THE EFFECT OF NITRIC OXIDE APPLICATION ON THE GROWTH AND DEVELOPMENT OF SOYBEAN (GLYCINE MAX L. MERR.) GROWN UNDER HEAT STRESS

This study was conducted to determine the effects of nitric oxide (NO) application on the growth and development of soybean (Glycine Max L. Merr.) grown under heat stress. The experiment in the study was conducted using 84 pots, including the control group. The plants were administered nitric oxide with 10, 20, 30, 40, 50 and 60 mg/L doses, and were subjected to a heat stress of 10, 20, 30, 35, 40 and 45 degrees C. The seeds were selected from among robust and ready-to-germinate ones and they were germinated in the pearlite and in a climate chamber at 25 +/- 2 degrees C temperature. During the growth phase, the pots were irrigated with 100 mL 1/2 Hoagland solution at five days intervals. The plants, which had been subjected to heat stress and nitric oxide, were harvested at the 14th and the 28th days. The samples collected equally from each pot were wrapped in aluminum foils and stored at -86 degrees C. Later, the Proline, Chlorophyll, MDA and Ion (Na+, K+, Ca+, Cl-) analyses were conducted on the samples. Different results were obtained in the analyses depending on the applications. Due to the increasing heat stress and administered NO, statistically significant increases were found the proline, chlorophyll, MDA, and ion compositions of the soybean leaves. It was concluded that, an increase in durability and resistance occurred in soybeans grown under heat stress, depending on the administered doses, and the application had a positive effect on growth and development at the 40 mg/L and 50 mg/L nitric oxide doses.