NUTRIENT-UPTAKE AND GROWTH OF IN-VITRO COCONUT (COCOS-NUCIFERA L) CALLUSES

Growth of two strains, L1 and L7, of coconut calluses in vitro and changes in concentration of major nutrients and sugars in the media were measured after 0, 14, 28, 42 and 56 days of culture. A histological check was performed on days 0, 28 and 56. Although the calluses were multiplied on two different concentrations of 2,4-D, growth (dry weight) was identical for both strains and was linked to the same nutrient uptake. Organization of the meristematic zone of the calluses in the two strains was very different, but had no influence on their nutrition. NH4+, Ca2+ and Mg2+ uptake occurred throughout the culture period. Sucrose and SO42- were absorbed only during the lag phase of growth and at the beginning of the exponential growth phase. H2PO4- and NO3- uptake occurred only during the second half of the exponential phase. Ionic balance was maintained by K+ and Cl-.