Biblioteca do Café
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1
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Item Characterization of differential coffee tree hostsfor Hemileia vastatrix Berk. et Br. with RAPD markers(Crop Breeding and Applied Biotechnology, 2004-03-12) Teixeira-Cabral, Terezinha Aparecida; Sakiyama, Ney Sussumu; Zambolim, Laércio; Barros, Everaldo Gonçalves de; Silva, Dalza Gomes daEighteen clones of differential coffee tree hosts for Hemileia vastatrix Berk. et Br. were characterized with RAPD markers. The genetic distances were estimated and the genealogical origin of the clones compared to data of markerbased clusters. Thirty-five primers identified 158 polymorphic loci of RAPD markers. The cluster based on the matrix of genetic dissimilarity values was compatible with information on the genealogical origin cited in literature. Specific markers for a number of clones were identified, and a combination of 12 RAPD markers allowed the characterization of the studied clones.Item Additional physiological races of coffee leaf rust (Hemileia vastatrix) identified in Kenya(Sociedade Brasileira de Fitopatologia, 2012) Gichuru, Elijah K.; Ithiru, John M.; Silva, Maria C.; Pereira, Ana P.; Varzea, Vitor M.P.Coffee leaf rust (CLR), caused by the fungus Hemileia vastatrix, is among the most important diseases affecting coffee all over the world. In Kenya, it is currently the second most important disease, and breeding coffee to obtain new resistant cultivars has been a priority. Over time, new rust pathogenic races able to infect hitherto resistant coffee genotypes have been registered. To date, 49 races of the pathogen have been characterized all over the world. The most recent races to be characterized are able to infect derivatives of Timor Hybrid (HDT), which is a major source of resistance in breeding programs. This work aimed to identify new races of the pathogen in Kenya, emphasizing infected leaves sampled from CLR resistant varieties and breeding lines collected from two sites (Ruiru and Koru). Twenty-four samples were characterized, out of which 22 samples corresponded to new races of the pathogen. A total of six new races (III, XVII, XXIII, XXXVI, XLI and XLII) were characterized, revealing three new virulence genes (v1, v7, v8) and possibly a fourth virulence gene, the v9. This finding represents a serious threat to coffee production and also a challenge to coffee breeding programs that are in progress in Kenya.Item Agronomic performance of coffee in response to framework pruning in cycles of the “safra zero”(Editora UFLA, 2020) Maia, Pedro Lage; Tassone, Guilherme Augusto Teixeira; Nadaleti, Denis Henrique Silva; Botelho, Cesar Elias; Botelho, Deila Magna dos Santos; Moreira, Priscila Carvalho; Carvalho, Gladyston RodriguesIn this paper, we aimed at selecting genotypes of Coffea arabica L. that are responsive to framework pruning, with high productive potential and desirable agricultural features. We evaluated 18 progenies in the F5 generation, 8 of them being from the group Catucaí (breeding of seedlings of Red Catuaí with coffee seeds of the Icatu germplasm) and ten descendants from the Timor Hybrid (breeding of the Red and Yellow Catuaí with the Timor Hybrid), as well as two commercial cultivars as control (Tupi IAC 1669-33 and Obatã IAC 1669-20). The experiment was carried out at the experimental field of the Federal University of Lavras. The coffee was pruned in August 2014 after the sixth crop and once again in August 2016, being two cycles in the “safra zero” system. The design used was in randomized blocks (RBD) with three repetitions and 20 treatments (18 progenies and two commercial cultivars) totaling 60 experimental plots. We evaluated the area under the progress curve of incidence and severity of leaf rust and cercosporiosis, the productivity (sacs ha-1), sieve #16 and over (%), mocha-type grains (%) and apparent specific mass of grains (tonm-3). The genotype 12 (H516-2-1-1-18-1-4) was responsive to the framework pruning and kept its productivity stable in both pruning cycles, being efficient in such system of crop conduction, besides presenting low incidence and severity of coffee leaf rust and cercosporiosis and high sieve.