Germination of tomatoes under PEG-induced drought stress

Abstract

The aims of this study were: to assess the effects of drought stress on germination percentage, germination energy and number of days to complete germination in fifteen tomato populations; to distinguish the treatment that is the most suitable for classifying the tomatoes for their response to early-imposed drought; as well as to distinguish populations which could be used for breeding tolerant varieties. The experiment included control germination assay (distilled water) and the increasing (4, 8, and 12%, w/v) polyethylene glycol (PEG) treatments. Both germination percentage and energy considerably decreased with the increasing PEG treatments, while the observed average increase in the number of days required to complete germination remained statistically insignificant. The differences in germination among the populations were most pronounced in 12% PEG treatment, which is therefore recommended for further research. Several populations are indicated as tolerant; however, tomato drought tolerance exhibited as early as at the germination stage does not necessarily indicate the tolerance in later phases of plant development. The population 105 is recommended for breeding drought tolerant varieties.

Keywords

• drought tolerance
• germination
• Lycopersicon esculentum Mill.
• polyethylene glycol
• tomatoes