Marinez Muraro Alves de Lima

Caffeine content of Ethiopian Coffea arabica beans

The coffee germplasm bank of the Instituto Agronomico de Campinas has many Coffea arabica accessions from Ethiopia, which is considered the primary center of genetic diversity in coffee plants. An evaluation of the caffeine content of beans from 99 progenies revealed intra- and inter-progeny variability. In 68 progenies from the Kaffa region we found caffeine values in the range 0.46-2.82% (mean 1.18%), and in 22 progenies from Illubabor region these values ranged from 0.42 to 2.90% (mean 1.10%). This variability could be exploited in a breeding program aimed at producing beans with low-caffeine content.

Evidência isoenzímica sobre a origem interespecífica do café Piatã

Years ago it was found in a field of Coffea arabica (2n = 44) a coffee tree different from any other known so far. Initially it was thought to be an autotetraploid either of C. liberica (2n = 22) or of C. dewevrei (2n = 22). Morphological and cytological studies of this tree and its progeny, designated by the prefix C387 of the Department of Genetics, IAC and named Piata, indicated that it was probably a natural hybrid originated from the fusion of a normal gamete (n = 22) of C. arabica and an unreduced gamete (2n = 22) of C. dewevrei. In the present study the isoenzyme banding patterns for the enzymes PGI, PGM and ADH of the seeds endosperm of Piata confirmed its interspecific origin. The alleles of combination of C. dewevrei and C. arabica for the aforementioned isoenzymes is peculiar and distinct for these species, and such alleles segregate in the seeds of the Piata. Isoenzymatic studies on seeds showed also that Piata coffee is self-compatible, and not self-incompatible as it was believed. Indeed, autogamy is quite frequent in the Piata coffee. Similar analyses may be useful for the identification of other natural hybrids among Coffea species. This could be of great value for genetic and evolution studies, and breeding of coffee, where the knowledge of the origin, genotype constitution and reproductive biology of the plants is important.