Agronomic characters and antioxidant enzyme characteristics of Oryza officinalis Wall in Huaiji

【Objective】This study was conducted to clarify the differences of agronomic characters and activities of antioxidant enzymes in leaves, stems and roots between Oryza officinalis Wall in Huaiji and cultivated rice Zhonghua 11 at different growth stages under natural growth conditions, which would provide theoretical basis for further exploring the valuable resistance genes and breeding resistant rice varieties.【Method】The seeds of O.officinalis Wall in Huaiji and Zhonghua 11 were germinated and cultured in nutrient solution under natural condition.The seedlings were transplanted until three-leaf stage, and the growth morphological indexes were measured.The seedlings were continued to be cultured with Mucun B nutrient solution under natural light.The leaves, stems and roots were sampled to determine the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) at the day 30 after transplanting and the day 10 after heading.【Result】O.officinalis Wall in Huaiji showed significant lower seed germination percentage(45.83%) as compared with Zhonghua 11(97.65%) (P< 0.05, the same below), the time growing to three-leaf stage was also significantly longer than Zhonghua 11.The plant height and above-ground height of O.officinalis Wall in Huaiji were significantly higher than that of Zhonghua 11, but the root length, above-ground weight and root weight were significantly lower than that of Zhonghua 11.There were great differences in plant growth phenotype between O.officinalis Wall in Huaiji and Zhonghua 11 at different growth stages, as to the wider leaf, longer leaf length, larger leaf angle, less tiller number, underdeveloped root system, smaller number of panicles and grains and slow grain filling in O.officinalis Wall in Huaiji.In addition, SOD activities in leaves and stems of O.officinalis Wall in Huaiji were significantly lower than those in Zhonghua 11, and the root SOD activity of O.officinalis Wall in Huaiji was significantly higher than that of Zhonghua 11 at day 30 after transplanting.The POD activity of leaves and stems of O.officinalis Wall in Huaiji was higher than that of Zhonghua 11 at day 30 after transplanting, and lower than that of Zhonghua 11 at day 10 after heading, while the root POD activity was significantly lower than that of Zhonghua 11 at these two growth stages.The CAT activity of O.officinalis Wall in Huaiji leaves were significantly higher than Zhonghua 11 at day 30 after transplanting, but the CAT activity of stems was significantly lower than that of Zhonghua 11at day 30 after transplanting and at day 10 after heading respectively, while the root CAT activity was significantly higher than that of Zhonghua 11 at these two growth stages.【Conclusion】The study showed that deep dormancy and low germination percentage are found in the seed of O.officinalis Wall in Huaiji.Significant differences are found in agronomic characters and growth phenotype between O.officinalis Wall in Huaiji and Zhonghua 11, companied with higher enzyme activity of POD and CAT at the key vegetative growth stage as compared to Zhonghua 11.It is suggested that O.officinalis Wall in Huaiji has the growth characteristics of high light efficiency leaf and excellent antioxidant properties, which may be used as high quality wild rice germplasm resources to play a role in efficient screening and utilization of valuable resistance genes in the future.