Karakterisasi Morfologi dan Pertumbuhan Ubi Kayu ‘Gajah’ Asal Kalimantan Timur Hasil Iradiasi Sinar Gamma

Abstract

Cassava (Manihot esculenta Crantz.) is one of important food source, therefore it is very important to increase cassava yield and starch content, and decrease HCN content in the tuber through efficient breeding program. High genetic diversity is one requirement in successful breeding program. The objective of this experiment was to increase genetic variability of ‘Gajah’ genotype cassava from East Kalimantan through gamma irradiation. Stem cuttings of cassava were irradiated in PATIR-BATAN and planted in Cikabayan Experimental Field, IPB from December 2012 to June 2013. This research was arranged in randomized completely block design with one factor that was gamma ray irradiation rate. The gamma irradiation rate consisted of five levels i.e. 0, l5, 30, 45, and 60 gray (Gy). The research results showed that the LD20 was 16.04 Gy and the LD50 was 21.49 Gy. Gamma irradiation did not significantly affect the vegetative growth of cassava, but it caused changes in several morphological characters, i.e. pubescence on apical leaves, color of apical leaves, leaves retention, shape of central leaflet, petiole color, number of leaves lobes, and orientation of petiole. One of mutant candidate from 15 Gy-irradiated plants produced 17 tuber per plant, thus it is potentially developed further.