Rooting performance from leaf petioles of accessions and hybrids of wild Arachis species

Abstract

The genus Arachis has 69 species, the majority native to Brazil. Arachis spp. seedling root tips have been used to obtain dividing cells for cytological preparations. Several wild species produce small amounts of seeds and consequently few root meristems, making the cytogenetic characterization very difficult. The purpose of this study was to evaluate the rooting capacity of several wild species of Arachis using the detached leaves technique for obtaining roots from petioles. One hundred and thirty accessions and 27 interspecific hybrids were studied. Three evaluations were performed at 15, 31, and 49 days after planting. Leaf rooting observed in the wild species confirmed the great genetic variability typical of the Arachis genus, indicating that the number of days interferes with the rooting percentage. The Arachis Section presented the highest rate of rooting leaves. The Caulorrhizae Section showed the same pattern observed in the Erectoides Section. Accessions from Heteranthae, Trierectoides, Extranervosae, and Rhizomatosae Sections did not differ among each other. Differences were not observed in Erectoides Section when compared to Rhizomatosae and Extranervosae Sections. The number and morphology of roots obtained through this technique were promising to be used on cytological preparations. Key words: cytology, germplasm ENRAIZAMENTO DE PECÍOLOS DE FOLHAS DE ESPÉCIES SILVESTRES E HÍBRIDOS DE ARACHIS

Transference of multiple resistance to peanut through the development of cross-compatible complex hybrids of wild Arachis

“…The evaluation was done by the total damaged leaf area. According to data reported by Fávero et al (2005), in natural infestation under greenhouse conditions greater resistance to late leaf spot and rust was observed in amphidiploid and segregating individuals than in cultivated peanut. In agreement with studies on resistance to leaf spot and rust, resistance to these diseases is polygenic, complex, and probably con-…”

“…Different surveys of resistances in Arachis showed that the most interesting performances were detected in species that are not closely related to peanut (Stalker et al, 2016;Stalker, 2017). Moreover, the amphidiploids derived from species that are genetically closer to peanut, such as A. ipaënsis and A. duranensis (Fávero et al, 2005), did not show high resistance against most diseases and pests. By contrast, many of the amphidiploids derived from species that are genetically distant from A. hypogaea presented the highest resistances (Michelotto et al, 2016).…”