Acta Agronómica
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13094
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Item Comparison of fructification efficiency between reciprocal crosses in Coffea canephora(Universidad Nacional de Colombia, 2023-10-09) Ferrão, Maria Amélia Gava; Fonseca, Aymbiré Francisco Almeida da; Ferrão, Romário Gava; Volpi, Paulo Sérgio; Verdin Filho, Abrão Carlos; Rocha, Rodrigo Barros; Riva-Souza, Elaine ManelliThis study aimed to assess and compare the behavior of superior genotypes of Coffea canephora in terms of fruiting capacity using directed hybridizations in a full diallel design with reciprocals.Hybridizations were performed using 12 possible combinations between genotypes 02, 03, 23 and 83 from the Incaper breeding program. High estimates of the genotypic coefficient of determination in terms of the total number of pinheads per cross (TNP) and fruit set (FS) indicated variability of genetic nature. FS averaged 52,27%, ranging from 31,32% to 82,09%, with the higher rates relating to clone 23 as the male parent. Differences were found between reciprocal crosses in the combinations with genotype 23, which emerged as the donor plant with the best fruiting rate, but poor receiving ability. Clone 83 prevailed as the best receiving plant and the least effective donor. In the comparison of these two genotypes, antagonism was observed in their behavior when they were used as pollen-donor plants (male parents) and pollen-receiver plants (female parents), highlighting their possible maternal effect. Crosses involving clones 02 and 03 showed no differences when used reciprocally. The estimates of genotypic correlations were negative for the four associations involving the FS characteristic, being of greater magnitude with TNP.Item Phylogenetic relationship of coffee leaf rust in the central jungle of Peru(Universidad Nacional de Colombia, 2021-10-04) Gamarra Gamarra, Delia Palmira; Suarez, Gilberto Torres; Quiñonez, Charo Milagros Villar; McTaggart, Alistair R.; Lozano, Emerson Clovis CarrascoCoffee leaf rust is the main disease that causes significant losses in Coffea arabica. In Peru, this disease caused epidemics between 2008 and 2013 with production losses of 35 %. The objective was to identify H. vastatrix using a morphological and molecular approach based on a phylogenetic species concept. Coffee leaf samples with symptoms of chlorotic lesions with the presence of yellow uredospores at different severity stages of different cultivars were collected from 11 locations in the departments of Pasco and Junin during 2017-2018. DNA was purified as proposed by Cristancho and coworkers. The major subunit of ribosomal DNA was amplified with universal primers LR0R and LR5, and sequenced by Macrogen and deposited in GenBank. Sequences from the genera Achrotelium, Blastospora, Cystopsora, Hemileia, and Mikronegeria were included for phylogenetic analysis. The results showed that the rust was distributed in coffee growing regions of Pasco: Villa Rica (Catimor, Caturra, and Gran Colombia); Oxapampa (Yellow Caturra), and Junín: San Luis de Shuaro (Catimor), Chanchamayo (Catimor), San Ramón (Catimor), Vitoc (Caturra), Pichanaki (Caturra), Río Negro (Caturra), Pangoa (Yellow Caturra, Gran Colombia, Limani). It was also grouped into a single clade with isolated H. vastatrix from Mexico and Australia, suggesting that they come from a common ancestor. This is the first confirmed report using molecular barcoding of H. vastatrix in the central jungle of Peru.