ความแตกต่างระหว่างพันธุ์ข้าวก่ำในการตอบสนองต่อการพรางแสงใน ผลผลิต ปริมาณแอนโทไซยานินและการแสดงออกของยีน

Abstract

Purple rice (Oryza sativa L.) contains anthocyanin, which acts as an antioxidant and functional food for human dietary. Levels of anthocyanins, growth and production in rice are mainly controlled by the availability of light. However, the shade could affect the anthocyanin biosynthesis genes. Therefore, the objective of this study was to assess the influences of shading stress related to anthocyanin content, yield and the expression of OsDFR gene. This research was conducted using the split-plot in a completely randomized design with four levels of shading by using a black net, which has the ability to reduce light intensity in three replications: no shading, 30%, 50% and 70% shading as main plots and the purple rice varieties as subplots: KJ CMU-107, K2, K4, and KDK10 during anthesis to maturity. Shading significantly decreased yield and yield components. In addition, the shading effects on anthocyanins content in purple leaf rice and straw varieties, K4 and KDK10, were significantly increased. However, anthocyanin content was not detected in the green leaf rice varieties, KJ CMU-107 and K2, whereas seed anthocyanin was found in all rice varieties. The anthocyanins content in seeds showed the highest content at the when 50% shading and decreased at the shading of 70%. The chlorophyll contents statistically significant increased with the increasing of the shading levels in all rice varieties. However, the OsDFR gene expression levels were different by shading levels in four rice varieties. The OsDFR gene illustrated the highest expression at the shading levels of 30% for K4, and at the shading levels of 50% for KDK10 while the expression of OsDFR gene was not detected in the purple rice varieties with the green leaf (KJ CMU-107 and K2). Taken together, the results suggested that some purple rice varieties were more suitable for planting under low light intensity based on lower level of grain yield loss, strong shade tolerance and high anthocyanin content in leaf and grain pericarp. However, it is necessary to explore the effects of light intensity on genes and the intermediates in the anthocyanin synthesis pathway for further study.