| dc.description.abstract | This field research work offers an account of the generating blast resistant fine aromatic rice
over June to December 2016 in Dinajpur using landraces viz., BRRI dhan 34 as susceptible,
Zotakatari and Kalijira as resistant cultivars following Randomized Complete Block Design
with three replications. Data were assessed on plant height (cm), number of leaves in mother
tiller, length of leaf blade and sheath (cm), number of effective tillers, panicle length (cm),
spikelet per panicle, number of spots, length and width of the largest spot (mm), percent leaf
blast severity, number of death leaf, yield (g) and 1000-grain weight (g) where data were
collected at 25 DAT, 45 DAT and 65 DAT. The results indicated that BRRI dhan 34
received the highest number of tillers per plant 19.07, 28.20 and 29.20, length of leaf blade
52.10 cm, 56.97 cm and 60.80 cm, number of spots per plant 84.1, 89.8, and 94.47, number
of death leaf per plant 3.60, 5.06 and 6.20 at 25, 45 and 65 DAT, respectively. BRRI dhan 34
also showed the highest number of effective tillers per plant 23.93, panicle length 25.2 cm,
number of spikelet per panicle 153.3, 1000-grain weight 27.52g and yield per plant 3.251g.
The mean squares of the three cultivars exhibited strong and significant differences for most
of the characters including number of tillers per plant, number of leaves in mother tiller,
length of leaf sheath and blade (cm), plant height (cm), panicle length (cm), spikelet per
panicle, number of spots per plant, 1000- grain weight (g) and yield per plant (g). The
genotypic variance (Vg), phenotypic variance (Vp), genotypic coefficient of variation (GCV),
phenotypic coefficient of variation (PCV), heritability, genetic advance (GA) and genetic
advance (GA%) were estimated where the PCV values were higher than corresponding GCV
values for number of tillers per plant, number of leaves in mother tiller, length of leaf sheath
and blade, plant height, number of spots per plant, length and width of the largest spot, and
number of death leaf per plant. Very high phenotypic and genotypic coefficients of variation
were found in number of spots per plant. In comparison with others, the number of tillers per
plant (99.62), length of leaf sheath (99.89), plant height (99.92), number of spots per plant
(99.95) and number of death leaf per plant (99.08) showed high heritability. Number of
tillers per plant showed significant and positive correlation with length of leaf blade
(r=0.426***), plant height (r=0.230*), number of death leaf per plant (r=0.303**), number
of spots per plant (r=0.740***), width of the largest spot (r=0.306**), spikelet per panicle
(r=0.544***), yield (r=0.559***), panicle length (r=0.411***), 1000-grain weight
(r=0.564***) and number of effective tillers per plant (r=0.257*). Plant height exhibited
highly significant positive relation with number of spots per plant (r=0.138*), width of the
largest spot (r=0.313**). Number of spots per plant exhibited highly positive significant
correlation with width of the largest spot (r=0.31199**), panicle length (r=0.328**) and
yield per plant (r=0.619***). Spikelet per panicle showed highly significant positive
correlation with yield per plant (r=0.710***), panicle length (r=0.462***), 1000-grain
weight (r=0.436***) and number of effective tillers per plant (r=0.178*). The direct and
indirect effects were partitioned among the nine phenotypic characters as well as among the
disease parameters. Among the phenotypic characters, the highest positive direct effect was
revealed on spikelet per panicle (0.554) on yield followed by number of effective tillers per
plant (0.16) on yield. Spikelet per panicle also revealed higher positive indirect effect via
number of tillers per plant (0.299), panicle length (0.255) and 1000- grain weight (0.243) on
yield. Among the disease parameters percent leaf blast severity showed positive direct effect
(0.369) on yield. Again percent leaf blast severity revealed highest indirect effect on yield
via number of spots per plant (0.251). In crossing, the number of unsuccessful pollinated
panicle was higher (95%) than the number of successful pollinated panicle (5%). The
message come out from the study suggesting the best route in breeding program for
developing disease resistant fine aromatic rice where the number of spots exhibited highly
transmissible character resulting highly significant correlation coefficients with genetically
effective in yield contributing linkage. | en_US |
