پاسخ جوانه زنی و رشد گیاهچه گیاهان دارویی زوفا (Hyssopus officinalis) و مارگاریت (Chrysanthemum superbum) به تنش خشکی

In order to study the effects of water stress on germination characteristics and seedling growth of two medicinal plants, two experiments were conducted at physiology laboratory of Faculty of Agriculture, Ferdowsi University of Mashhad as a completely randomized design with four replications. There were two types of medicinal plants; hyssop (Hyssopus officinalis) and marguerite (Chrysanthemum_superbum). Experimental treatments included five levels of water stress (۰, -۲, -۴, -۶ and -۸ bar). Results showed that the effects of different levels of water stress were significant on all of the studied indices of the two plants. Germination percentages decreased and mean germination time increased by increasing water stress levels. Germination percentage was minimum (۰%) in drought level of -۶ bar, in the two studied plants. Root length of Hyssop increased and Marguerite decreased by increasing water stress levels, respectively. Plumule length had a decreasing trend in the two studied plants, but the amount of this decrease was less in hyssop. Moreover, the root to plumule length ratio increased in hyssop and marguerite by increasing drought stress levels. Also, root dry weight increased, plumule dry weight decreased and root to plumule dry weight ratio increased by increasing drought stress severity in the two studied medicinal plants. Totally, the results of this experiment showed that germination and seedling growth indices were superior in hyssop in water stress conditions.

Keywords:

تنش اسمزی , گیاهان دارویی , میانگین زمان جوانه زنی , درصد جوانه زنی