hz; and 0.0082 ± 0.0005 mm @ 550 Hz. Hypothesis contrasting frequency emission and pollen liberation measured as pollen grain counts may be tested in a species flower type by simple linear regression if pollen counts are normally distributed, or ordinal logistic regression, with non‐normal counts. The comparison among different flower‐type requirements can be tested through appropriate statistical methods for both normally and non‐normally distributed pollen grain counts.

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“…Variables that did not show any variation were also removed, as they provided little assistance to the development of the clusters (Köbrich et al, 2003). A similarity matrix was created between each variable included in the analysis, using simple matching and Euclidean methods for the discrete and quantitative variables respectively, as described by Gower (1971). The similarity coefficients calculated ranged from zero (completely different) to one (absolutely identical).…”

Section: Typology Analysismentioning

confidence: 99%

Characterisation of terminal sire sheep farm systems, based on a range of environmental factors: a case study in the context of genotype by environment interactions using Charollais lambs

McLaren

Lambe

Morgan-Davies

et al. 2014

Animal

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The objective of this study was to define different terminal sire flock environments, based on a range of environmental factors, and then investigate the presence of genotype by environment interactions (G × E) between the environments identified. Data from 79 different terminal sire flocks (40 Texel, 21 Charollais and 18 Suffolk), were analysed using principal coordinate and non-hierarchical cluster analyses, the results of which identified three distinct environmental cluster groups. The type of grazing, climatic conditions and the use of vitamins and mineral supplements were found to be the most important factors in the clustering of flocks. The presence of G × E was then investigated using data from the Charollais flocks only. Performance data were collected for 12 181 lambs, between 1990 and 2010, sired by 515 different sires. Fifty six of the sires had offspring in at least two of the three different cluster groups and pedigree information was available for a total of 161 431 animals. Traits studied were the 21-week old weight (21WT), ultrasound muscle depth (UMD) and log transformed backfat depth (LogUFD). Heritabilities estimated for each cluster, for each trait, ranged from 0.32 to 0.45. Genetic correlations estimated between Cluster 1 and Cluster 2 were all found to be significantly lower than unity, indicating the presence of G × E. They were 0.31 (±0.17), 0.68 (±0.14) and 0.18 (±0.21) for 21WT, UMD and LogUFD, respectively. Evidence of sires re-ranking across clusters was also observed. Providing a suitable strategy can be identified, there is potential for the optimisation of future breeding programmes, by taking into account the G × E observed. This would enable farmers to identify and select animals with an increased knowledge as to how they will perform in their specific farm environment thus reducing any unexpected differences in performance.

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A General Coefficient of Similarity and Some of Its Properties

Cited by 4,186 publications

References 16 publications

Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

Morphological, pedigree, and molecular distances and their association with hybrid wheat performance

An affordable apparatus for fine‐controlled emulation of buzzing frequencies of bees for the testing hypothesis in buzz interactions

Characterisation of terminal sire sheep farm systems, based on a range of environmental factors: a case study in the context of genotype by environment interactions using Charollais lambs

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