Print version ISSN 0006-8705
SANTOS, João Francisco dos et al. Resistance to late leafspot in F4 populations selected from crosses between the cultivated peanut and an Arachis amphydiploid. Bragantia [online]. 2011, vol.70, n.3, pp. 512-518. Epub Sep 09, 2011. ISSN 0006-8705. http://dx.doi.org/10.1590/S0006-87052011005000001.
Resistance to late leafspot (Cercosporidium personatum) was evaluated under field conditions in F4 plant populations selected from crosses between Arachis hypogaea genotypes (accessions VGaRoSv 12549 and VGaRoSv V12548 and the cultivar IAC Caiapó) and a synthetic amphydiploid (Arachis ipäensis x Arachis duranensis)4x. The experiment was carried out during 2007/2008 in Pindorama, State of São Paulo. Ninety and three F4 families were evaluated in plots of ten plants distributed along three-meter rows, with two meters spacing between rows. Cultivars IAC Caiapó and Runner IAC 886, as well as the wild species A. ipäensis and the amphydiploid were used as references (control). Some morphological and agronomic attributes were also evaluated as indicators of proximity between the wild parent and the cultivated peanut. Disease resistance variability was studied through estimates of AUCDP (Area Under the Curve of Disease Progress). The results showed that the amphydiploid used in these crosses is an interesting source of resistance. Selection by the pedigree method yielded F4 resistant individuals at the level of the wild resistant parent, but the chances of obtaining resistant plants with agronomic desirable traits is small, indicating the need for backcrossings.
Keywords : Arachis hypogaea; crossings; Arachis amphydiploid; Cercosporidium personatum; resistance.