Abstract
This experiment was conducted in the laboratories of the Seed Testing and Certification Division-Babylon province in 2018 in a completely randomized design (CRD) with four replicates and two factors. The first factor included the addition of polyethylene glycol 6000 (PEG 6000) with three levels of water stress of 0 bar, -6 bar, and -9 bar which are herein denoted by S1, S2, and S3, respectively. The second factor included three stimulation treatments of wheat seeds by soaking the seeds in the plant hormone, Brassinolide for 24 hours with concentrations of 0 mg liter-1, 2 mg liter -1, and 4 mg liter-1 which are denoted by B0, B1, and B2, respectively. The results showed that water stress adversely affected wheat seedling characteristics. With the water stress level S2, the lowest average period of germination initiation was 3.33 days, germination period was 3.38 days, drought resistance index at germination reached 1.01, total chlorophyll content was 27.91 mg/100 g fresh weight, and gibberellin content was 29.8 micromolar. The treatments with Brassinolide achieved a significant improvement in plant characteristics where B2 treatment realized the lowest average period of germination initiation of 2.58 days and drought resistance index during germination of 1.11. B2 treatment also achieved 22.13% increase in total chlorophyll content, 66.53% increase in gibberellin content, and 43.81% increase in Indole-3-acetic acid (IAA) compared to the control treatment B0 without Brassinolide.
