Abstract:
The Rice Research and Development Institute (RRDI) of Sri Lanka has developed five
exportable rice cultivars; At 362, Bg 94-1, Bg 360, Bg 1165-2, and Bw-Bs-1-2-31.The
present study was conducted to establish the identities of these five cultivars at
caryopsis level in comparison compared to those of mega rice cultivars (Bg 352, Bg
300, Bg 358, Bg 359, Bg 357, Bg 379-2, and At 353) in Sri Lanka using DNA
fingerprinting and sequencing. These rice cultivars were grown in a greenhouse and
a field using breeder-seeds. The seeds were harvested and subjected to a
morphometric analysis using decision tree algorithms based on the size and colour of
seeds and caryopses. The algorithms estimated the percentage accuracy of detection
based on morphometric analysis ranged from 3.13-84.38 %. Similar seed and
caryopsis combinations were grouped and exposed them to a panel of human subjects
to discriminate the samples in each combination and subjected the data to calculate
Kappa (K) and inter-rater reliability (IRR) statistics. The K was always 0.00, and IRR
was 27% implying the inability of accurate visual differentiation. In the DNA
fingerprinting analysis, a set of six SSR markers (RM206, RM246, RM251, RM335,
RM475, and RM23744) were selected that can establish the cultivar identity. In
addition, the combined analysis of DNA sequencing of 12 cultivars with three selected
loci, (Seq 7-8, HvSSR12-34 and RM23744) authenticated the varietal identities.
