Variabilidade genética em progênies de polinização aberta de Eucalyptus urophylla
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Data
2013-11-18
Autores
Moraes, Cristiano Bueno de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Os danos provocados pelas geadas severas em plantios de reflorestamentos de eucaliptos trazem prejuízos consideráveis para o setor florestal e agronegócio brasileiro. Essas perdas podem variar dependendo da intensidade da geada e da tolerância da espécie ao fenômeno. Na região sul do Brasil, à ocorrência de geadas é o principal fator que limita a produção de madeira do gênero eucaliptos, devido à inibição ou alterações de vários processos importantes no crescimento e desenvolvimento das plantas no período de inverno. Desta maneira, o objetivo da pesquisa foi estudar a variabilidade genética em progênies de polinização aberta de Eucalyptus urophylla para tolerância à geada em diferentes ambientes. Foram instalados três testes de progênies com material genético de Eucalyptus urophylla, todos em delineamento em blocos casualizados. Os testes foram implantados em áreas com histórico de observação de ocorrência de geada pertencentes às empresas Eucatex no município de Itatinga/SP e na Palmasola no município de Palma Sola/SC. O teste testemunha foi instalado na Estação Experimental de Anhembi/SP onde as geadas são raras. Os testes de progênies foram avaliados com: 150 progênies, quatro repetições, seis plantas por parcela, totalizando 3.600 plantas para cada um dos três experimentos. Foram realizadas as seguintes avaliações: a) medições de altura de plantas; b) diâmetro à altura do peito das plantas; c) volume de madeira; d) percentagem de bifurcação; e) sobrevivência de plantas e f) danos por geada. Os parâmetros genéticos foram estimados com base no procedimento REML/BLUP. Os resultados apontaram que à ocorrência de geada na região de Palma Sola/SC promoveram 36% de plantas bifurcadas e 22% de mortalidade, diferentemente das regiões de Itatinga/SP e Anhembi/SP. Foi verificada interação genótipos x ambientes para as progênies nas três regiões...
The damages caused by severe frosts on eucalypt plantings bring outstanding losses for Brazilian forest sector and agribusiness. Such losses may vary according to the frost intensity and the species tolerance. In the Southern Brazil, the occurrence of frosts is one of the main factor limiting the eucalypts wood production, due to inhibition or changes in several important processes to the plants growth and its development during the winter. Therefore, the objective of this research was to study the genetic variability of open-pollinated progenies of Eucalyptus urophylla for frost tolerance in different environments. We set up three progenies trials of Eucalyptus urophylla using the statistical design of randomized blocks. The trials were set up on areas with historic of frost occurrence belonging to Eucatex company in Itatinga municipality/SP and in Palmasola company in Palma Sola municipality/SC, both in Brazil. The control trial was set up in Anhembi Experimental Station in Anhembi/SP-Brazil with rare occurrence of frosts. The progenies trials were with 150 progenies, four replications, six plants per plot, totalizing 3.600 plants per trial. The following evaluations were performed with measurements of: a) plants height; b) diameter of breast height; c) wood volume; d) percentage of bifurcation, e) plants survival, and f) frost damage. The quantitative genetic parameters were estimated by REML/BLUP. The results showed that the occurrence of frosts in Palma Sola/SC promoted 36% of forked plants and 22% of mortality, different from Itatinga/SP and Anhembi/SP. There were genotype x environment interactions for progenies in those three climate regions. The methodology of MHVG (stability), PRVG (adaptability), and MHPRVG (productivity, stability and adaptability) was efficient for selection of productivity and frost-tolerant genotypes for Itatinga/SP and Palma Sola/SC regions, Brazil ...
The damages caused by severe frosts on eucalypt plantings bring outstanding losses for Brazilian forest sector and agribusiness. Such losses may vary according to the frost intensity and the species tolerance. In the Southern Brazil, the occurrence of frosts is one of the main factor limiting the eucalypts wood production, due to inhibition or changes in several important processes to the plants growth and its development during the winter. Therefore, the objective of this research was to study the genetic variability of open-pollinated progenies of Eucalyptus urophylla for frost tolerance in different environments. We set up three progenies trials of Eucalyptus urophylla using the statistical design of randomized blocks. The trials were set up on areas with historic of frost occurrence belonging to Eucatex company in Itatinga municipality/SP and in Palmasola company in Palma Sola municipality/SC, both in Brazil. The control trial was set up in Anhembi Experimental Station in Anhembi/SP-Brazil with rare occurrence of frosts. The progenies trials were with 150 progenies, four replications, six plants per plot, totalizing 3.600 plants per trial. The following evaluations were performed with measurements of: a) plants height; b) diameter of breast height; c) wood volume; d) percentage of bifurcation, e) plants survival, and f) frost damage. The quantitative genetic parameters were estimated by REML/BLUP. The results showed that the occurrence of frosts in Palma Sola/SC promoted 36% of forked plants and 22% of mortality, different from Itatinga/SP and Anhembi/SP. There were genotype x environment interactions for progenies in those three climate regions. The methodology of MHVG (stability), PRVG (adaptability), and MHPRVG (productivity, stability and adaptability) was efficient for selection of productivity and frost-tolerant genotypes for Itatinga/SP and Palma Sola/SC regions, Brazil ...
Descrição
Palavras-chave
Melhoramento genetico, Geada, Eucalipto - Aspectos genéticos, Florestas - Medição, Breeding
Como citar
MORAES, Cristiano Bueno de. Variabilidade genética em progênies de polinização aberta de Eucalyptus urophylla. 2013. xvii, 90 f. Tese (doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agronômicas de Botucatu, 2013.