FIGURE 4 Effects ofElymus nutans extracts on germination of highland grasses. Values are mean ± SD(n=5). Different letters denote significant differences between treatments with a > b > c > d, the same below.
The root growth of drooping wildryegrass and Siberian wildryegrass was significantly inhibited by the three kinds of extracts, and the differences among extract treatments were not significant (Figure 5a). The effects of the three extracts on the root length of Chinese fescue, Kentucky bluegrass and crymophila bluegrass exhibited similar pattern, i.e. pieces extracts and root zone soil extracts presented stronger inhibition than whole extracts, but a slight difference in Kentucky bluegrass.
Except for Kentucky bluegrass, the three kinds of extracts significantly affected hypocotyl length of other four donor grasses (Figure 5b). The pieces extracts exhibited the strongest shoot growth inhibition on Chinese fescue, crymophila bluegrass, Siberian wildryegrass and drooping wildryegrass , and resulted in shoot length reduction by 42.9%, 31.1%, 21.0% and 25.6%, respectively.
The overall influence of different treatments on seedling dry weight of donor grasses was inhibition, varied with grasses and extracts (Figure 5c). The pieces extracts lead to significant seedling dry weight decrease of Chinese fescue, crymophila bluegrass, Kentucky bluegrass, Siberian wildryegrass and drooping wildryegrass with 42.9%, 34.7%, 30.2%, 27.1% and 26.9%, respectively. The root zone soil extracts presented similar effects of pieces extracts on Kentucky bluegrass, but similar effects of whole extracts on other four grasses.