Abstract

S6-04

Biochemical Diversity of Carotenoids Accumulation in Cassava Storage Root

Boiteux M.E.N.F. and L.J.C.B. Carvalho

The central cylinder of the storage root (SR) of cassava has been considered solely as a source of starch. Some few reports, however, have indicated the presence of carotene in some yellow SR with variable amount of b-carotene.  This paper reports a further exploration of the diversity of this SR trait by collecting new germplasm of cassava SR with different colors in Amazon Basin, the center of origin and domestication of the crop.  Central cylinder of SR of cassava clones with colors varying from white, intense yellow, cream and pink were organized in a gene bank collection and their extracts analyzed in a HPLC system calibrated with carrot as standard.  The presence of lycopene and lutein were identified for the first time in SR of cassava and that the SR showed no presence of a-carotene.  The quantification analysis indicated 110 mg/gDWt of lycopene, b-carotene 42 mg/gDWt and lutein 22 mg/gDWt,  These results revealed biochemical diversities in the carotene biosynthetic pathway and the compartmentalization of the constituents in the SR of cassava.  Studies are underway to identify the genes coding for specific enzymes in the pathway.