Summary: Cross-compatibility studies inArachisL. have brought to light possible new sources of genes for introgression in cultivated peanuts. A total of 32 different crosses were made, using accession V14957 ofA. gregoryiC.E. Simpson, Krapov. & Valls as the female parent andArachisspecies containing seven distinct genomes as male parents. The 3167 pollinations resulted in 153 confirmed inter and intraspecific hybrids. Viability estimates of paternal pollen by staining (PVS) varied from 46.75 to 99.17%, while the pollen count of the hybrids varied from 0.3 to 43.6%, this highest PVS resulting from an intraspecific combination, which suggests appreciable variability in accessions ofA. gregoryi. Viability estimates of paternal pollen by germination (PVG) resulted in consistently lower values for all materials, ranging from 41.91% to 88.00%.Arachis gregoryiis important to expand the available diversity of species associated with the peanut B genome; it has a potential to be incorporated as a parent in crosses that aim to expand the genetic base of peanuts and may be useful for concentrating important genes in pre-breeding lines associated with the B genome.

Resumen: Estudios de compatibilidad cruzada enArachisL. han sacado a la luz posibles nuevas fuentes de genes para introgresión en el maní cultivado. Se hicieron un total de 32 cruzamientos distintos, utilizandoA. gregoryiC.E. Simpson, Krapov. & Valls accesión V14957 como progenitor femenino y especies deArachisque contienen siete genomas distintos como progenitores masculinos. Las 3167 polinizaciones resultaron en 153 híbridos inter e intraespecíficos confirmados. Estimaciones de viabilidad del polen paternal por tinción (PVS) variaron de 46.75 a 99.17%, mientras que el recuento de polen de los híbridos varió de 0.30 a 43.60 %, ese PVS más alto resultando de una combinación intraespecífica, lo que sugiere variabilidad apreciable entre accesiones deA. gregoryi. Las estimaciones de viabilidad del polen paterno por germinación (PVG) resultaron en valores consistentemente más bajos para todos los materiales, que van desde 41.91% a los 88.00%.Arachis gregoryies importante para expandir la diversidad disponible de especies asociadas con el genoma B del maní; tiene el potencial de incorporarse como progenitor en cruzamientos que apuntan a la expansión de la base genética del maní y puede ser útil para concentrar genes importantes en líneas de pre-mejoramento asociadas al genoma B.

Abstract Peanut (Arachis hypogaea L.) is an important oilseed crop and food legume that is highly susceptible to biotic and abiotic factors. Wild Arachis species represent useful genetic resources because of their resistance to pests and diseases. In particular, understanding the affinity between B-genome species is important for broadening the genetic base of A. hypogaea (AABB genome), since only one population of A. ipaënsis is known, and relatively few other species have been described. Therefore, we aimed to determine the genomic affinity between A. ipaënsis and A. williamsii by developing hybrids. Microsatellite markers verified the hybrid status, and chromosome pairing and pollen viability results revealed that the species share high genomic affinity. Additionally, the presence of dyads detected in sporad and pollen analyses indicated the production of 2n gametes. These results will be useful for performing evolutionary studies and developing strategies for introgression programs to improve the B genome of A. hypogaea.