APPLICATION OF DNA MARKERS FOR THE DETECTION OF AMYLOSE CONTENT IN SRI LANKAN RICE (ORYZA SATIVA L.) VARIETIES

Abstract

Grain quality improvement of rice is considered as prioritized research area in rice breeding programs in Sri Lanka. Amylose Content (AC) is a key determinant of end quality of rice. Amylose Content is controlled by granule bound starch synthase (GBSS) enzyme which is encoded by waxy gene, located on chromosome 6. Similarly another character associated with grain quality, Gelatinization Temperature (GT), is controlled by the alkali degeneration locus (alk), which encodes for a soluble enzyme called starch synthase IIa (SSIIa). Two SSR markers RM 190 and RM 314 were selected from the previously developed QTL maps that showed association with AC and GT. This study demonstrates the feasibility of RM 190 and RM 314 for the detection of polymorphism associated with AC and GT. In total, 18 different rice varieties were analysed. The relationship between marker genotype and amylose content was detected by comparing the pooled AC under 2 different allele categories using Mann-Whitney Test. The results indicated that RM 190 was able to detect genetic variation among the rice varieties quite efficiently, on the basis of which, the rice varieties could be identified with two categories; with low AC and with intermediate and high AC. Therefore, the SSR marker, RM 190, could be efficiently employed in large-scale screening programmes to predict AC through Marker Assisted Selection (MAS).