Induced mutations for improving yield of capsium annuum L. using gamma radiation / Norumaimah Omar

Induced mutation via gamma radiation has been found to be a very useful technique in improving characteristics of crops. This study investigated on the effects of gamma radiation on germination, morphology, ultrastructure and yield of Capsicum annuitm L. var Kulai. Seeds of capsicum were radiated with gamma rays at various doses of 20, 40, 60, 80, 100, 200, 300, 400, 500 and 600 Gy. The rate of germinated seeds, shoot and root length were measured. Lethal dose on 50% population (LD50) was assessed. The effect of radiation on cell structures were observed using Scanning Electron Microscope (SEM). The results showed a significant difference in the seed germination rate between irradiated and non-irradiated seeds. The LD50 for capsicum (survival percentage) was determined at 325 Gy. The overall analysis revealed that the gamma radiation doses significantly increased plant phenotypic expressions such as fruit length, plant height, and flowers per axil only at the lower doses (20-80). The doses of 100, 200, 300 and 400 Gy have negatively affected the average number of fruits per plant (6.6, 7, 6.2 and 4.6 fruits, respectively) as compared to control (8.5). Germination rate, plant height, survival plant rate and other morphological characteristics of treated plant were increased at lower doses (40, 60 and 80 Gy). However, higher doses of 400-600 Gy caused decrease in germination and growth performance which resulted in plant death after two weeks of transplanting. Other than that, leaf structure on 100 Gy was described as "obcordate" apex while on 80 Gy was described a "undulate" edge. From the overall observation, it can be concluded that gamma rays affect seed germination, morphological characteristics and yield production of Capsicum annuun var Kulai. The most suitable dose that had improved yield of Capsicum annuum var Kulai was Treatment 4 (60 Gy) followed by Treatment 5 (80 Gy).