Effect of seed discolouration (a complex disease) on seed quality parameters in paddy (Oryza sativa)

Abstract

The production and productivity of paddy (Oryza sativa L.) has been reported to be severely affected by an emerging disease called seed discolouration. It is a complex disease because several pathogenic fungi infect rice grains in the field. The infection reduces the seed quality by producing harmful mycotoxins that are hazardous to humans and animals. The current study was carried out from 2016–19 at IARI, New Delhi to determine the effect of seed discolouration on seed quality parameters in terms of physio-chemical changes. The findings revealed a significant loss in the seed quality of paddy in popular rice varieties. We observed a significant reduction in the germination percentage (9–42%), seedling length (3.4–33.3%), seedling dry weight (2.7–36.5%), and seedling vigour index I (20.1–52.5%) and II (12.3–53.7%), whereas an increase in electrical conductivity (EC) (18.7–38.9%) were observed in discoloured seeds compared to healthy seeds. Similarly, the significant decrease in starch (5.3–37.6%) and protein (1.6–46.2%) content was recorded, whereas, an increase in total antioxidant (3.3–37.1%) and total phenol content (0.58–26.03%) was seen in discoloured seeds, as compared to healthy seeds. The results show that the seed quality is highly compromised in discoloured seeds, as compared to healthy seeds and need to be addressed through the development of different management practices.

Keywords

• Seed discolouration
• Paddy
• Seed quality parameters
• Biochemical parameters