Keragaman Genetik Beberapa Genotipe Jarak Pagar (Jatropha curcas L.) Berdaya Hasil Tinggi Berdasarkan Karakter Morfologi, Agronomi, dan Isozim

Abstract

The interest in using Jatropha curcas L. from the family Euphorbiaceae for the production of biofuel is rapidly growing. The research objective was to determine genetic variation of several high yielding physic nuts based on their morphology, agronomy, and isozyme characters. The research used Completely Randomized Design with three replications. The treatment was consisted of 8 genotypes i.e. IP-1A, IP-1M, IP-2P, Lombok Timur, Lombok Tengah, Lombok Barat, Sumbawa, and Bima. Analysis of isozyme of the eight genotypes was also conducted according to 5 enzyme systems, i.e. peroksidase, esterase, aspartat aminotransferase, malat dehidrogenase, and alcohol dehidrogenase. Observation was done on qualitative and quantitative characters as well as banding pattern derivedisozymes. The results showed that genetic variation was low when based on qualitative characters and isozyme (0-25%) but relatively high when based on selected quantitative characters analysis (17-81%). Analysis of combined qualitative, quantitative, and isozyme characters still gave low genetic variation (6-33%). Based on the quantitative characters at similarity coefficient of 46% the genotypes can be devided into three clusters. Improved population genotypes, i.e. IP-1A, IP-1M, and IP-2P were placed in 3 different clusters, while other genotypes from NTB area were grouped in the same cluster. Therefore, selection among population of the same ecotype based on agronomic characters such as yield components, yield and oil content was suitable in Jatropha improvement, especially when genetic variation was low. Furthermore, introduction, mutation and crossing are suggested to increase genetic variation of current Jatropha collection.