Origin, Importance, Establishment, Future Aspects and Strategies of Brassica napus L.

Brassica napus L. is very important oilseed crop in the world. It is the second largest world oil crop after soybean with 13% world production. Its use has been documented in Europe since the 13 century and th has been grown 2000 BC in India mainly for its use as oil for lamps. B. napus L. is thought to have originated in either the Mediterranean regions or Northern Europe. It has been developed about 7500 years ago from two diploid species; B. rapa and B. oleracea containing C and A genomes, respectively, which was later confirmed by artificial synthesis of amphidiploids and chromosome pairing, use of genome specific chromosome markers, nuclear DNA content, DNA analysis and chloroplast data. A large number of rearrangements (translocations and inversions) have been found in two diploid genomes indicating that they have formed prior to the divergence of the two species. The linkages also consist of central fusion or fission which shows that this mechanism has played an important role in the evolution of B. napus L. Due to high linkage disequilibrium by diagnostic markers in the genomes can be used for marker assisted breeding for producing low glucosinolates and erucic acid in its seed. Narrow genetic base of resynthesized B. napus L. can increase the genetic variation for establishing a distant gene pool for production of hybrids and adaptation of breeding material selection in oilseed B. napus L. has accelerated the loss of erucic acid and glucosinolates and preserving the oil synthesis genes. These practices provide the basis for amphidiploid evolution and its association with crop domestication and improvement. The genus Brassica includes a number of important B. carinata Burn. (Abyssinian or Ethiopian mustard), crop species (about 37) which produce edible roots B. juncea Czern. (Indian mustard) and Coss. and B. nigra (Raphanus spp.), buds, stems and flowers and seeds (47). L. (28). The wild relatives are useful for the source of The Brassicaceae (also known as Crucifera or mustard) cytoplasmic male sterility for the hybrid seed production is a large dicot family (47) and is a major contributor to the in the Brassica and also share nuclear genes which can be human nutrition of millions of people worldwide (43). incorporated for resistance against different pests and The species belonging to Brassica are economically diseases. important species which include; B. oleracea (n=9), Among all the Brassicas, the B. napus L. (also called B. rapa (n=10) also called as B. compestris, B. nigra (n=8), rapeseed, oilseed rape and canola) is the most B. juncea (n=18), derived from the interspecific crossing economically important species, an amphidiploid between B. nigra (n=8) and B.rapa (n=10), B. carinata containing the two genomes of its progenitors B. rapa (n=17), derived from the interspecific crossing between (A genome) and B. oleracea (C genome). It exists in B. nigra and B. oleracea and B. napus (n=17), derived different forms such as oilseed, vegetables, rutabagas and from the interspecific crossing between B. rapa and fodder (45). It is the second largest world oilseed crop B. oleracea (21). B. napus L. and B. compastris after soybean with 13% of world production (45). Its seed rapeseed and canola oil (27). The mustard group includes