The nabicol: a horticultural crop in northwestern Spain

Abstract

Nabicol (B. napus L. var. pabularia) is a traditional crop in the Northwest of Iberian Peninsula (South of Galicia and North of Portugal) where it is grown during the winter season on small farms and gardens using traditional varieties. A collection of 36 populations of nabicol from Galicia (northwestern Spain) was evaluated during 2002 and 2003 in two locations and two growing seasons (spring/summer and autumn/spring) for 28 agronomic and morphological traits. The objectives of this study were to: (i) evaluate a collection of nabicol landraces from northwestern Spain, (ii) determine the suitability of this germplasm as a summer crop and (iii) study the genetic diversity among local populations. Significant differences were observed among populations for most traits. Genotype × environment interaction was significant for most of them. Spring/summer growing season could be recommended for growing nabicol but resistance to Lepidoptera pests attacking Brassica crops should be improved. Most populations had an agronomic value similar to the commercial variety. The most promising variety for horticultural use was MBG-BRS0063, which showed the highest yield. Morphological and agronomic data were subjected to cluster analysis and four groups were defined with a group clustering most populations. The low genetic diversity could be explained because populations were collected in close geographical areas and the selection made by farmers was always for a horticultural use. These results give information about the diversity and breeding value of the nabicol Spanish germplasm, which could be useful in breeding programs