Delimitation of local mustard (Brassica juncea) germplasm in Sri Lanka and improvement of their nutritive quality
Mustard (Brassica juncea) has been grown in the Indian subc ontinent for hundreds of years as an oil seed crop, however, in Sri Lanka mustard is grown comparatively to a lesser extent. It is widely used as a condiment and oil is used in Ayurvedic medicines. There are ca. 60 mustard accessions available in Sri Lanka. However, the genetic diversity and the relationships among these mustard accessions are yet to be studied. The objective of this study was to assess the genetic divergence of local genotypes of B. juncea using numerical analyses of agro-morphological characters for delimitation and identification of genetically diverse and agronomically superior accessions. Thirty mustard accessions were selected and thirty five agronomic characters were measured. Data were analyzed using different multivariate statistical procedures; Chuster analyses (CA), Principle Component Analyses (PCA) and Discuriminant Function Analyses (DFA). Theresults of the CA, PCA and DFA indicated that there is a difference in the grouping patterns of mustard accessions. Thus, there is a doubt that whether morphological characters are adequate in delimiting the mustard accessions. Therefore, the study suggests to include other sources of information such as biochemical evidence and molecular markers in characterization of mustard accessions. Local mustard consists of high amounts of unfavorable fatty acids (erucic acid) and low amounts of favorable fatty acids (oleic acid). High levels oferucic acid are associated with undesirable effects on cardiac muscles. Commercial canola (B. napus) varieties are nutritionally desirable for its monounsaturated property. Interspecific hybridization between six Australian commercial spring canola varieties and six local mustard varieties was successful in producing F1 hybrid seeds. Regeneration of F1 plants was achieved by embryo culture technique to overcome post-germination barriers using modified Lichter medium (Lichter 1982). Fatty acid analysis of F1 seeds of all crosses with Gas Chromatography revealed amoderate amount of erucic acid (18-21％) compared to that of B. juncea(44-46％)and B. napus (0.2-0.5％). Oleic acid content in F1 hybrids was improved (33-41％) compared to that of B. juncea (7-9％) and B.napus (43-57％). The study clearly indicated a higher possibility of transferring traits like a high level of oleic acid and a low level of erucic acid fron canola to mustard and produce new mustard lines with an improved the fatty acid profile via interspecific hybridization.
mustard accessions morphology fatty acid profile CA PCA DFA interspecific hybridization Sri Lanka
S.R.Weerakoon M.C.M.Iqbal S.Somaratne P.K.D.Peiris W.S.R.Wimalasuriya
Department of Botany, the Open University, Nawala, Sri Lanka Plant Reproductive Biology Division, Institute of Fundamental Studies, Kandy, Sri Lanka
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
1661-1664
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）