Genética de Coffea . XII — Hereditariedade da côr amarela da semente

Abstract

The known species of Coffea can be grouped into two categories according to the color of their endosperm which is either green or yellow. The commercially cultivated varieties of Coffea arabica L. and Coffea canephora Pierre ex Froehner are well known for the green color of their seed while the less known varieties of Coffea liberica Hiern and Coffea Dewevrei De Wild, et Th. Dur. have yellow Feed. In 1935, however, a yellow seeded type of C. arabica, was found in Brazil and has been described as Coffea arabica L. var. cera K.M.C. ; it is believed to have originated by mutation from Coffea arabica L. var. typica Cramer. In this paper the authors present the results of a genetic study of the yellow seeded mutant known as "cera". It has been found that in C. arabica, yellow endosperm is controlled by one pair of recessive factors cece. Hybrid seeds containing a Cece embryo were green (xenia), their endosperm being either Cecece or CeCece. Cera is a tetraploid variety and when it was crossed with diploid Coffea species having yellow endosperm, it was found to produce only yellow hybrid seeds. The cera, which is a yellow seeded mutant has been useful not only for definitely showing that the bulk of the coffee seed is true endosperm, but it has also proved useful is study of the biology of the coffee flower.