Estratégias de amostragem e estabelecimento de coleções nucleares

Vasconcelos, Edmar Soares de; Cruz, Cosme Damião; Bhering, Leonardo Lopes; Ferreira, Adésio

doi:10.1590/s0100-204x2007000400008

Cited by 9 publications

(5 citation statements)

References 9 publications

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“…Os acessos dos bancos de germoplasma foram descritos em relação a 21 características morfoagronômicas (Tabela 1), tendo-se tomado por base os dados do estudo de Huaman et al (1999) Vasconcelos et al (2007a), pelo método de agrupamento de Tocher com aglomeração inversa. As coleções nucleares, obtidas para as coleções de 100 e 250 acessos, foram formadas por amostragem de 10%, ou seja, 10 e 25 entradas respectivamente.…”

Section: Methodsunclassified

“…Há, ainda, um método que não faz uso de agrupamento seguido de amostragem -o método de agrupamento de Tocher com critério de aglomeração inverso (Vasconcelos et al, 2007a) -que consiste em formar um único grupo, pela seleção dos acessos que permitem obtenção da maior divergência dentro da coleção original e que passariam a constituir a coleção nuclear.…”

Section: Introductionunclassified

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Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

Vasconcelos

Cruz

Silva³

et al. 2010

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi verificar o efeito do tamanho da coleção original de germoplasma sobre eficácia de diferentes métodos de agrupamento e de amostragem, utilizados na obtenção de coleções nucleares, e comparar esses métodos no estabelecimento de coleções nucleares. Foram simulados sete tamanhos de coleções originais e utilizadas sete estratégias de amostragem para estabelecimento de coleções nucleares, com uso de caracteres morfo-agronômicos. Oito estratégias de obtenção de coleção nuclear foram empregadas, seis com técnicas de agrupamento (Tocher e Tocher sequencial) e duas sem agrupamento (aleatória e Tocher invertido). Nas estratégias de agrupamento, foram empregadas as amostragens constante, logarítmica e proporcional. Determinaram-se a variância explicada, o valor do coeficiente de determinação, o coeficiente de coincidência e o coeficiente de coincidência do desvio-padrão entre a coleção nuclear e a coleção original. As estratégias de amostragem constante e logarítmica geram coleções nucleares representativas da coleção original. O agrupamento de Tocher sequencial é mais eficaz na representação da coleção original pela coleção nuclear do que o agrupamento de Tocher. Entre as estratégias avaliadas, a amostragem pelo método de Tocher com critério de aglomeração inverso foi a mais eficiente na geração de coleções nucleares representativas das coleções originais.Termos para indexação: agrupamento de acessos, estratégias de amostragem, método de Tocher inverso, recursos genéticos. Size of original collection, grouping and sampling methods for the obtention of germplasm core collectionAbstract -The objective of this study was to verify the effect of original germplasm collection size on the effectiveness of different clustering methods and sampling, used to obtain core collections, and to compare these methods in the establishment of core collections. Simulations were made for seven sizes of original collections, and seven sampling strategies were used for the establishment of core collections using morpho-agronomic traits. Eight strategies for obtaining core collections were used, six of them by grouping techniques (Tocher and sequential Tocher), and two without grouping (random and Tocher with inverted criteria grouping). For grouping strategies, constant, logarithmic and proportional sampling were used. The explained variance, the value of the determination coefficient, the coincidence coefficient, and the coincidence standard deviation coefficient between the core and the original collections were determined. The constant and logarithmic sampling strategies generate core collections which are representative of the original collections. The sequential Tocher grouping is more efficient in representing the original collection by the core collection than the Tocher's. Among the evaluated strategies the sampling by Tocher's inversed grouping criterion is the most efficient to generate representative core collections of the original collections.

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Section: Methodsunclassified

Section: Introductionunclassified

Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

Vasconcelos

Cruz

Silva³

et al. 2010

Pesq. agropec. bras.

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“…All are based on the information available from the accesses, such as passport data and morphological data. Several strategies have been developed for the development and formation of nuclear collections as mentioned by Shoen & Brown [15], Balfourier et al [16], Hintum et al [17], Hu et al [18], Wang et al [19], Vasconcelos et al [20], Cordeiro & Abadie [21]. The considerable number of accessions in ex situ collections shows the wide genetic diversity of the species involved in this project.…”

Section: Introductionmentioning

confidence: 99%

Experimental Statistical for Genetic Breeding Study of Wheat Crop

Batista Ferreira

2023

Arch Agri Res Technol

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The key purpose of this study was used experimental statistics methods to evaluate, characterize and conserve the genetic resources of the Active Wheat Germplasm Bank (AWGB) and promote pre-breeding the Rural Development of Paraná State (IDR Paraná), Brazil. For that purpose, 209 accessions from the IDR Paraná Active Germplasm Bank and 16 cultivars in a simple lattice design (15x15) were sown in the experimental area of IDR Paraná, in Londrina, Paraná State, and data from 16 morphological and agronomic characteristics were taken. The statistics methods used were the analysis of variance (ANOVA), grouping of averages, analysis of simple linear correlation and analysis of genetic diversity with subsequent grouping by the UPGMA and Tocher methods were performed. It was verified the average efficiency of the lattice was 1.21 % with IC5 %: [99.31 ~ 103.11 %], representing little efficiency in relation to the randomized block design. Fourteen variables showed significance by the F test, indicating that at least one genotype differs from the others for each variable. By the analysis of genetic diversity, 3 groups were obtained in which the genotypes T092125 (Group C) and IA 072118 with T062113 (Group B) were in two isolated groups and the third group gathering the remaining 223 genotypes. This fact does not directly represent a narrow genetic basis for Active Germplasm Bank of IDR Paraná, due than 99 % of the variation is actually contained in agronomic variables: days to maturation (MAT) and ear (ESP), plant height (AP) and ear size (TE). Taking as a basis the grouping of means by Scott-Knott for these variables and grain weight per ear (PG / ESP), the formation of 4 for AP and ESP, 3 TE and PG / ESP groups, 2 for DC and P100G, reflecting wide diversity within each variable and in the set of these variables. The correlation analyzes showed a positive value between TE with PG / ESP and DC and a negative value between ESP and PG / ESP, both significant. Thus, the direction of crossings, to increase productivity, between genotypes of this set, must be in the direction of obtaining plants with earlier earing and with larger ears size. It can be inferred that the set of accessions evaluated has a broad genetic basis for agronomic variables. The 225 characterized accessions represent 49 % of the total accessions of wheat in the Active Wheat Germplasm Bank (AWGB) that have been regenerated and multiplied, being able to be directed to crossings focusing on pre-improvement and / or improvement to obtain new cultivars.

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“…Thus, there is greater facility in effectively using the genetic resources (NAYAK et al, 2014;MARCHINI, 2019), and that encourages researchers to more frequently draw on the stored germplasm. Consequently, various authors have presented strategies and sampling methods in selection of accessions to obtain a core collection (CHANDRA et al, 2002;LI et al, 2004;ZEWDIE et al, 2004;ABADIE et al, 2005;VASCONCELOS et al, 2007;VASCONCELOS et al, 2010). These principles and methodologies concerning the ideal size and the appropriate choice of individuals are still controversial.…”

Section: Introductionmentioning

confidence: 99%

“…Such a method consists of three steps: (1) the accessions may be allocated in each group (stratum) taking origin, passport data, and phenotypic, genotypic, or ecogeographic data into consideration; (2) the number of accessions is allocated in each group using the direct or logarithmic proportion or combinations between the direct proportion and an index (e.g., direct proportion plus the Shannon index); and (3) the individuals of each group are chosen at random or through genetic information among accessions (FRANCO et al, 2005;SILVA, 2016). In addition, several methods and software programs have been cited in the literature that can assist in the formation of a core collection (GOUESNARD et al, 2001;FRANCO et al, 2006;VASCONCELOS et al, 2007;KIM et al, 2007;POLICRITI;SGARRO, 2011).…”

Section: Introductionmentioning

confidence: 99%

Core collection of common bean formed from traditional Brazilian germplasm

et al. 2022

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The aim of this study was to select traditional accessions, compose a core collection of common bean, and assess the representativeness of the collection in relation to the base collection accommodated in the BAG of Embrapa using analysis strategies for multivariate models. We used data characterizing 2903 accessions from collections representing all geographic areas of Brazil regarding three morphologic descriptors (seed color, growth habit type, and seed size) and four ecogeographic descriptors (geographical areas, states, altitudes, and soil classes). A set of 400 accessions were selected using multivariate models applied to the data transformed in multibinary values. The accessions sampled had maximum similarity (100%) to the traditional collection, phenotypic diversity, and representative heterogeneity in relation to the traditional collection. In the core collection, the accessions represented 9.5% of the traditional accessions and were equivalent to 3% of the accessions of the base collection. Thus, it is possible to form a core collection that is representative of the base collection regarding genetic diversity and the conservation of rare alleles.

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Estratégias de amostragem e estabelecimento de coleções nucleares

Cited by 9 publications

References 9 publications

Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

Experimental Statistical for Genetic Breeding Study of Wheat Crop

Core collection of common bean formed from traditional Brazilian germplasm

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