Determination of the effective radiation dose for mutation breeding in purple carrot (Daucus carota L.) and possible variations formed

Abstract

Plant breeding allows altering the genetic structure of plants to meet human needs. The use of radiation technology for inducing mutations and -thereby-new phenotypic variants has become increasingly common as a tool for developing new crops. The aim of this study was to determine the effective gamma irradiation dose for inducing mutations in purple carrot. For this purpose, increasing gamma radiation doses [0, 50, 100, 200, 300, 400, 500, and 600 Gy] were applied to purple carrot seeds. The irradiated seeds were sown in pots and the emergence and survival rates of the seedlings were analyzed. Considering plant emergence (%) as a response variable, the LD 50 dose was 387.5 Gy. Analysis of root length, root width (shoulder diameter) and plant height in control (0 Gy) and irradiated plants (50-600 Gy) revealed an inverse association between these morphological traits and radiation dose. SRAP and ISSR markers were used to identify DNA polymorphisms in irradiated and control plants. The range of amplicons per primer set revealed by ISSR and SRAP markers was 4-10 and 2-13, respectively. In ISSR analysis, the average Nei's gene diversity, Shannon's information index, and PIC value ranged from 0.13 to 0.25, from 0.20 to 0.35, from 1.39 to 1.67 for eight doses, respectively. In SRAP analysis, the average Nei's gene diversity, Shannon's information index, and PIC value were ranged from 0.15 to 0.25, from 0.23 to 0.37, from 0.43 to 0.58 for eight doses, respectively. Cluster analysis revealed three main groups; a) non-irratidated (control) plants, b) plants from the 600 Gy dose, and c) a third group with two subgroups: one with individuals from the lowest irradiation doses (50-200 Gy) and a second group with individuals from the highest irradiation doses (300-500 Gy).

Morphological, Histological and Genetic Evaluation of Gamma Radiation-Induced Mutation and Its Potential Application in Rudbeckia hirta (L.)

“…Also, several studies have demonstrated that higher doses of irradiation do not always lead to greater genetic changes in plant genomes [36][37][38]. Our results affirm that utilizing combined data from SCoT and CDDP techniques is effective for detecting and assessing genetic diversity among mutants.…”