Caracterização citogenética e molecular em acessos de cana-de-açúcar (Saccharum spp.)
Carregando...
Data
2021-07-06
Autores
Ferreira, Glêyce de Oliveira
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A cana-de-açúcar é uma cultura amplamente cultivada em regiões tropicais e subtropicais, de grande importância econômica, principalmente, na produção de açúcar e etanol. O bagaço resultante da moagem da cana é uma importante fonte de energia renovável utilizada na produção de energia elétrica pelas indústrias canavieiras brasileiras com excedente comercializado para complementar a geração hídrica no país. A cana energia é uma cultivar rica em biomassa, obtida de cruzamentos com S. spontaneum, uma espécie selvagem com alta diversidade genética e adaptável com número variável de citótipos na faixa de 2n = 40 – 128. O Programa de Melhoramento Genético de Cana-de-Açúcar do Instituto Agronômico (IAC/APTA) possui Banco Ativo Germoplasma (BAG) de cana-de-açúcar composto por diversos acessos do Complexo Saccharum. O estudo visou à caracterização via marcadores moleculares do tipo microssatélites (SSR) de acessos do germoplasma básico de cana-de-açúcar e avaliação do número cromossômico de acessos de S. spontaneum. Doze pares de primers de SSR foram utilizados para estabelecer o perfil molecular e avaliar a estrutura populacional e a diversidade genética entre 64 acessos de cana-de-açúcar. Os dados obtidos foram avaliados por meio de metodologias baseadas em distâncias genéticas e modelos probabilísticos, índices de diversidade genética obtidos pelo programa POPGENE versão 1.32, além das estimativas de similaridade genética entre os acessos, a análise de estrutura populacional obtidas pelos programas Structure v.2.3.4 e Structure Harvester. Raízes com aproximadamente 1cm de comprimento foram coletadas para confecção de lâminas citológicas aplicando o método de coloração de Feulgen para contagem de cromossomos em metáfases e investigar a presença de citótipos de quatro acessos de S. spontaneum. Os dados obtidos da contagem dos cromossomos foram avaliados por meio dos parâmetros: média, moda, desvio padrão, coeficiente de variação e gráfico Boxplot usado para avaliar a dispersão da contagem do número de cromossomos dos acessos de S. spontaneum. Todos os marcadores foram considerados informativos de acordo com seu valor de PIC, a análise estrutural da população e de similaridade revelou a formação de dois grupos e a contagem de cromossomos revelou a presença de três citótipos. Os resultados obtidos contribuirão para o manejo, conservação e utilização do germoplasma em programas de melhoramento genético de cana-de-açúcar para o desenvolvimento de cultivares melhoradas que atendam à necessidade do produtor e do consumidor, a exemplo da cana energia.
Sugarcane crop is widely grown in tropical and subtropical regions, and has a great economic importance, mainly in sugar and ethanol production. The bagasse resulting from the sugarcane crushing is an important source of renewable energy used in the production of electric energy by the Brazilian sugarcane industries with surplus commercialized to complement the hydro generation in the country. Energy cane is a cultivar rich in biomass, obtained from crosses with S. spontaneum, a highly diverse and adaptable wild species with a variable number of cytotypes ranging from 2n = 40 – 128. The Sugarcane Genetic Breeding Program of the Agronomic Institute (IAC/APTA) has an Active Germplasm Bank (BAG) of sugarcane composed of several accessions of the Saccharum Complex. The study aimed the characterization of basic sugarcane germplasm accessions via microsatellite molecular markers (SSR) and the evaluation of the chromosome number of S. spontaneum accessions. Twelve SSR primer pairs were used to establish the molecular profile, genetic diversity and population structure among 64 sugarcane accessions. The data were evaluated using methodologies based on genetic distances and probabilistic models, genetic diversity indexes obtained by using the POPGENE version 1.32 software in addition to the genetic similarity estimates between accessions, analysis of population structure obtained by the Structure v.2.3.4 and Structure Harvester software. Roots of approximately 1cm length were collected for cytological slides confection using the Feulgen staining method for chromosome counting in metaphase and cytotype definition of four S. spontaneum accessions. The data from the chromosome count was evaluated using the parameters: mean, mode, standard deviation, coefficient of variation and Boxplot graphics applied to evaluate the dispersion of the chromosome number couting of S. spontaneum accessions. All markers were considered informative according to their PIC value, the population structure analysis and similarity revealed the formation of two groups and the chromosome count the presence of three cytotypes. The results will contribute to the management, conservation and use of germplasm in sugarcane genetic breeding programs for the development of improved cultivars that meet the needs of producers and consumers, such as energy cane.
Sugarcane crop is widely grown in tropical and subtropical regions, and has a great economic importance, mainly in sugar and ethanol production. The bagasse resulting from the sugarcane crushing is an important source of renewable energy used in the production of electric energy by the Brazilian sugarcane industries with surplus commercialized to complement the hydro generation in the country. Energy cane is a cultivar rich in biomass, obtained from crosses with S. spontaneum, a highly diverse and adaptable wild species with a variable number of cytotypes ranging from 2n = 40 – 128. The Sugarcane Genetic Breeding Program of the Agronomic Institute (IAC/APTA) has an Active Germplasm Bank (BAG) of sugarcane composed of several accessions of the Saccharum Complex. The study aimed the characterization of basic sugarcane germplasm accessions via microsatellite molecular markers (SSR) and the evaluation of the chromosome number of S. spontaneum accessions. Twelve SSR primer pairs were used to establish the molecular profile, genetic diversity and population structure among 64 sugarcane accessions. The data were evaluated using methodologies based on genetic distances and probabilistic models, genetic diversity indexes obtained by using the POPGENE version 1.32 software in addition to the genetic similarity estimates between accessions, analysis of population structure obtained by the Structure v.2.3.4 and Structure Harvester software. Roots of approximately 1cm length were collected for cytological slides confection using the Feulgen staining method for chromosome counting in metaphase and cytotype definition of four S. spontaneum accessions. The data from the chromosome count was evaluated using the parameters: mean, mode, standard deviation, coefficient of variation and Boxplot graphics applied to evaluate the dispersion of the chromosome number couting of S. spontaneum accessions. All markers were considered informative according to their PIC value, the population structure analysis and similarity revealed the formation of two groups and the chromosome count the presence of three cytotypes. The results will contribute to the management, conservation and use of germplasm in sugarcane genetic breeding programs for the development of improved cultivars that meet the needs of producers and consumers, such as energy cane.
Descrição
Palavras-chave
Diversidade genética, Cromossomos, Saccharum officinarum, Cromossomos