Multi-allelic nature of the locus controlling leaf marking in subterranean clover [Trifolium subterraneum L.; genetics]
1987
Tan, B.H. (Western Australia Univ., Nedlands. School of Agriculture) | Collins, W.J. (Western Australian Dept. of Agriculture, Perth. Pasture Improvement Branch)
The inheritance of leaf markings in subterranean clover (Trifolium subterraneum ssp. subterraneum) was studied in diallel cross involving a parental genotype with a leaf marking and 11 others, each with a distinctive marking. The results indicate Mendelian inheritance, and each marking appeared to be controlled by a different allele at a single locus. An alternative interpretation of the segregation data might be that the leaf mark locus is complex and comprises many tightly linked genes. Four types of dominance were manifest in the heterozygous combinations, including one that has not previously been described. With the exception of a completely dominant allele, the dominance relationships among the other alleles could not be predicted. Mutation appears to be the sole genetic mechanism by which new alleles arise. Their origin and evolution in subterranean clover is discussed with reference to Fisher's theory on the evolution of dominance.
Показать больше [+] Меньше [-]