Radiosensitivity of rice to gamma irradiation in Costa Rica

• Published in: Cultivos tropicales Vol. 43; no. 1
• Main Authors: Madriz-Ma, Fernandez-Acuna, Alexis, Hernandez-Villalobos, Silvia, Orozco-Rodriguez, Rafael, Arguello-Delgado, Juan
• Format: Journal Article
• Language: English
• Published: Editorial Universitaria de la Republica de Cuba 01.01.2022
• ISSN: 0258-5936

Induced mutations have been used for the genetic plant breeding. A previous step to this is the material radiosensitivity study to be worked on, since it allows observing the effect on the plant material and defining the adequate dose. The aim of this work was to determine the radiosensitivity of rice seeds (Oryza sativa L. var CR5272), subjected to gamma irradiation with [.sup.60]Co. Seven doses were evaluated: from 100 to 700 Grays (Gy) with increments of 100 Gy, compared with a control without irradiation (T0). The variables were evaluated: at seven days, germination percentage and at 21 days, stem and root length. Variable values decreased as the irradiation dose increased. The highest germination and stem length occurred at 100 and 200 Gy; however, neither had a statistical difference with respect to the control; root length increased by 12.74 %, with 100 Gy irradiation, in relation to the non-irradiated treatment. The median lethal dose (L[D.sub.50]) was established at 674 Gy for germination percentage, 380 Gy for stem length and 274 for root length. The correlation between radiation levels and stem and root length (R=0.92 and R=0.85) was significant, but not for germination (R=0.54). Radiosensitivity was achieved for rice seeds (Oryza sativa L. var CR5272) and a range of 300-400 Gy of irradiation was established as an effective dose, adequate to induce favorable mutations in this variety. Key words: cobalt, LD, plant breeding, mutation