Abstract

It is important to determine precisely salt effects on bud germination. In this study, an in vitro procedure was used for studying sugarcane bud germination under NaCl salinity stress with different concentrations (0, 17, 34 and 68 mM) using five cultivars: NCo310, CP70-321, CP65-357, CP66-346 and CP59-73. Germination percentage of control ranged from 75% for variety CP66-346 to 100% for variety CP65-357 after 8 days of culture. Salt stress reduced the rate of germination in all varieties.  At the end of the 8th day, salt stress decreased the percentage of final germination at all NaCl concentrations used and for all varieties except variety CP66-346 which showed a stimulation of germination at 34 mM NaCl. However, NaCl stress effects on bud germination of the five varieties used in this study were very low with an average reduction of 9.22; 5.88; 5.71 and 1.04 % in the presence of NaCl, respectively, for NCo310, CP70-321, CP65-357 and CP59-73; a little increase (3.08 %) was observed for CP66-346. Thus, NaCl stress delayed buds germination and globally reduced the percentage of final germination. Varieties CP59-73 and CP66-346 appeared to be more salt tolerant at this stage than the three other varieties.

Key words: In vitro culture, sugarcane, Saccharum sp., buds germination, salt stress.