Assessment of distinctiveness, uniformity and stability of basmati rice (Oryza sativa L.) varieties based on morphological descriptors

Abstract

Eighteen basmati rice varieties were characterized using morphological descriptors adopted from the DUS guidelines of PPV and FR Authority and subsequently examined for their Distinctiveness, Uniformity and Stability. Among the 46 visually assessed characters 26 characters were monomorphic, 11 characters were dimorphic and seven characters were polymorphic indicating their potential for varietal characterization and distinctiveness. No intra-varietal variation was observed for any of the visual characteristics and expression of characters in different varieties remained same for the two consecutive years confirming the uniformity and stability of the varieties. Combined Over Years Distinctiveness (COY-D) analysis was made on 14 measurable DUS descriptors which revealed distinctiveness for all varieties with respect to each other. COY-D analysis was complemented with MJRA analysis. The slope of the MJRA curves in both the years and regression coefficients indicated that all the considered characters were not completely independent and they are interacting with each other as well as with environment. Combined Over Years Uniformity (COY-U) analysis for five of the measurable characteristics revealed that 15 out of 18 varieties were almost uniform for the characters under study. However the other three varieties were non-uniform for one or two characters emphasizing the need for their further purification to attain a considerable level of homogeneity in their heterogeneous blend. On the basis of grouping characteristics unique morphological profiles could be established for seven varieties. When all the 60 morphological descriptors were studied two more varieties could be distinguished. Thus the morphological DUS descriptors could establish distinctiveness of some varieties but varieties showing overlapping of the expression for these characters could not be discriminated hence some other markers/ descriptors could be considered for complementing the morphological DUS descriptors for establishing the distinctiveness.