عدد نماذج التداخل الجيني العاملة في النبات النامي تحت عوامل الشد

Abstract

To acquire more information on genotype x environment interactions in plants grown under abiotic and/or biotic stresses, and to understand a new approach on the complex mechanism of tolerance, a formula was set-up to estimate the number of genes interactive models (NGIM) acting in plants under stress. Some of previous results and ideas on this topic were taken into consideration, including morpho-physiological traits and molecular approaches. The formula was: NGIM= n2-x, when n= number of stress variables and x= n-1. Genes of stress variables were sketched as circles, and the sectors of each group of genes and their interactions were identified. Sketches explained that in two stress variables, these sectors will appear, as two of genes groups acting alone, and one sector represents their interaction. If three variables taken, there will be seven sectors, three of them of genes groups acting alone, three sectors of two groups interactions, and one sector of three groups interaction. In case of four variables, four sectors will be of genes groups acting alone, four sectors of two groups interactions, four sectors of three groups interactions, and one sector of the four groups interaction (total 13). In case of five variables taken, the sectors will be 21, in case of six variables taken, the sectors will be 31, and for seven variables the sectors will be 43. Sectors of eight variables will be 57, namely, 8 sectors of genes groups acting alone, 8 sectors of two groups interactions, 8 sectors of three groups interactions, 8 sectors of four groups interactions, 8 sectors of five groups interactions, 8 sectors of six groups interactions, 8 sectors of seven groups interactions, and one sector for the eight groups interaction. However, using this formula for any number of stress variables will give similar trend of interactions. The results of applying this formula showed the complexity of multi-gene actions and interactions in plants grown under stress variables. This implies the need of a larger area of plots to grow thousands of genotypes individuals repeated under several levels of that stress, several traits taken under study, and genetically wide genotypes, planted in a honeycomb design to enable the breeder identifying tolerant individuals and/or genotypes under those environments.