Judul: Genetic analysis of morpho-agronomic characters of selectively-bred jatropha (Jatropha curcas L.) based on quantitative and molecular approaches.
Abstrak: The recent scarcity of fuel has stimulated many efforts to remove dependence on petroleum oil by finding alternative sources of new and renewable energy so that its availability can be predicted and renewable. Jatropha curcas L. has been chosen as a source of biofuel that has an important role as a petroleum oil substitute, especially for producing biodiesel, as Jatropha seeds have an oil content of up to 35% with oleic acid and linoleic as the main components. This renders Jatropha seeds suitable for use as a biofuel. Development of Jatropha as a biofuel is still hindered by the lack of variety which is economically profitable. Possible efforts for the development of Jatropha in Indonesia include: exploration of Jatropha plants from various regions of Indonesia, introducing the plants from abroad and plant breeding. The purpose of this study was to understand the genetic diversity of the parental and the first generation (F1) Jatropha plants based on morphological and molecular markers. More over was to investigate the correlation between morpho-agronomic traits on the seed productivity and the oil content of the second generation (F2), as well as to obtain potential candidates of Jatropha genotypes producing seeds with high content of oil and high seed productivity. The experiment was conducted at the Biotech Center, BPPT and Department of Agronomy and Horticulture, Bogor Agricultural University from November 2011 to January 2013. The study divided into three stages. The first stage was to formulate hypothesis on genetic diversity and heritability of morpho-agronomic characters of the parental and F1 Jatropha plants. The second stage was to analyze the genotypic similarity of the parental and F1 Jatropha plants based on molecular markers, and the third stage was to analyze the correlation of morpho-agronomic characters on the F2 Jatropha plants. There were 16 parental and F1 genotypes of Jatropha used in this study, with the experimental design was a complete randomized block. Five plants were used from each genotype, with three replications. Results of this study showed that genetic diversity of morpho-agronomic characters on the parental and F1 Jatropha plants was relatively narrow, with genetic diversity coefficient of 2.73% to 9.02%. The broad-sense heritability was high for all characters, ranged from 32.26% to 85.89%. In this study among the 16 parental and F1 genotypes of Jatropha had no morpho-agronomic characters which directly correlated to productivity and seed oil content. Characters that can be chosen as a selection criterion to obtain the total dry weight of a high seed were the number of fruit and the total seed number per bunch. Based on the similarity analysis of 15 genotypes of Jatropha against 33 loci of Random Amplified Polimorphic DNA (RAPD) marker, it demonstrated that vii similarity coefficient matrix was ranging from 0.36 to 1.00. The lowest coefficient value (0.36) was found between genotype LMPxPDI and JGY, as well as between LMPxPDI and JGY. While the highest coefficient value (1.0) was found between genotype KMRxKMR LMPxLMP. RAPD marker-based dendrogram classified the 16 Jatropha genotypes into four groups at the similarity coefficient of 0.72. Group I, III and IV consisted of only
Keyword: heritability, genetic variability coefficient, genetic variance, phenotypic diversity