Abstract

Greenhouse and laboratory studies were conducted to examine the effects of allelopathic potential of wild barley shoot and root extracts on seed germination and seedling growth of five winter wheat cultivars. Plant materials containing 1.8, 3.6, 5.4, 7.2, 9.0 g shoot, and 3, 6, 9, 12, 15 g root were soaked in distilled water for 24 h. Then, the extracts were collected and filtered. Shoot and root extracts decreased germination percentage significantly and increased mean germination time partially only in Shiraz cultivar. The extracts at 80 and 100% concentrations reduced seedling growth parameters including shoot and radicle length and number of seminal roots. Root allelochemicals performed the more inhibitory effects than shoot ones. Darab-2 cultivar was the most tolerant and Shiraz cultivar was the most sensitive to wild barley extracts. Radicle length appeared to be the most sensitive morphological trait for allelopathic assessment of wheat seedling.

Key words: Plant interactions, allelopathy, wild barley, wheat, growth, extract.