Unraveling the morpho-biochemical differences between purple rice and green rice

Abstract

Recently in Bangladesh, farmers in some areas such as Cumilla, Gaibandha districts are started to grow purple-leaved rice. Very little information is available about Purple rice. This plant contains high anthocyanin in its leaves and thus it has a strong antioxidant defense system. Therefore, we aimed to dissect the differences between Purple rice and BRRI dhan28. To do this, we grew Purple rice and BRRI dhan28 under normal conditions. We measured the morphological and biochemical parameters of both rice varieties. We also measured plant height, length of flag leaf, the width of flag leaf and Tiller number/hill at 20, 30, 40 days after transplanting (DAT). The results showed that plant height of Purple rice and BRRI dhan28 were similar and there were no differences between them at 20, 30, 40 days after transplanting. At 20, 30 and 40 DAT there was no significant difference between Purple rice and BRRI dhna28 in plant height and length of the flag leaf. The width of the flag leaf of Purple rice and BRRI dhan28 was statistically similar at 20 and 30 DAT but significantly different at 40 DAT. The tiller number/hill of BRRI dhan28 was significantly higher than Purple rice at 30 and 40 DAT but similar at 20 DAT. We also measured biochemical parameters such as pigment content (Anthocyanin, chlorophyll a, chlorophyll b, total chlorophyll and total carotenoid contents), osmoprotectant content i.e. proline content and activity of antioxidant enzyme i.e. catalase activity. The amount of anthocyanin, proline content and catalase activity was significantly higher in Purple rice than BRRI dhan28. Total chlorophyll content of Purple rice was significantly higher in Purple rice than that of BRRI dhan28 but there was no significant difference between them in total carotenoid content. It can be concluded that Purple rice is superior to BRRI dhan28 in terms of more chlorophyll, anthocyanin and proline contents as well as catalase activity.