Effects of microwave treatment on growth, photosynthetic pigments and some metabolites of wheat

Wheat (Triticum aestivum L. Sakha 61) grains were exposed to microwave radiation of a wavelength 2.85 cm and frequency 10.525 GHz for 15, 45, or 75 min. The exposed grains were germinated and then harvested after 7 and 14 d. While 15-and 45-min exposure of the grains stimulated seedling shoot length and fresh and dry masses, the exposure for 75 min had no pronounced effects. Fifteen and 75-min irradiation increased succulence and pigment contents in 7-and 14-d-old seedlings. While the ratios chlorophyll (Chl) a/b, carotenoids (Car)/Chl were higher in 7-d-old seedlings than in the control ones for all doses, they decreased in 14-d-old seedlings. The microwave radiation increased protein and amino acid contents, but decreased the contents of saccharides, nucleic acids, and phenolic compounds. Low dose (15 min) stimulated proline synthesis, whereas the other doses showed negative effect on its production