Downy mildew (Plasmopara viticola) is the main grapevine disease in

The aim of the present work was to physicochemically characterize the fruits of accessions of feijoa [Acca sellowiana (O. Berg.) Burret] active germplasm bank (BAG), located in São Joaquim, Brazil. The identification of accessions with desirable fruit traits will facilitate species breeding and cultivation. During seven harvests (2004-2017), 10 fruits per plant of 229 accessions were evaluated for fruit diameter, length and weight, skin and pulp weight, skin thickness, pH, titratable acidity, and soluble solids content, in addition to the qualitative descriptors insertion of sepals, fruit shape, sheen of skin, vacuum, color of skin and pulp, and texture and roughness of the skin. Descriptive statistics, correlations, and a multivariate analysis were applied to better understand the nature and magnitude of the variables. The mean +1SD was used to identify the best accessions for breeding purposes. Active germplasm bank accessions revealed significant phenotypic diversity for the physicochemical characteristics of the fruits, and the year effect represented the largest contribution to the variance for all evaluated characteristics, except fruit length. The characteristics total fruit weight, fruit diameter, and skin thickness are strongly related to pulp yield (%). There is high phenotypic diversity in accessions of feijoa conserved in the São Joaquim BAG, which will allow different traits of this species to be genetically improved.

The objective of this work was to use a marker-assisted selection for pyramiding the resistance loci Rpv1 and Rpv3.1 in grapevine (Vitis vinifera), and to evaluate their conferred resistance against Brazilian downy mildew (Plasmopara viticola) isolates. A progeny of 23 plants, segregating for the two resistance loci, was obtained by the cross between the Gf 2000-305-122 and Gf.Ga-52-42 genotypes. The progeny was genotyped with four microsatellite markers and phenotyped for resistance to P. viticola using a bioassay with leaf discs. Six plants containing the Rpv1 and Rpv3.1 pyramided loci were identified by the molecular analysis. Plants harboring the Rpv1 + Rpv3.1, Rpv3.1, and Rpv1 loci showed 12.8, 30.0, and 33.1 sporangiophores per leaf disc, respectively. Plants with no resistance loci showed a dense sporulation. The phenotypic analysis of the expression of the two pyramided loci was only confirmed for four plants that showed the highest resistance level, i.e., mean value of 1.8 sporangiophores. A high-throughput method for pyramiding the Rpv1 and Rpv3.1 loci was developed, which confirmed the increased resistance to P. viticola. The selected elite genetic material shows a high resistance to downy mildew and elevated enological potential for grapevine breeding in Brazil.

El cacao (Theobroma cacao L.) es uno de los principales cultivos de importancia económica en el Ecuador, principalmente para los pequeños y medianos agricultores del litoral. Sin embargo, las enfermedades fungosas reducen el rendimiento de este cultivo. Durante los años 2008 a 2011 se evaluó en las localidades Quevedo y Tenguel, el comportamiento de 10 clones experimentales de cacao tipo Nacional con el objetivo de seleccionar los de mayor productividad y tolerancia a dos enfermedades: moniliasis (Moniliophthora roreri) y escoba de bruja (Moniliophthora perniciosa), en comparación con dos testigos comerciales (EET-103 y CCN-51). El diseño experimental fue de bloques completos al azar con arreglos factorial, con cuatro repeticiones. Se registró el número de escobas de bruja vegetativas, porcentaje de mazorcas enfermas, número de mazorcas sanas y totales, así como el rendimiento de almendras secas de cacao. El clon comercial CCN-51 presentó la menor incidencia de enfermedades, así como la mayor producción de mazorcas sanas y rendimiento promedio de almendras (1047.7 kg ha-1). Cuatro clones experimentales presentaron características deseables: L46-H57 con una mayor producción de mazorcas sanas y totales, L21-H43, L46-H57 y L46-H88 con un rendimiento de almendras superior a 550 kg ha-1, L18-H58 con el menor número de escoba de bruja (7.3), y L21-H43 con la menor incidencia de mazorcas enfermas (37.0 %). Estos clones pueden ser utilizados en programas de mejoramiento y conservación. La incidencia de enfermedades fúngicas y el rendimiento de almendras secas de cacao fueron mayores en Quevedo que en Tenguel.