Abstract:
Eight genotypes of Onion (Allium cepa L.) were evaluated to find out the genotypes for
drought tolerance using morpho-physiological and yield contrasting indices at Sher-eBangla
Agricultural
University,
Dhaka
during
July,
2021
to
June,
2022.
The
experiment
was
laid out in Complete Randomized Design (CRD) with three replications. Mean
performance, genetic parameters, Pearson’s correlation coefficient, and principal
component biplot analysis on different yield contributing characters and yield of onion
genotypes were estimated. The longest plant (49.43 cm) was recorded in the genotype
Lal Teer King, while the shortest plant (20.287 cm) was found in onion genotype BARI
Piaj 3. The highest bulb yield/plant (34.50 g) was recorded in the genotype of Lal Teer
King, whereas the lowest bulb yield/plant (21.38 g) from the genotype of BARI Piaj 3.
Phenotypic coefficient of variation was higher than the genotypic coefficient of
variation for all the yield contributing traits indicating drought stress influenced the
genotypes. In Pearson’s correlation study, yield per bulb positively and significantly
correlated with plant height (0.818), root length (0.511), no. of leaves (0.744), leaf
length (0.720), leaf breadth (0.756), bulb length (0.469), bulb diameter (0.716), leaf
area (0.893), chlorophyll content (0.886) and dry weight per bulb (0.854). The positive
and significant correlation observed between grain yield and traits under-drought stress
conditions provided evidence that studied traits might ultimately be considered as a tool
for effective selection of drought tolerant genotypes. Path coefficient analysis revealed
to that plant height had direct positive effect (5.058), root length had direct positive
effect (0.263), no. of leaves had direct positive effect (1.129) and dry weight per bulb
had direct positive effect (0.44) on yield per bulb, indicating these were the main
contributors to yield per bulb. The study selected 8 genotypes with high grain yields
under drought stressed conditions and favorable adaptive traits useful for breeding. In
consideration of yield contributing characters and yield Lal Teer King performed better
under drought condition followed by BARI Piaj 1, BARI Piaj 2, BARI Piaj 3,
Taherpuri, Faridpuri, Bombay and Annex N-53.
