MORPHOLOGICAL AND PHYSIOLOGICAL PERFORMANCE OF BROWN RICE (ORYZA NIVARA L.) UNDER SALINITY STRESS

Brown rice (Oryza nivara L.) is a potential a good source of antioxidants for health. Over the past several years, salinity tolerance has been the main aim of breeders for rice improvement. Salinity adversely affects crop growth and yield, and the use of tolerant cultivars is the only effective way to exploit the potential of saline land. This research aimed to analyze the morphological, physiological, and yield traits of brown rice cultivars under different salinity levels at the Kasa Rumah Sungai Balai Research Center, Rubber Research Center, Galang, Deli Serdang-North Sumatra, Indonesia. The said study was carried out during 2019 in a randomized complete block design (RCBD) and factorial arrangement with two factors, i.e., rice cultivars and salinty levels. Ten brown rice cultivars (Sipenget, Meulaboh, Beras Merah, Sijior, Kelik-3, Mesuji, Inpago-7, Sirap Merah, Fas Memeye, and Si Tappe), and four salinity levels (40, 80, and 120 mM and saline soil) were used and compared in the study. Brown rice cultivars and salinity levels significantly influenced plant height, grain weight, and peroxidase enzyme activity. However, the effects of both factors on leaves per plant and H2O2 in rice cultivars were nonsignificant. In rice cultivars, the most active enzyme was superoxide dismutase, which showed an increase of 1.20 units/mg of protein. Results revealed that brown rice cultivars exhibited varied responses to salinity stress levels. The rice cultivars Si Tappe, Kelik-3, Beras Merah, and Meulaboh revealed tolerance to salinity and showed good potential for growth and yield traits. The cultivars Mesuji and Inpago-7 were classified as the most sensitive and suceptible rice genotypes to salinity.