ABSTRACT:The latex obtained from Jatropha curcas (physic nut) is used in traditional medicine to treat a variety of disturbs, including burns, hemorrhoids, ringworm and ulcers. Phytochemical analyses have shown that J. curcas latex contains natural compounds with therapeutic potential. In this study, the toxicity, cytotoxicity and genotoxicity effects of J. curcas latex on the root cells of Allium cepa were examined. Onion seeds and bulbs were exposed to seven different concentrations of latex and then the roots were submitted to macro and microscopic analyses. Water and sodium azide were used as negative and positive controls, respectively. The analysis of root growth showed that J. curcas crude latex or 50% diluted is highly toxic. Cytogenetic results showed that the mitotic index of the onion roots submitted to latex treatment decreased significantly compared to the negative control, which suggests that the latex is cytotoxic. High incidence of chromosome aberrations in the cells treated with J. curcas latex was observed too, indicating that the latex also presents genotoxic effect. The analyses presented in this report suggest the toxic, cytotoxic and genotoxic effects of J. curcas latex. Then, the indiscriminate use of J. curcas latex in folk medicine could bring risk to human health.

ABSTRACT:Latex from Jatropha curcas L. exhibits biotechnological potential for the development of biodiesel and drugs. Little is known about the collection methods and latex productivity of this species.In order to garner information on the use of J. curcas latex, factors that influence production by this species were assessed. As a result, no significant difference was found between the volume of latex production. Multiple regression analysis demonstrated that latex production is positively associated with plant height and negatively associated with fruit production and other variables that maximize it. During the fruiting process the plant uses most of the assimilates for fruit development and a lower percentage to produce secondary compounds, resulting in less availability of these metabolites for latex production. In general, the latex production obtained from this species is low and limits commercial exploitation of this compound, despite its possible pharmacological potential.

A Integração Lavoura-Pecuária (ILP) é uma alternativa para melhor exploração da terra durante o ano. Uma possível melhoria para este sistema é a inserção do feijão guandu anão (Cajanus cajan) visando o aumento no teor de proteína da pastagem durante o período de seca. O presente trabalho objetivou analisar a produtividade de biomassa de milho para silagem (Zea mays) em consórcio com braquiária (Urochloa ruziziensis) e diferentes densidades de feijão guandu. O delineamento experimental foi em blocos casualizados com sete tratamentos e quatro repetições, sendo eles: milho + braquiária + cinco densidades de feijão guandu (50 mil, 100 mil, 150 mil, 200 mil e 300 mil plantas por hectare), milho + braquiária e milho solteiro. A maior produtividade de massa seca do milho foi constatada com 100.000 plantas ha-1 de feijão guandu, porém, a massa fresca não foi afetada pela presença das diferentes densidades de feijão guandu, assim como observado na produção de massa da braquiária. A integração de milho, braquiária e feijão guandu se apresenta como atividade promissora por não afetar significativamente a produtividade de biomassa da cultura principal, usando-se até 200.000 plantas ha-1 de feijão guandu.

The efficiency of recurrent selection depends, among other factors, on the estimation of parameters that guide the breeder to obtain genetic gains for multiple traits. The aim of this research was to estimate genetic and phenotypic parameters of maize populations during the third cycle of recurrent selection for traits of interest. The populations CRE-01and CRE-02, potential for resistance to corn stunt, were described using genetic and phenotypic parameters of variance components, heritability, variation indices and correlation between 16 agronomic traits. Direct and indirect selection gains were estimated for each trait and considering the Smith and Hazel, Mulamba and Mock and Z index. Both populations have genetic variability for the traits. High heritability estimates were obtained for most of the traits, which associated with the genetic variability, indicate that these populations may show continuous gains with recurrent selection. All selection indexes provided satisfactory genetic gains, but the Z index was the most promising considering the results of both populations.