Brazilian Archives of Biology and Technology
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12090
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Item Genetic variability for frost resistance among coffea accessions assessed in the field and in a cold chamber(Instituto de Tecnologia do Paraná - Tecpar, 2005-01) Petek, Marcos Rafael; Sera, Tumoru; Alteia, Marcos ZorzenonThe genetic variability for frost resistance was evaluated in field conditions and cold chamber among Coffea accessions. Results showed that C. liberica var. dewevrei and C. racemosa, as well as hybrids obtained from these species were more resistant to frost. There was a great genetic variability for frost resistance among the evaluated sources (b 2 = 0,98). The correlation estimated between damages in the field and in the cold chamber was 0.933**, therefore, this methodology was efficient and feasible and could be potentially used in a breeding program.Item Resistance to leaf rust in coffee carrying SH3 gene and others SH genes(Instituto de Tecnologia do Paraná - Tecpar, 2007-09) Sera, Gustavo Hiroshi; Sera, Tumoru; Ito, Dhalton Shiguer; Azevedo, José Alves de; Mata, João Siqueira da; Dói, Deisy Saori; Ribeiro Filho, Claudionor; Kanayama, Fabio SeidiThe aim of this work was to evaluate the resistance to rust in coffee carrying SH3 gene and other SH genes. Twenty one CIFC’s coffee trees with several resistance genes SH were evaluated in field conditions. All the evaluated coffees carrying SH3 gene presented resistance to the rust. It was possible that rust races with the virulence gene v3 in the Paraná State didn’t exist. The SH3 gene in combination with genes SH5, SH6, SH7, SH8, SH9 and SH? would be very important to obtain cultivars with more durable resistance to the rust.Item Selection for durable resistance to leaf rust using test-crosses on IAPAR-59 and Tupi IAC 1669-33 cultivars of Coffea arabica(Instituto de Tecnologia do Paraná - Tecpar, 2007-07) Sera, Gustavo Hiroshi; Sera, Tumoru; Ito, Dhalton Shiguer; Azevedo, José Alves de; Mata, João Siqueira da; Doi, Deisy Saori; Ribeiro Filho, ClaudionorThe aim of this study was to identify plants of the IAPAR-59 and Tupi IAC 1669-33 coffee cultivars with less defeated resistance genes by the rust races present at IAPAR (Londrina, Paraná State, Brazil) using test-crosses. Eighteen test-crosses derived from hybridizations between ‘IAPAR-59’ or ‘Tupi IAC 1669-33’ with susceptible coffee to the rust disease were evaluated. Six hybrids were used as susceptible standards originated from hybridizations between two susceptible coffee plants. Many parental plants of the ‘IAPAR-59’ and ‘Tupi IAC 1669- 33’ presented more defeated resistance genes against rust races present at IAPAR than others of these cultivars or the genes were in heterozygous, because of segregant susceptible plants observed in some test-crosses. The test- crosses were very efficient to identify plants with less defeated resistance genes to the H. vastatrix. Coffee plants considered resistants would must be made test-crosses to verify which plants presented less and/or more defeated genes in homozygous.