Selection of Coffee Progenies With Large Beans Resistant to Rust and Cercospora Leaf Spot

Abstract

<p>Rust is the main disease of coffee. Recently, cercospora leaf spot has grown in importance, intensifying defoliation and decreasing grain yield. The aim of this study was to use a mixed model approach to select the best progenies of "Big Coffee VL" for resistance to rust and cercospora leaf spot. We used 12 progenies with high bean yields. Based on bean size, leaves and plant size, plants within each progeny were classified as "small" (P), "medium" (M) and "large" (G). The experimental design was completely randomized, with six replicates and one plant per plot. Six measurements were carried out every 15 days for each plant by selecting 20 fully exposed leaves with higher and lower sun exposures. The measurements summarized disease severity using two diagrammatic scales to obtain the area of the leaf under rust or Cercospora leaf spot. A mixed model approach was used to calculate genotypic value (GV) and heritability estimates. The Mulamba and Mock index was used to select the most resistant progenies, in which the sum of rankings was weighted by a heritability value. Five progenies were selected; three progenies were G (G17, G9, and G12), one progeny was M (M5) and another progeny P (P23). Among these, M5 and P23 progenies are the most productive and may have potential use in future studies. The statistical approach used to predict promising genotypes facilitates the selection of genetically superior individuals for maximizing yields.</p>

Physiological aspects and yield in coffee progenies with large beans

“…Recent studies have shown genetic variability between "Big Coffee VL" progenies, regarding disease resistance, bean size, yield, besides physiological and anatomical characteristics (Castanheira et al, 2016;Pereira et al, 2019;Silva, 2016). In this study, it is possible to observe this variability among the progenies through graphic dispersion, shown in Figures 3 and 4, which was similar to the grouping by Tocher's optimization method.…”

Physical and sensorial quality of arabica coffee cultivars submitted to two types of post-harvesting processing

“…Regarding physical quality, the results found in this study corroborate a study carried out by Krohling et al (2018) who evaluated the adaptation of arabica coffee cultivars in the mountain region of Espírito Santo, Brazil, observing differences as a function of grain size. In this way, it is possible to select genotypes with greater uniformity of grain size, and higher percentages of chato graúdo sieves (Pereira et al, 2013;Rodrigues et al, 2014;Cardoso et al, 2016), having in view of the fact that obtaining coffee beans from high sieves can promote greater aggregation of value to the product, in addition to being related to greater productivity and appreciation of the product in the international market (Pereira et al, 2013;Borém et al, 2020). In a study carried out with progenies from the crossing of Catuaí and Icatu cultivars and descendants of Híbrido de Timor, the progenies that presented the highest averages for the sieve characteristic "17 and above" were those that also presented higher productivity (Pinto et al, 2012).…”

Diseases affecting the coffee crop: Elucidating the life cycle of Rust,Thread Blight and Cercospora Leaf Spot

“…comercial 'Sarchimor MG 8840' presenta resistencia a la enfermedad, seguida de otros genotipos de la colección Sarchimor, seguida de individuos de la colección de germoplasma (Botelho et al, 2017). Otras fuentes de resistencia son las reportadas por Pereira et al (2019), quienes describen al cultivar 'Big Coffee VL' por presentar características de grano largo, y sus progenies 'M5' y 'P23' poseen buenas características de producción y un alto potencial de resistencia a C. coffeicola. Aunque se puede encontrar información sobre resistencia genética en café contra C. coffeicola, ésta aún no ha sido explorada a profundidad (Botelho et al, 2017).…”