Our main objective was to analyze the protection provided by Mycorrhiza (Rhizophagus intraradices) to Jatropha curcas plants under cold stress, through the analysis of physiological and oxidative stress parameters. Mycorrhizal (AM) and non-mycorrhizal (nonAM) plants were exposed to cold stress 4±1 ºC temperature for 72 h. The control plant grow at 25 ±1 ºC. Under cold stress, the stomata conductance decreased both AM and nonAM plants and photosynthetic efficiency only in non AM plants. The CAT activity increased in AM plants independently of stress conditions. GR activity shows a typical rise to cold stress in nonAM plants and decreased in AM ones. With cold stress, the APX activity was reduced in all treatments and SOD activity was not affected in all treatment The MDA content increased in nonAM plants while in AM plants it was unaffected by low temperature. This study reported on the regulation of antioxidant compounds, their relationship to the AM symbiosis and cold stress in Jatropha curcas L.

Jatropha curcas L. and Jatropha macrocarpa Griseb. (Euphorbiaceae) are perennial species adapted to marginal conditions not suitable for agriculture, and have been recently exploited for oil and biodiesel production. The anatomy of different organs in members of this family exhibits a wide range of variations. However, knowledge\ud of anatomical features is still incomplete. The aim of the present work was to analyze the anatomical structure of stem, leaf and root of J. curcas and J. macrocarpa seedling cultivated in a greenhouse. Fixed samples were properly treated using triple stain hematoxylin, safranin and fast green. Primary roots were diarch and triarch in J.\ud curcas, whereas in J. macrocarpa were diarch and the cortex showed parenchyma cells, larger in J. macrocarpa than J. curcas. Stem cortex was thicker in J. macrocarpa than in J. curcas. Both species had parenchyma cells with cystolith, chloroplasts, laticifers and starch granules, these being more abundant in J. macrocarpa. Leaves\ud were characterized by dorsoventral anatomy, with the epiderm showing amphistomatic condition with high stomata density at the lower surface. Both Jatropha species had paracytic stomata. Druses and non-articulated branched laticifers were recorded in the mesophyll. Some of the different anatomical features of J. curcas and J.\ud macrocarpa could explain the different tolerance to abiotic stress

curcas L. y J. macrocarpa Griseb. son arbustos perennes cuya mayor importancia principalmente es su potencial como biocombustible. Varios autores consideran que el tegumento de las semillas es uno de los factores que inducen la latencia. El objetivo del trabajo fue estudiar el papel del tegumento y el ácido abscísico (ABA) y el ácido jasmónico (JA) en la latencia y germinación de estas especies. J. macrocarpa presenta latencia ya que no germina por métodos tradicionales. En consecuencia, las semillas de J. macrocarpa fueron sometidas a diferentes tratamientos para romper la latencia de las semillas: T1) Control; T2) Escarificación con papel de lija; T3) Eliminación total del tegumento; T4) Inmersión en agua hirviendo; T5) Alternancia de agua caliente y fría; T6) Inmersión en H2SO4 concentrado durante 15 min; T7) Inmersión en H2SO4 concentrado durante 30 min; T8) Estratificación en papel húmedo y frío; T9) Estratificación en arena húmeda y fría. Después de cada tratamiento, las semillas se colocaron en placas de Petri que contenían agua destilada a 30°C de temperatura. Los porcentajes de germinación (GP) se determinaron durante 30 días. Se utilizaron 20 semillas por tratamiento, con tres repeticiones cada una. El ABA y el JA fueron extraídos y purificados de los tegumentos de ambas especies de Jatropha. Estas hormonas se identificaron y cuantificaron a partir de tejido mediante cromatografía líquida de alto rendimiento (HPLC)-espectrometría de masas (MS) de fase inversa. La eliminación total de tegumento mostró un aumento del 50% en el porcentaje de germinación, con los otros tratamientos se logró entre 0-10%. Los JA fueron el compuesto más abundante detectado en el tegumento. El nivel de ABA fue mayor en J. curcas (628%) que en J. macrocarpa, por esta razón suponemos que el nivel de ABA no está directamente relacionado con la germinación y/o dormancia de estas especies de Jatropha. Por el contrario, el nivel de JAs fue mayor en J. macrocarpa (101%) que en J. curcas. En efecto, el JA podría tener un papel en la inhibición de la germinación de semillas de J. macrocarpa.

J. curcas and J. macrocarpa are useful for restoring degraded areas and their seeds contain oils for biodiesel production. The aim of the work was to determine the reserve substances in the endosperm and the embryo of J. curcas and J. macrocarpa which is important in understanding the germination process, the establishment of these species and its industrial employment. Seeds were imbibed in distilled water for 24 h, to facilitate removal of seed coat with the aim to separate the embryo and nutritive tissues. In both species, the endosperm contained aleurone grains consisting of a crystalloid and globoid, lipids of red color and the starch was not observed. Four major fatty acids were determined in J. curcas seed: oleic, palmitic, stearic, palmitoleic and oleic fatty acid represents about 70% oil content. Oleic acid was the most abundant in J. macrocarpa seeds, while, there was not palmitoleic acid. Seed with predominantly unsaturated fatty acids is ideal for biodiesel industry. The means of the sugar content were: 14.3 µg/mg in endosperm and 104.76 µg/mg in embryo of J. curcas and 6.48 µg/mg in endosperm and 59.20 µg/mg in embryo of J. macrocarpa. The means of the protein content were: 4.2 µg/mg in endosperm and 45.02 µg/mg in embryo of J. curcas and 3.26 µg/mg in endosperm and 31.08 µg/mg in embryo of J. macrocarpa. Sugar and protein contents of Jatropha seeds were significantly higher in embryo in both species

To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper we study in comparative form structure of the seed, the importance of tegument in dormancy, the effect of accelerated aging on seed germination and viability, and the early and late growth in J. curcas and J. macrocarpa. External morphology of the seeds allow difference and internally also the embryos show evident differences. J. macrocarpa germination is around 0% -4%. The total removal of tegument showed a 50% increase and the other treatments between 0% -10%. Aging accelerated by Tetrazolium test allowed a comparative analysis of VP and GP. J. curcas maintains both to 96 h, while J. macrocarpa the seed viability is registered along the all treatment. J. macrocarpa seeds have less synchronicity than those of J. curcas. ABA and JAs were detected in tegument of J. macrocarpa and J. curcas seeds. JA could have a roll in inhibition of germination of J. macrocarpa seeds. Early and late growth, FW and DW of root, hypocotyl, epicotyl and leaf of J. curcas were significantly different in both species.