RESUMO
Bulked segregant analysis was used to identify simple sequence repeat (SSR) markers associated with pod and kernel traits in cultivated peanut, to permit rapid selection of superior quality genotypes in the breeding program. SSR markers linked to pod and kernel traits were identified in two DNA pools (high and low), which were established using selected F2:6 recombinant individuals resulting from a cultivated cross between a runner (Tamrun OL01) and a Spanish (BSS 56) peanut. To identify quantitative trait loci (QTLs) for pod and kernel-related traits, parents were screened initially with 112 SSR primer pairs. The survey revealed 8.9 percent polymorphism between parents. Of ten SSR primer pairs distinguishing the parents, five (PM375, PM36, PM45, pPGPseq8D9, and Ah-041) were associated with differences between bulks for seed length, pod length, number of pods per plant, 100-seed weight, maturity, or oil content. Association was confirmed by analysis of segregation among 88 F2:6 individuals in the RIL population. Phenotypic means associated with markers for three traits differed by more than 40 percent, indicating the presence of QTLs with major effects for number of pods per plant, plant weight, and pod maturity. The SSR markers can be used for marker assisted selection for quality and yield improvement in peanut. To the best of our knowledge, this is the first report on the identification of SSR markers linked to pod - and kernel- related traits in cultivated peanut.
Assuntos
Arachis , Arachis/genética , Estações de Separação/análise , Frutas , Polimorfismo Genético , Repetições Minissatélites/genéticaRESUMO
Ilex paraguariensis is used in Brazil as a stimulating beverage called "mate". Leaves and immature fruit extracts of Ilex paraguariensis were evaluated for their radical scavenging capacity, total methylxanthine and polyphenol contents. Antimicrobial activity of two enriched saponin fractions obtained from the fruits were also evaluated. The radical scavenging activity of the fractioned extracts was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The IC50o of L-ascorbic acid, ethyl acetate and n-butanol fractions from the leaves and ethyl acetate fraction from the fruits were 6.48 microg/mL, 13.26 microg/mL, 27.22 microg/mL, and 285.78 microg/mL, respectively. Total methylxanthine content was 1.16 +/- 0.06 mg/g dry weight in the fruits and 8.78 +/- 0.01 mg/g in the leaves. Total polyphenol content varied from 86.82 +/- 3 x 10(-4) to 199.91 +/- 3 x 10(-3) mg/g in leaf fractions and from 54.25 +/- 1 x 10(-3) to 110.36 +/- 4 x 10(-4) mg/g in fruit fractions. Enriched saponin fractions from the fruits showed no antimicrobial activity. To our knowledge, this are the first data available on the antioxidant/antimicrobial activities and polyphenol/methylxanthine contents of Ilex paraguariensis fruits.