S. S. Angadi

Bio: S. S. Angadi is an academic researcher. The author has contributed to research in topics: Jatropha curcas & Crop yield. The author has an hindex of 2, co-authored 2 publications receiving 9 citations.

Identification of QTL markers contributing to plant growth, oil yield and fatty acid composition in the oilseed crop Jatropha curcas L.

Abstract: Economical cultivation of the oilseed crop Jatropha curcas is currently hampered in part due to the non-availability of purpose-bred cultivars. Although genetic maps and genome sequence data exist for this crop, marker-assisted breeding has not yet been implemented due to a lack of available marker–trait association studies. To identify the location of beneficial alleles for use in plant breeding, we performed quantitative trait loci (QTL) analysis for a number of agronomic traits in two biparental mapping populations. The mapping populations segregated for a range of traits contributing to oil yield, including plant height, stem diameter, number of branches, total seeds per plant, 100-seed weight, seed oil content and fatty acid composition. QTL were detected for each of these traits and often over multiple years, with some variation in the phenotypic variance explained between different years. In one of the mapping populations where we recorded vegetative traits, we also observed co-localization of QTL for stem diameter and plant height, which were both overdominant, suggesting a possible locus conferring a pleotropic heterosis effect. By using a candidate gene approach and integrating physical mapping data from a recent high-quality release of the Jatropha genome, we were also able to position a large number of genes involved in the biosynthesis of storage lipids onto the genetic map. By comparing the position of these genes with QTL, we were able to detect a number of genes potentially underlying seed traits, including phosphatidate phosphatase genes. The QTL we have identified will serve as a useful starting point in the creation of new varieties of J. curcas with improved agronomic performance for seed and oil productivity. Our ability to physically map a significant proportion of the Jatropha genome sequence onto our genetic map could also prove useful in identifying the genes underlying particular traits, allowing more controlled and precise introgression of desirable alleles and permitting the pyramiding or stacking of multiple QTL.

Effect of nitrogen and potassium fertilization on the production and quality of oil in Jatropha curcas L. under the dry and warm climate conditions of Colombia

Abstract: This study was conducted to assess fruit and seed yield, oil content and oil composition of Jatropha curcas fertilized with different doses of nitrogen and potassium in Espinal (Tolima, Colombia). The yields ranged from 4,570 to 8,800 kg ha -1 of fruits and from 2,430 to 4,746 kg ha -1 of seeds. These yields showed that the fertilizer dose of 150 kg ha -1 N + 120 kg ha -1 K increased fruit production by 92% and seed production by 95%, which represents an increase of about 100% in oil production, which increased from 947 to 1,900 kg ha -1 . The total oil content in the seeds ranged from 38.7 to 40.1% (w/w), with a high content of the unsaturated fatty acids oleic (> 47%) and linoleic acid (> 29%). The highest content of oleic acid in the seed oil was from the unfertilized control plants and plants with an application of 100 kg ha -1 of N and 60 kg ha -1 of K, with an average of 48%. The lowest content of oleic acid was registered when a low dose of nitrogen and a high level of potassium were applied at a ratio of 1:2.4 and doses of 50 kg ha -1 N + 120 kg ha -1 K, respectively. Low contents of the saturated fatty acids palmitic (13.4%) and stearic (7.26%) were obtained, making this oil suitable for biodiesel production. The nitrogen was a more important nutrient for the production and quality of oil in J. curcas than potassium under the studied conditions of soil and climate.

Effect of nitrogen and potassium on plant height and stem diameter of Jatropha curcas L. in Colombian tropical dry forest

Abstract: El uso de materias primas vegetales de Jatropha curcas L. para producir biocombustibles es de creciente interes en Colombia, mientras que hay poca informacion disponible sobre esta especie como cultivo. Este estudio evaluo la altura de la planta (Hp) y el diametro del tallo basal (BSD) de J. curcas segun lo afectado por las diferentes dosis de nitrogeno (N) y potasio (K) durante los primeros 435 dias de crecimiento (DAP). El experimento incluyo un diseno de medidas repetidas con factores de fertilizacion entre sujetos (dosis de N, dosis de K2O anidadas en la dosis de N) y un factor de tiempo de evaluacion. La Hp vario tanto en funcion de la dosis de N como de la dosis de K2O anidada en la dosis de N, obteniendose las plantas mas altas con aplicacion de 150 kg ha-1 N y 180 kg ha-1 K2O. Con los intervalos de confianza simultaneos de Bonferroni, se compararon los tiempos de evaluacion indicando para Hp intervalos no superpuestos a 435 DAP (150 kg ha-1 N y niveles restantes de este factor) y a 255 DAP (180 kg ha-1 K2O y el resto niveles de este factor). La aplicacion de fertilizantes N dio como resultado tallos mas gruesos en comparacion con las plantas de control. Los modelos de prediccion matematica se obtuvieron para Hp y BSD en J. curcas utilizando un analisis de regresion multiple. Estos modelos permiten en futuro predicciones rapidas y no invasivas del crecimiento de J. curcas en campo.