Abstract:
Executive Summary
The project was under taken to characterized the 24 F
2
2
and 24 BC
1
F
breeding populations
for twelve yield, and yield contributing traits at Sher-e-Bangla Agricultural University,
Dhaka during rabi season 2022-2023 in a randomized complete block design (RCBD) with
three replications. Analysis of variance revealed that significant variation was existed among
the F
2
and BC
1
F
1
1
populations. Except days to siliquae maturity, high heritability coupled
with high genetic advance were found in all the traits suggested that selection could be
rewarded for improvement for these traits. The trait association analysis showed that yield
per plant was positively associated with siliquae length, seeds per siliquae, 1000 seed
weight, and harvest index at both genotypic and phenotypic levels. The mean performance
analysis showed that days to siliquae maturity was lowest in the F
population, G24 (84.00
DAS), while the shortest plant height was observed in G6 (83.11 cm), and G1 (88.08 cm).
Both the 1000-seed weight, and yield per plant were highest in G23 (3.73g and 10.33), G16
(3.71 g and 9.79 g), and G14 (3.78 and 8.14 g) among the F
2
2
populations. In days to siliquae
maturity, total 20 F
populations showed the expected negative heterosis over check variety
1 (cv. Maghi), while for plant height a total of 11 populations manifested the highest
negative heterosis over check variety 2 (cv. BARI Sharisha 14). Regarding yield
contributing traits, total 15 F
2
populations manifested the positive heterotic effects over
check variety 1. Again, a total of 8 F
2
populations over check variety 1, and 14 populations
over check variety 2 manifested the expected positive heterotic for yield per plant.
Furthermore, among the backcross (BC
2
1
F
) populations, the lowest days to siliquae maturity
was recorded in G23 (83.00 DAS), while the lowest plant height was observed in G8 (80.78
cm). The highest 1000-seed weight was recorded in the BC
1
1
F
population, G17 (4.51 g), and
the highest seed yield found in G17 (12.33 g) BC
1
F
1
1
population. Over all, the F
populations
viz., G2, G5, G6, G9, G10, G14, and G24 have been selected for developing early, and short
stature lines, while G2, G9, G14, G16, G22, G23 and G24 populations have been selected to
develop high yielding lines. Again, the backcross the BC
1
F
populations viz., G1, G6, G8,
G12, G14 G16, G17, G19, G20, G21, G23, and G24 populations have been selected for
developing early maturing and yield potential breeding lines of B. rapa.
