CONTROLLING ELEMENTS IN A TRIBAL MAIZE FROM COLOMBIA: Fcu, A TWO-UNIT SYSTEM

[摘要] The genetic basis for a striking aleurone color variegation of a maize population from Colombia is described. The variegation is the result of the interaction of a particular r allele, designated r-cu , and a specific factor, Fcu (Factor Cuna), that collectively compose a controlling element system. In the absence of Fcu , a variable dilute (nonvariegated) pigmentation is expressed in the aleurone. The degree of variegation is determined by differences in the dosage of the Fcu element; differences in variegation between kernels with one r-cu vs. two r-cu 's cannot be detected. Because of the specificity of the interaction, Fcu is different from the three other well-known controlling elements, Dt, Ac and En (= Spm ), and therefore represents a fourth controlling element system in maize. In addition to Fcu , the Cuna tribal maize contains two other controlling elements, Dt and a very weak En . The prevalence of controlling elements in natural maize populations is discussed.

[学科分类] 医学（综合）