Investigating the Effects of Drought Stress Induced by Polyethylene Glycol on Germination of some Indigenous Fenugreek Landraces (Trigonella foenum- graecum L.)

Drought is an event that happens due to lack of rainfall in a period of time. The occurrence of drought, reduces available soil water, but water losses through evaporation and transpiration is constantly increasing. The first stage of the plant, which may be faced with drought, is germinating. Since Germination begins with water uptake, lack of water at this stage in terms of duration and intensity of the stress causes or reduce germination percentage and germination rate. Because of the heterogeneity of soils in the field and lack of control of the environmental factors such as drought, laboratory research on the stress is considered. Some of these methods can be used to study the reaction of the landraces to the solutions from materials polyethylene glycol. This study aimed to investigate the characteristics of the native population of fenugreek germinating rate under drought stress conditions and identify landrace was incurred.

To investigate the effect of drought stress on germination and seedling growth characteristics of native landrace fenugreek, an experiment was conducted in a Completely Randomized Design with three replications in Seed Laboratory of University of Mashhad in 2014. The experiment treatments consisted of eight landraces of fenugreek of Esfahan, Tabriz, Hamedan, Sari, Challous, Amol, Mashhad and Yassooj on polyethylene glycol 6000 (PEG 6000) at four levels: (0, 3, 6 and 9 Bar) were replicated three times. The stress test for the simulation of polyethylene glycol 6000 was used and the amount of material needed to create each of the stress levels using the formula Michel and Kaufmann respectively. For control treatment distilled water was used. Landraces seed of fenugreek of Esfahan, Tabriz, Hamedan, Sari, Challous, Amol, Mashhad and Yassooj purchased. Before the start of the experiment, the seeds disinfest with a three percent solution of hypochlorite for two minutes to disinfect and then were washed three times with distilled water on the twelfth day, seeds and traits such as root length and root out the Petri measure.

In the study the interactions between landrace and drought, the rate of decline in most of the traits was related to native populations of fenugreek, Tabriz, Hamadan, Sari, Challous, Amol, Yasuj and Mashhad, respectively (-9 Bar) compared to control (0 Bar). As can be seen, the Isfahan landrace was more stable in most of the traits due to changes in drought levels. On the other hand, as the drought stress increased, the percentage and rate of germination of fenugreek seeds decreased. Fenugreek seed germination rate and percentage with increased drought stress the germination rate under drought stress signifcantly was higher than the percentage of germinating. The plants grow in different stages react differently to drought show seed germination and seedling production and a dry condition indicates that the plant is a potential for drought tolerance but that does not mean that the seedlings start to grow in dry conditions, can continue to grow in the same conditions.