Analisis Genetik Singkong (Manihot esculenta Crantz) Mutasi Sinar Gamma Menggunakan Marka Molekuler

Abstract

Cassava (Manihot esculenta Crantz) is a major food commodity in Indonesia, but conventional breeding is limited by low genetic variability. This study analyzed the genetic diversity of the M1V2 mutant of the Tambak Urang variety resulting from 50 Gy gamma irradiation using the RAPD-PCR technique to support the development of superior varieties. The samples consisted of 11 clones (1 control U0 and 10 mutants) from the BRIN collection, whose leaf DNA was extracted and amplified with 10 RAPD primer (OPK-1 to OPU-13). Analysis using NTSYS-pc with UPGMA and Jaccard similarity yielded 39 DNA bands (54.29% monomorphic, 45.71% polymorphic); primer OPK-15 was the most informative (85.71% polymorphism). The dendrogram formed 4 clusters: stable clones (U67-1, U85-1, U128-1 identical to the control), moderate mutation (U60-3, U98-1; similarity 0.8), and high mutation (U177-1, U192-4; similarity 0.6). Morphological changes (stem/leaf color, branching) correlated with genetic divergence, with no significant effect on tubers. The results indicate that gamma rays effectively induce polymorphism, with potential for selecting cassava germplasm adapted to marginal lands.