The effect of different levels of radiation was determined using four set-ups-10kR, 30kR, 50 kR, and the control (no radiation). The four set-ups were observed for nine weeks and growth (in cm), germination, and survival rate was measured. Results showed that at the right level of radiation level (10 kR), radiation have a positive effect on the plant growth and has the same germination and survival rate from the control set up. The 30 kR set up and 50 kR set up are relatively smaller in growth than the control set up. Thus, increasing the radiation level above 10 kr corn inhibits its growth in terms of height and decreases the percent germination ofcorn (Zea mays L.) but with right amount of radiation at 10 kr radiation has a positive effects in terms of growth.
According to (Mendioro, Laude, Barrion, Diaz, Mendoza, & Ramirez, 2010), Mutations are changes in the genetic material that are heritable and essentially permanent. Mutations either may be spontaneous, or induced by physical or chemical agents. Ionizing radiation such as X-rays, protons, neutrons and alpha, beta, and gamma rays from radioactive sources like radium and cobalt-90, X-rays and other ionizing radiation is one of the common mutagenic agents that break DNA strand which produce chromosome breaks rather than base changes (Ramirerz, Mendioro, & Laude, 2010). Ionizing radiation can penetrate tissues and undergo ionization forming ions.
These ions undergo chemical reactions to have a stable chemical configuration. While doing these, ions produce breaks in chromosomes, (DNA) which induce mutation (Das, 2006). The biological effect of ionizing radiation depends mainly on the amount of energy absorbed by the biological system of which, of course, the chromosomes are the most target (Harten, 1998). However according to Wort (1941) as cited by (Sax, 1955) wheat seeds irradiated with low doses of X rays produced larger plants than the control.
The study aimed to determine the effect of different levels of radiation on plant growth in corn (Zea mays L.). The specific objectives were: 1.To observe the effects of different levels of radiation on plant growth in termes of height, germination, and survivability, and 2.To explain the observe effects of radiation in corn (Zea mays L.) to its growth.
MATERIALS AND METHODS
To assess the result of different levels of radiation in plant growth of corn, corn seeds were irradiated at varying doses: 10 kR,30 kR, and 50 kR. These irradiated seeds were at the same time and the same place including the control set-up. For nine weeks, the data for plant growth (cm), germination rate(%), survivability rate (%) were collected and tabulated.
RESULTS AND DISCUSSION
As seen in Table 1, results show that the the set-up that was irradiated with 30 kR and 50 kR ended the lowest percent germination while the set-up that was irradiated with 10 kR was the same with the control based on percent germination which is 100%.
At the first date of observation, the lowest in average height is the set-up that was irradiated with 50 kR. With the same date and place of planting, you can conclude that radiation has an effect to the plant growth, germination, and survival of the plant.
You can see at the Graph 1 that the control set-up and the 10 kR set-up are almost the same but in the end of the graph, the 10 kR set-up was the highest in terms of average plant height. At 50 kR, the plant cannot survive anymore due to the radiation and no data was recorded because the survival rate is 0% means all the plants in the 50 kR was dead. Unlike in the 10 kR, 30 kR set-ups was relatively lower than 10 kR setup in terms of plant growth, survival rate and germination rate. Plants have some resistant to some radiation because plants do not have lotions and sunblocks and they need sunlight for photosynthesis and we know that the sun emits UV rays.
SUMMARY AND CONCLUSION
The effect of different levels of radiation was observed by irradiating corn seed using three different setups-10 kR, 30 kR, and 50 kR. Data was collected and shown. Thus, there is a certain level of radiation that can make a plant grow more. In this experiment, we conclude that at 10 kR, corn plants grow better because of mutation. Furthermore, this experiment is subjected to further reseach to improve the conclusion that at certain level radiation, plants grow better.
Das, L. D. (2006). Genetics and Plant Breeding. New Age International Ltd. Harten, A. M. (1998). Mutation Breeding: Theory and Practical Applications. Cambridge University Press. Mendioro, M. S., Laude, R. P., Barrion, A. A., Diaz, M. Q., Mendoza, J. C., & Ramirez, D. A. (2010). Genetics: Laboratory Manual 12th Revision. 7 Lakes Printing Press. Ramirerz, D. A., Mendioro, M. S., & Laude, R. P. (2010). Lectures in Genetics Ninth Edition. 7 Lakes Printing Press. Sax, K. (1955). The Effect of Ionizing Radiation on Plant Growth. American Journal of Botany, 360-364.