Abstract:
Breeding rice varieties for high yield along with resistant to abiotic and biotic stresses and accepted
grain quality parameters are timely needed. Genetic diversity is important for the success of any plant
breeding programme. Morphological characters have been used to assess the genetic variation
among the population of rice. The present study aimed to study the genetic diversity and variability
of selected rice varieties at the Regional Rice Research and Development Centre, Bombuwala (6° 57’
0” N, 80° 0’ 0” E), Sri Lanka during the Yala 2022 season. Eighteen rice varieties were selected for the
experiment including exotic and local varieties. Data were collected from three replicates, five
randomly taken plants per each replicate. Plant height (cm), culm length (cm), panicle length (cm),
numbers of productive tillers per plant, numbers of filled grains per panicle, numbers of unfilled
grains per panicle, grain yield per panicle (g), grain yield per plant (g), hundred seed weight (g), grain
length (mm), grain width (mm), grain breadth, kernel length (mm), kernel width (mm), kernel
breadth were recorded according to standard evaluation system, 2014. After Hierarchical clustering,
K mean cluster analysis was followed for meaningful clustering and it revealed two major clusters.
Cluster one was consisted with Bw 367, Bw 374, At 362, At 307 and IRLON 07A-107 while cluster
two was consisted with New Basmathi, Red Basmathi, Pusa Sugand, Jasmin Rice, IRLON 121(2018),
IRLON 122 (2018), IRLON 221 (2018), IR 81866 33-3-1 (BLB 81), IRFAON 421, IRFAON 417, Pusa
Basmathi, Basmathi 370, Basmathi 442. Some characteristics contribute more to obtain high
diversity at least significant at P>0.05. Main anticipation of general cultivation is high yield.
Therefore, cluster one has ideal morphological traits could be used in general cultivation as showing
higher values of yield components’ traits as higher numbers of filled grains per panicle, highest grain
yield per panicle and highest grain yield per plant. In addition, it can be used as parents for breeding
high yielding varieties. Varieties in cluster two has international market accepting grain size and that
can be used to incorporate more advantageous characters lacking in varieties in cluster one.
