Assessment of Marker-trait Associations for Amylose Content, Gelatinization Temperature and Yield in Sri Lankan Rice Varieties

Abstract

Rice provides a balanced diet, and regular rice consumption helps maintain a healthy life and prevents many common illnesses. Amylose content and gelatinization temperature are considered major physicochemical factors which significantly affect the nutrition and cooking quality of rice. The Waxy (Wx) gene controls the synthesis of amylose in the endosperm and the ALK gene controls the gelatinization temperature of rice. Both genes are present on chromosome 6. Improving the rice traits is crucially essential to the cultivators and the consumers to overcome the increasing demand for high-quality and nutritionally rich rice. Many studies have been successfully conducted to improve the agronomical traits of rice. However, the concern for improving nutrition and cooking quality-related traits of rice is less common among the breeders. Therefore, considering the current trends, introducing consumer-friendly novel varieties that can fulfill the nutritional requirements is essential to face the increasing domestic demand for high-quality rice. In the present study, we used frequently grown 54 local rice varieties and carried out a markerbased genetic analysis for three traits: amylose content, gelatinization temperature, and yield. Then statistical analysis was carried out using quantitative data of different agronomical and physicochemical traits to identify the correlation and potential to improve such essential traits. The level of amylose content is significantly associated with the gelatinization temperature indicating that AC and GT have a positive correlation. The DNA markers SSIIa and Seq1-2 markers showed monomorphic patterns indicating the narrow genetic basis of the rice varieties tested. This study revealed that existing high-yielding rice varieties could be successfully employed to increase the amylose content while decreasing the level of gelatinization temperature through breeding strategies to make nutritionally rich consumer-friendly novel varieties