Regulation of Growth and Physiological Properties of Fragrant Rice Seedlings by Hydrogen-Rich Water (HRW) Under Nitrogen-Deficient Conditions

Hydrogen-rich water (HRW) has been shown to improve the growth of rice under stressful conditions. However, the effects of HWR on the growth and development and stress resistance physiology of fragrant rice seedlings under nitrogen deficiency conditions are not clear. A pot experiment was conducted by using two fragrant rice varieties i.e., Yuxiangyouzhan and Xiangyaxiangzhan as materials. In this experiment, two nitrogen (N) treatments (LN: 1/4 strength of Kimura nutrient solution and MN: full strength of Kimura nutrient solution) and two HRW treatments (CK: Kimura nutrient solution without H 2 and HRW: Kimura nutrient solution contains 500 ppb H 2 ) that are four treatments including MN-CK, MN-HRW, LN-CK and LN-HRW for each variety. Treatments were applied at the two-leaf stage of fragrant rice and morphological and physiological and biochemical attributes were investigated at 5 and 10 day after treatment (DAT). The results showed that, under nitrogen deficiency conditions, the HRW treatment promoted the growth of fragrant rice seedlings in terms of increased biomass of the whole seedling at 10 DAT. Compeared LN-CK, LN-HRW treatment increased malondialdehyde content of shoot of Yuxiangyouzhan and Xiangyaxiangzhan, increased catalase activity of root at 10 DAT of Yuxiangyouzhan, increased peroxidase activity at 5 DAT of Xiangyaxiangzhan. It can be seen that HRW is able to reduce the stress of low nitrogen on fragrant rice to some extent, and that the reduction of this stress is largely dependent on improving the growth rate of fragrant rice seedlings and increasing the activity of representative antioxidant enzymes.