Abstract:
The experiment was undertaken using 33 promising advanced populations of
Brassica napas L. at the experimental field of Sher-e-Bangla Agricultural University,
Dhaka during November 2019 to February 2020 considering ten yield contributing
characters. To assess advanced populations, the study examined the magnitude of
character variations, heritability, genetic advance, correlation, and direct and indirect
effects of different characters on seed yield per plant. Analysis of variance revealed
significant variations among all populations for all the traits. Minimum difference
between phenotypic and genotypic variance was observed in days to 50% flowering,
number of primary branches per plant, number of secondary branches per plant,
length of siliqua, number of seeds per siliqua, thousand seed weight and seed yield
per plant. However, high genotypic and phenotypic coefficient of variation were
observed in the number of primary branches per plant, number of secondary branches
per plant, number of siliquae per plant, thousand seed weight and seed yield per plant.
In siliqua per plant, high heritability was observed with high genetic advance,
indicating that these traits were under additive gene control and that selection for
genetic improvement would be efficient. Plant height (cm), secondary branches/plant,
siliqua/plant, siliqua length (cm), and thousand seeds weight (g) all showed a positive
significant genotypic and phenotypic correlation with seed yield per plant. The path
coefficient analysis was carried out using the correlation coefficient to determine
direct and indirect influence that was stated that primary branches/plant, secondary
branches/plant, siliqua/plant, and thousand seed weight (g) all had a positive and
direct effect on yield per plant, indicating that they were the most important
contributors to seed yield per plant. Higher seed yield per plant was observed in G20
(9.59 g), G12 (9.19 g), G15 (7.45 g), G22 (7.25 g) and G5 (7.24 g) and selected as
promising population for future hybridization program.
Description:
A Thesis
submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE
IN
GENETICS AND PLANT BREEDING
SEMESTER: JAN-JUNE, 2021