The effects of gamma-rays on the growth and yield of twelve mutant lines of Zingiber
officinale Roscoe from 2 varieties; namely Bentong and Tanjung Sepat were analysed for
a second (M1V2) and a third generation (M1V3). Mutant rhizomes have previously been
exposed to different doses (0, 5, 7, 9, 11, and 13 Gy) of gamma-rays that were propagated
until the third generation. In the study, the phenotypic characteristic and genetic variation
study using Randomly Amplified Polymorphic DNA (RAPD) of ginger mutant lines of
M1V2 and M1V3 were analysed and compared with the first generation (M1V1). Parameters
such as sprouting rhizome, plant height, the average number of leaves and shoots, average
length and width of leaves, and average weights of rhizomes per plant for mutant lines of
both varieties were collected. It was observed that the increase in dosage had a negative
effect on the growth performance of plants. The number of leaves and shoots, length and
width of leaves and average weight of rhizomes for both generations were decreased as
the dose increased. The plants from the treatment 5 Gy dose produced the highest ginger
rhizome yields of 65.45±1.35 g and 165.0±2.30 g in the Bentong and Tanjung Sepat
varieties respectively, after nine months of cultivation in M1V2. While in M1V3, the
rhizome yield at 5 Gy showed that the highest rhizome yields were reduced in both
varieties of Bentong (45.45±1.25 g) and Tanjung Sepat (125.0±2.30 g). The PCR-based
RAPD analysis showed 98.29% of polymorphism which indicated genetic variations
between ginger mutant lines. The information provides an important input in determining
resourceful management strategies for genetics improvement of ginger.