Detection of changes in growth, yield and genetic variation using RAPD markers among M1V2 and M1V3 generations of irradiated ginger (Zingiber officinale Roscoe)

The effects of gamma-rays on the growth and yield of twelve mutant lines of Zingiberofficinale Roscoe from 2 varieties; namely Bentong and Tanjung Sepat were analysed fora second (M1V2) and a third generation (M1V3). Mutant rhizomes have previously beenexposed to different doses (0, 5, 7, 9, 11, and 13 Gy) of gamma-rays that were propagateduntil the third generation. In the study, the phenotypic characteristic and genetic variationstudy using Randomly Amplified Polymorphic DNA (RAPD) of ginger mutant lines ofM1V2 and M1V3 were analysed and compared with the first generation (M1V1). Parameterssuch as sprouting rhizome, plant height, the average number of leaves and shoots, averagelength and width of leaves, and average weights of rhizomes per plant for mutant lines ofboth varieties were collected. It was observed that the increase in dosage had a negativeeffect on the growth performance of plants. The number of leaves and shoots, length andwidth of leaves and average weight of rhizomes for both generations were decreased asthe dose increased. The plants from the treatment 5 Gy dose produced the highest gingerrhizome yields of 65.45±1.35 g and 165.0±2.30 g in the Bentong and Tanjung Sepatvarieties respectively, after nine months of cultivation in M1V2. While in M1V3, therhizome yield at 5 Gy showed that the highest rhizome yields were reduced in bothvarieties of Bentong (45.45±1.25 g) and Tanjung Sepat (125.0±2.30 g). The PCR-basedRAPD analysis showed 98.29% of polymorphism which indicated genetic variationsbetween ginger mutant lines. The information provides an important input in determiningresourceful management strategies for genetics improvement of ginger.