Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhao manso, is a highly promising species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia. We have made the first genetic evaluation of J. curcas collected from Brazil. Our objective was to quantify genetic diversity and to estimate genetic parameters for growth and production traits and seed oil content. We evaluated 75 J. curcas progenies collected from Brazil and three from Cambodia. The mean oil content in the seeds was 31%, ranging from 16 to 45%. No genetic correlation between growth traits and seed oil content was found. However, high coefficients of genetic variation were found for plant height, number of branches, height of branches, and stem diameter. The highest individual narrow-sense heritabilities were found for leaf length (0.35) and width (0.34), stem diameter (0.24) and height of branches (0.21). We used a clustering algorithm to genetically identify the closest and most distant progenies, to assist in the development of new cultivars. Geographical diversity did not necessarily represent the genetic diversity among the accessions collected. These results are important for the continuity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds.

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.

The development of technologies will certainly contribute to boost the commercial exploitation and domestication of Spondias tuberosa. The objective of the present study was to identify morphophysiological effects of gibberellin on the growth of S. tuberosa seedlings. The experiment was conducted in a greenhouse at the Goiás State University, Brazil, using 300-day-old S. tuberosa seedlings planted in 12-liter pots containing soil (Typic Hapludox), sand, and manure (3:1:0.5). The experiment was conducted in a completely randomized design, with five replications and six treatments consisting of single foliar applications of 30 mL plant-1 of solutions with different gibberellin (GA3) concentrations (0, 150, 300, 450, 600, and 750 mg L-1), using a manual sprayer. The plants were evaluated at 60 days after the applications. The maximum biomass accumulation in S. tuberosa seedlings was found with the use of 415 mg L-1 of GA3. The use of gibberellin accelerated the vegetative growth of S. tuberosa plants and enabled the formation of seedlings with better root system and xylopodium, and aerial parts with greater number of leaves, leaf area, and stem weight.

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 collected in the stem and the branches. With respect to environmental characteristics, climatic conditions, such as low temperatures and rainfall, affected production. The period of low temperatures and leaf fall occurs after fruit harvest and, in the absence of strong sinks, the plant can use the assimilates to generate greater 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