COMBINING ABILITY AND HETEROSIS IN Brassica napus L. USING LINE-TESTER METHOD

Abstract

An experiment on oleiferous !Jratcica neynis L. was conducted to evaluate seven female parents (line) and thirteen male parents (testers) in a line x tester design at the research field of Sher-e- Bangla Agricultural University, Dhaka during November 2012 to April 2013 to estimate their heterosis and gene action for ten different characters. Out of 91 of Fis, no cross combinations showed desirable negative heterosis for the characters of shorter plant height and early maturity. NAP-9905 x NAP-2013 showed desirable negative heterosis for early flowering. NAP-9905 x NAP-9904 showed desirable positive heterosis for number of primary branches per plant, NAP- 9905 x NAP-94006 for number of secondary branches per plant and number of siliqua per plant. The hybrids NAP-9908 x NAP-2001 were found to be the best heterosis for siliquae length but NAP-lOS x NAP-I 79 and NAP-108 x NAP-2022 found to be best for seeds per siliqua. For thousand seed weight the hybrids NAP-9908 x NAP-2013 was best. For seed yield per plant the crosses NAP-lOS x NAP-9901 was found to be the best. The parent Nap-248 was the best general combiner for early flowering. The parent NAP-lOS was the best for desirable plant height, seeds per siliqua and yield per plant. The parent BS-13 was the best general combiner for early maturity, while the parent NAP-248 was the best general combiner for 1000 seed weight. The cross NAP-9905 x NAP-9904 was good specific combiner for number of secondary branches and NAP-9905 .x NAP-94006 for number of siliquae per plant. The cross NAP-205 x NAP-9901 was the best specific combiner for plant height. The combination BS-13 x NAP-2022 was the best specific combiner for early flowering and BS-13 x NAP-2066 for seed yield per plant while NAP94006x NAP-248 was the best for early maturity. The hybrid NAP-248 x NAP- 200J was the best for number of primary branches per plant and NAP-205 x NAP-2012 for the number of seeds per siliqua and NAP-9908 x NAP- 130 was best for 1000-seed weight.