Comparison Between Germinating Parameters of Basils (Ocimum Basilicum L.) and Pumpkin (Cucurbita Pepo L.) Under Drought Stress Conditions

Abstract

Drought stress is becoming an intimidating obstacle to global agriculture in the 21^st century, creating major food security challenges. Drought-sensitive crops, in particular, to which pumpkin and basils belong, reduce yield potentials. Lack of water can inhibit germination of sown seeds and manipulate germination parameters. An experiment was conducted to investigate the effect of drought stress, induced by (polyethylene glycol) (PEG), on some germination parameters (germination percentage, germination energy, germination rate index, mean germination time and root elongation) of pumpkin (Cucurbita pepo L.) and basil (Ocimum basilicum L.). The PEG concentration in both species was (2.5%) along with a control treatment (nutrient solution), on both species in three replicates of every treatment. Germinated seeds were counted every day at the same time, and the daily associated root elongation was measured by using a regular ruler. Each stage was considered finished when the average hypocotyl of the control treatment reached 3 cm long. Pumpkin took nearly 7 days to reach maximum root elongation, whereas basils took 8 days but failed to reach around 1.5cm root length and died. The results showed that basil seeds were extremely sensitive to water deprivation and could not germinate in 2.5% PEG solution, whereas pumpkin seeds germinated well in 2.5% PEG solution. It was found that the PEG treatment reduced germination by 25% in the case of pumpkin, whereas basils could not germinate well and the PEG treatment reduced germination by 75%. It demonstrates that pumpkins can withstand drought stress better than basils.