Genotypic and environmental effects on agronomic and nutritional value of Brassica rapa

In Galicia (northwestern Spain), Brassica rapa subsp. rapa L. includes turnip greens and turnip tops as main crops. Evaluation of B. rapa varieties with wide adaptability across diverse farming environments is important for selecting varieties for future breeding programs based on producers and consumers preferences. Twelve varieties of this species were evaluated in seven environments to determine the best performing varieties and to assess their nutritional characteristics. Different agronomical traits related with production, earliness, and adaptation were evaluated and most of them showed significant differences among varieties, years, and locations. To study more deeply the effect of the genotype main effect (G) plus the genotype × environment interaction (GE) on fresh production, the site regression model (SREG) was used. The G+GE interaction explained 46 and 58% of fresh production for turnip greens and tops, respectively. The GGE biplot technique facilitates a visual evaluation of superior genotypes. The varieties MBG-BRS0550 and MBG-BRS0082 were the best genotypes for turnip greens production for almost all environments whereas the most suitable varieties for turnip tops production were MBG-BRS0472 and MBG-BRS0143. Varieties differed significantly for crude fiber and acid detergent fiber (ADF) content and they showed higher concentration of the anions Cl−, NO3 −, and SO4 2– in turnip greens than in turnip tops. Both plant organs showed high contents of Ca, K, Mg, and P. Therefore, B. rapa varieties evaluated proved to be a valuable source of minerals, protein, and fiber.Research supported by the the Xunta de Galicia (PGIDIT06RAG40302PR), the Plan Nacional I+D+I (AGL2009-09922) and the Excma. Diputación Provincial de Pontevedra. Marta Francisco acknowledges an I3P fellowship from the CSIC.Xunta de GaliciaMICINNDiputación Provincial de PontevedraCSICPeer reviewe