Abstract:
A research was conducted by using twenty six (26) F.1 populations of some inter-varietal crosses
of Brassica rapa and grown in the experimental farm of Sher-e-Bangla Agricultural University.
Dhaka, during November 2009 - March 2010 to study the magnitude of variations in characters,
heritability, genetic advance, character associations, direct and indirect effect of different
characters on seed yield. There were significant variations in number of primary branches per
plant, number of secondary branches per plant, number of silliqua per plant, days to 50%
flowering, length of siliqua, number of seeds per siliqua, 1000 seed weight and yield per plant
showed least difference between genotypic and phenotypic variances. Plant height, length of
siliqua, number of silliqua per plant, days to 50% flowering showed low genotypic and
phenotypic coefficient of variation. Plant height, number of primary branches per plant, number
of secondary branches per plant and number of silliqua per plant showed high heritability
coupled with high genetic advance and very high genetic advance in percentage of mean.
However, length of siliqua showed low heritability. Correlation study revealed that yield per
plant had significant positive association with plant height. number of primary branches per
plant, number of siliqua per plant, seeds per siliqua. and siliqua length (genotypic or phenotypic
level). Path co-efficient analysis revealed that plant height, number of primary branches per
plant, number of siliqua per plant, seeds per siliqua, and siliqua length had the positive direct
effect on yield per plant and days to 50% flowering, number of secondary branches per plant,
and thousand seed weight had the negative direct effect on yield per plant. Based on the
variability study, some F4 plants showing high heritability for short duration and yield
contributing characters were selected from some of cross combinations of the intervarital crosses
of Brassica rapa for further selection.
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: JANUARY- JUNE, 2010
