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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Altered expression of the caffeine synthase gene in a naturally caffeine-free mutant of Coffea arabica(Sociedade Brasileira de Genética, 2009) Maluf, Mirian Perez; Silva, Carla Cristina da; Oliveira, Michelle de Paula Abreu de; Tavares, Aline Gomes; Silvarolla, Maria Bernadete; Guerreiro Filho, OliveiroIn this work, we studied the biosynthesis of caffeine by examining the expression of genes involved in this biosynthetic pathway in coffee fruits containing normal or low levels of this substance. The amplification of gene-specific transcripts during fruit development revealed that low-caffeine fruits had a lower expression of the theobromine synthase and caffeine synthase genes and also contained an extra transcript of the caffeine synthase gene. This extra transcript contained only part of exon 1 and all of exon 3. The sequence of the mutant caffeine synthase gene revealed the substitution of isoleucine for valine in the enzyme active site that probably interfered with enzymatic activity. These findings indicate that the absence of caffeine in these mutants probably resulted from a combination of transcriptional regulation and the presence of mutations in the caffeine synthase amino acid sequence.Item IAC Catuaí SH3 - a dwarf Arabica coffee cultivar with leaf rust resistance and drought tolerance(Crop Breeding and Applied Biotechnology, 2019) Fazuoli, Luiz Carlos; Braghini, Masako Toma; Silvarolla, Maria Bernadete; Gonçalves, Wallace; Mistro, Júlio César; Gallo, Paulo Boller; Guerreiro Filho, OliveiroThe cultivar IAC Catuaí SH3 was developed by the pedigree method, from the recombination of the coffee tree H 2077-2-5-46, of the Catuaí Vermelho germplasm, with accession IAC 1110-8, from the exotic cultivar BA10. Cultivar IAC Catuaí SH3 is high-yielding, resistant to coffee leaf rust and tolerant to drought.Item IAC Obatã 4739 – dwarf arabic coffee cultivar with yellow fruits and resistant to leaf rust(Crop Breeding and Applied Biotechnology, 2018-07) Fazuoli, Luiz Carlos; Braghini, Masako Toma; Silvarolla, Maria Bernadete; Gonçalves, Wallace; Mistro, Júlio César; Gallo, Paulo Boller; Guerreiro Filho, OliveiroCultivar IAC Obatã 4739 was derived from a cross between coffee tree IAC 1669-20-1 and cultivar Catuaí Amarelo IAC 62. It is short and high-yielding, rust-resistant, has large and yellow fruits, medium to late maturation, excellent cup quality, and responds effectively to irrigation.