Abstract:
An experiment was carried out with 39 F
2
populations of Brassica rapa L. at the
experimental field of Sher-e-Bangla Agricultural University, Dhaka during November
2019 to February 2020 considering thirteen yield contributing characters. To study 39
F
2
populations, the magnitude of variations in the characters, correlation, heritability,
genetic advance, direct and indirect effect of different characters on seed yield per
plant were taken under analysis. Significant variation was observed among all
populations for all the characters. For all of the traits, the phenotypic variance was
higher than the genotypic variation. Number of secondary branches per plant, total
siliqua and yield per plant showed high genotypic and phenotypic coefficient of
variance. Days to first flowering, days to 50% flowering and days to 80% flowering
showed high heritability coupled with low genetic advance and low genetic advance
in percentage of mean. Study on correlation revealed that yield/plant had significant
and positive association with number of primary branches per plant; number of
secondary branches/plant and total siliqua but non-significant and negative
association with days to first flowering and yield per plant at both phenotypic and
genotypic level. Path co-efficient analysis revealed that number of seeds per siliqua
showed highest positive direct effect on yield/plant followed by days to maturity, days
to 80% flowering, plant height, total siliqua and siliqua length. On the other hand,
number of primary branches/plant, number of secondary branches/plant, days to 50%
flowering, root length and thousand seed weight had negat ive direct effect on yield
per plant. Selection was conducted among 39 F
2
populations of Brassica rapa L. to
find out the early maturing and the highest yielding populations. 12
populations such
as
P5XP1, P5XP3, P1XP2, P1XP7, P6XP5, P7XP3, P3XP5, P3XP1, P3XP4, P4XP2,
P5XP2, and P5XP7
were selected for high yielding and early maturing from the 39
populations for further trial.
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
