Evaluation of Agronomical Traits and Aroma in Tepi Boro Rice Landraces of Bangladesh

Abstract

Twenty-five duplicate or similar named TepiBoro group of rice landraces were studied to evaluate variations through15 quantitative Agronomical traits and aroma using sensory test and SSR markers at Bangladesh Rice Research Institute during Boro 2020-21 season. The sensory test of leaf aroma by using 1.7% KOH solution and molecular characterization using high aroma trait linked SSR markers as RM282 (for QTL aro3.1), RM273 (for QTL aro4) and RM223 (for QTL aro8.1 represented by badh2 gene) were performed. The highest leaf area (39.6 cm2) was observed in Tepu IRRI (Acc. no.6213). The growth duration ranged from 128 to 176 days. TepuDhan (acc. 7986) had the highest number of filled grains per panicle (253). The longest grain (10.26 mm) was found in TopaBoro (acc. 4981) and the highest dehulled LB ration (3.82) was recorded in TopaBoro (acc. 4981). The highest grain yield (930.2 g/plot) was observed in Tepa IRRI (acc. 7855). Besides, the combined result of the sensory test revealed that all the evaluators found leaf aroma in TepiBoro (Acc. 4526), TepuDhan (Acc. 7931) and TopaBoro (Acc. 4373). For PCA, the studied TepiBoro genotypes were grouped into five clusters, where the inter-cluster D2 values ranged from 11.77 to 43.13. The genotypes under clusters V may be selected for crossing with the genotypes of cluster I and cluster IV for developing improved TepiBoro rice variety. All the three aroma linked SSR markers showed polymorphism and RM223 had the highest PIC value and was considered to be the best marker for studying TepiBoro rice germplasm. Topa Boro (Acc. 4373), Tepi Boro (Acc. 4526) and Tepu Dhan (Acc. 7931) showed aroma for SSR primers RM223, RM273 and RM282. The unrooted neighbour-joining tree revealed that the genotypes were grouped into three major clusters. Finally, this study would be useful for breeders to choose and identify the potential pre-breeding materials for developing aromatic TepiBoro rice variety. Moreover, the candidate genes for rice grain aroma could be identified by combining QTL mapping and transcriptome profiling approaches.