Variación hereditaria de líneas F2 de arroz (Oryza sativa L. ssp. indica) derivadas de un parental femenino portador del gen Clearfield

Abstract

In this experiment, F2 lines of rice (Oryza sativa L. ssp. indica) resulting from crosses with a female parent carrying the CREALFIELD gene, which confers resistance to the herbicide imazethapyr, were used. This study was carried out at the “San Pablo” Experimental Farm, Faculty of Agricultural Sciences, Technical University of Babahoyo, Ecuador. The objectives were: To evaluate the effect of the herbicide imazethapyr in F2 rice plants, segregating of a female parent carrying the CLEARFIELD gene and to select the F2 rice segregants plants tolerant and / or resistant to the herbicide imazethapyr. Complete Random Design was used with 24 treatments (11 progenies and 12 parents, 1 Control). Analysis of variance, graphs were performed to identify the individuals of interest and the Tukey test at 5% probability was applied to analyze the averages. The results showed that, the chlorophyll content differed between the progenies and the parental lines evaluated before and after the application of the herbicide. The degree of toxicity produced by the herbicide imazetapir, was minor affected to the female progenitor Br-101-UTB, which is the parental containing the resistant gene, obtaining a damage value of 1.15% (ALAM scale). Regarding the progeny, low grades were also obtained from 2.34 to 19.25%. This contrasted with the parentals which obtained ranges from 66.67 to 97%. The results express that the CLEARFIELD gene is easily and highly introgressive into the progeny when a parental with resistance acts as a female progenitor.