Trigonelline inheritance in the interspecific Coffea pseudozanguebariae x C-liberica var. dewevrei cross

Trigonelline alkaloid is present in coffee beans, and during roasting it gi ves rise to the major coffee aroma compounds (several alkyl-pyridines and p yrroles). In this study we investigated the genetic inheritance of trigonel line accumulation in green beans in an interspecific cross between a wild e ast African species, Coffea pseudozanguebariae (PSE) and the west African s pecies C. liberica var. dewevrei (DEW). Trigonelline content was measured b y HPLC in both parental species, F-1 hybrids and the reciprocal backcross h ybrids (BCDEW and BCPSE). The results showed that, on average, PSE accumula ted twice as much trigonelline as DEW. No year effect or interaction (genot ype x year) was recorded. Trigonelline showed high heritability (71%), whic h meant that the genotypic value could be easily estimated from the phenoty pic value. However, the fact that this trait was not additive suggested the possibility of nucleo-cytoplasmic inheritance. This hypothesis was confirm ed by: (1) similar levels of trigonelline content in the PSE, Fl, BCPSE and BCDEW groups, all having the same maternal cytoplasm, and (2) the location of one nuclear QTL on the G linkage group.