Скачать или смотреть Polygenic inheritance |Kernel colour in wheat| 12 th biology

The first experiment on polygenic inheritance was demonstrated by Swedish Geneticist H. Nilsson - Ehle (1909) in wheat kernels. Kernel colour is controlled by two genes each with two alleles, one with red kernel colour was dominant to white. He crossed the two pure breeding wheat varieties dark red and a white. Dark red genotypes R1R1R2R2 and white genotypes are r1r1r2r2. In the F1 generation medium red were obtained with the genotype R1r1R2r2. F1 wheat plant produces four types of gametes R1R2, R1r2, r1R2, r1r2. The intensity of the red colour is determined by the number of R genes in the F2 generation. Four R genes: A dark red kernel colour is obtained.Three R genes: Medium - dark red kernel colour is obtained.Two R genes: Medium-red kernel colour is obtained.One R gene: Light red kernel colour is obtained.Absence of R gene:Results in White kernel colour. The R gene in an additive manner produces the red kernel colour. The number of each phenotype is plotted against the intensity of red kernel colour which produces a bell shaped curve.
#Neetbiology #kernelcolourinwheat