Introduction: Considering the importance of self-reliance in rice production, the necessity and importance of creating and introducing high-quality cultivars that are short and resistant to dormancy, early-high-yielding among local qualitative cultivars is inevitable. In this regard, the deputy of the rice research institute in Mazandaran (Amol) with the cooperation of Karaj Nuclear Agriculture Research Institute used gamma rays (doses of 200, 250 and 300 gy) on the seeds of Tarom Mahali, Hassani, and Anbarbo varieties to advance M1 population to M5. In this research, several promising mutant lines were selected in terms of the agricultural traits of early ripening, and shortness with suitable performance examined in an observational experiment in Amol and compared to their parents (Tarom Mahali, Hassani, and Anbarboo) along with Fajr and Shiroudi.
Materials and methods: To evaluate the sixth generation (M6) mutants, an experiment was carried out in the field of the deputy of the rice research institute in Mazandaran (Amol), in the form of a randomized complete block design with three replications in the crop year of 2017. The number of mutants of 32 genotypes along with three parents (Tarom Mahali, Hassani, and Anbarboo) and two chack, Fajr and Shiroudi, were evaluated for a total of 37 genotypes. By measuring the traits of the number of days to 50% flowering, plant height, number of panicles in the hill, and yield of the lines were compared. After harvesting, a 400-gram sample of rice from each treatment and replication was selected and transferred to the quality laboratory. The characteristics of milling recovery, head rice percentage, grain elongation ratio, amylose percentage, and gelatinization temperature were measured.
Results: The results showed that the decrease in plant height in the lines obtained from Anbarboo was more than the Tarom Mahali, and the height of the selected mutants was 100-130 cm. 18 mutants had an average number of panicles (13.6-17.7) and had no significant difference at the 1% level. By increasing the number of days to 50% flowering and the number of panicles in the hill, the yield of rice genotypes was increased. Among the mutants, numbers 138, 1126, and 3200 had the highest milling recovery and were statistically similar to the Tarom Mahali. The percentage range of head rice among mutants was 60-70%. 9 mutants had a grain elongation ratio greater than 2. The range of change in amylose percentage and gelatinization temperature among the mutants was 16.5-22.5 and 3.7-7, respectively.
Conclusion: Mutant genotypes numbered 114, 1117, 1120, 1126, 126, 138, 222, 2212, 2310, 3200, 3216, 3218 and 3227 had higher performance than the parental check (Tarom Mahali, Hassani and Anbarboo). In addition, these mutants had better milling recovery and higher grain elongation ratio than the check cultivars. |
