Ak. Pradhan et al., HETEROSIS BREEDING IN INDIAN MUSTARD (BRASSICA-JUNCEA L CZERN AND COSS) - ANALYSIS OF COMPONENT CHARACTERS CONTRIBUTING TO HETEROSIS FOR YIELD, Euphytica, 69(3), 1993, pp. 219-229
Divergence of 25 accessions of Brassica juncea of Indian, CIS (Commonw
ealth of Independent States, former USSR) and synthetic origin was stu
died by D2 analysis. On the basis of divergence, ten accessions were s
elected and crossed in a diallel fashion without reciprocals to study
the combining ability and heterosis. None of the accessions was found
to be a good general combiner for all the nine quantitative characters
that were studied. Significant heterosis over better parent for singl
e plant yield was recorded in CIS x Indian and synthetic x CIS crosses
(5 each) followed by Indian x synthetic types (3). The analysis of co
mponent characters showed that the mean performance of the majority of
hybrids was intermediate for five out of six yield attributing traits
, thus exhibiting dominance or partial dominance effect. To estimate t
he contribution of such yield attributing traits towards heterosis for
yield, a comparison was made among three parameters viz. heterosis ov
er mid parent (MP), better parent (BP) and better yielding parent (BYP
) of the concerned hybrid. It was observed that estimation of heterosi
s from BYP was a more accurate method to determine the contribution of
component characters towards yield heterosis than the analysis based
on MP and BP. From the component character analysis, it was concluded
that characters like number of primary and secondary branches, number
of siliqua per plant and siliqua density contributed significantly tow
ards heterosis in yield. Plot level yield trials of two selected hybri
ds (Skorospicka II x RH30 and Donskaja IV x Varuna) over two growing s
easons revealed 29.4 to 91.8% heterosis over BYR.