Plants of the genus Brassica comprise a remarkably diverse group of crops and
encompass varieties that are grown as oilseeds, vegetables, condiment
mustards and forages. One of the basic requirements for developing hybrid
varieties in oilseed Brassica is the availability of proven heterosis. The
development of hybrid cultivars has been successful in many Brassica spp.
Midparent heterosis and high-parent heterosis (heterobeltiosis) have
extensively been explored and utilized for boosting various quantity and
quality traits in rapeseed. Heterosis is commercially exploited in rapeseed
and its potential use has been demonstrated in turnip rape (B. rapa L.) and
Indian mustard (B. juncea L.) for seed yield and most of the agronomic
traits. The oilseed rape plant, B. napus, possesses two endogenous male
sterile cytoplasms, nap and pol. Ogura type of cytoplasmic male sterility was
first discovered in Japanese wild radish and other male-sterile Brassicas
(Ogura bearing cytoplasm) derived from interspecific crosses. Information
concerning the allelic frequencies of restorers can be useful in trying to
understand their evolutionary origins. The ogu, pol and nap cytoplasms of B.
napus induce sterility in all, some, and only a few cultivars, respectively.
In this study, different kinds of male sterility, combining ability and
heterosis of qualitative and quantitative traits in different Brassica
species will be revi?wed.
Studies on combining ability and heterosis using cytoplasmic male sterility system in Indian mustard [Brassica juncea (L.) Czern & Coss.]