© 2001 Heron Publishing—Victoria, Canada
Trueness-to-type and agronomic characteristics of Coffea arabica trees micropropagated by the embryogenic cell suspension technique
H. Etienne (1) and B. Bertrand (1, 2)
1. Centre de Coopération Internationale en Recherche Agronomique pour le Développement-Cultures Pérennes (CIRAD-CP), CIRAD, TA
80 / PS3, Boulevard de la Lironde, 34398 Montpellier Cedex 5, France / 2. Instituto Internacional de Cooperación Agrícola (IICA), Apdo 55, 2200 San José Costa Rica / Received September 15, 2000
Summary
Trueness-to-type and agronomic characteristics of trees of four coffee (Coffea arabica L.) F1 hybrid clones derived from embryogenic cell suspensions were compared with those of trees produced from in vitro microcuttings. Three types of variants were observed among the 644 trees derived from embryogenic suspensions. Total frequency
of the variants was 2.1% for trees originating from embryogenic cell suspensions, whereas no variant was found among the trees
produced from microcuttings. The variant known as "thick leaf" had thick leaves, many abnormally starry flowers and low yields
of large fruit. The "dwarf" variant was characterized by slow growth and small fruit. The "dwarf peaberry" variant had abnormal
seeds in a single cavity, in addition to the "thick leaf" and "dwarf" characteristics. Compared with normal trees, the variants
differed in leaf density and number of chloroplasts per guard cell. The variants aside, there were no differences in the main
agronomic characteristics between trees produced from embryogenic suspensions and those produced from microcuttings. For all
four clones, the trees had vegetative characteristics, productivity, fertility, and bean biochemical, mineral and organoleptic
characteristics that were identical to those of the controls. We conclude that it is possible to generate coffee trees commercially
with normal agronomic performance from embryogenic suspensions, because the frequency with which somaclonal variants occur
is limited.
Keywords:
coffee, field trial, microcuttings, somaclonal variation, somatic embryogenesis.
