LD50 AND GR50 ESTIMATION WITH GAMMA RAYS (60 Co) IN Arachis pintoi VAR. AMARILLO

Abstract

Objective: To estimate the median lethal dose (LD₅₀) and mean reductive dose (GR₅₀) due to gamma radiation in Arachis pintoi var. Amarillo seeds.

Design/methodology/approach: Ten doses were used (100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 Gy) plus a control (without radiation). The experimental design was completely random with three replications and 50 seeds per repetition. Seed germination was evaluated 29 days after sowing (das) and plant survival, plant height, root length and leaf area at 60 das. The LD₅₀ and GR₅₀ for survival and plants height were estimated by linear regression.

Results: There was a significant reduction of seed germination and plant survival from 300 and 200 Gy doses compared to the control (61.64 and 49.15 % each); for the plants height the dose was of 100 Gy (35.22 %). There were no differences in the root length and leaf area with 100 and 200 Gy regard to the control. The LD₅₀ was estimated at 212.54 Gy and the GR₅₀ at 162.16 Gy.

Findings/conclusions: The gamma radiation doses to induce genetic variation in A. pintoi var. Amarillo seeds were between 162 and 212 Gy.