The genetic evaluation of 130 oilseed rape (Brassica napus L.) cultivars using SSR (single sequence repeat) markers

Oilseed rape (Brassica napus) has become one of the most cultivated oil crop, due to its utilization in different ways as human nutrition, as alternative biofuel source or raw material for the chemical industry. Also the residues obtained after the oil extraction are used in the animal feeding being considered important protein sources (Snowdon et al., 2007).The aim of this study was to make the genetic evaluation of 130 oilseed rape cultivars provided by Center for Genetic Resources Nederland using SSR markers. For this, we used 51 SSR markers which amplified 139 specific fragments. Based on a obtained data it was calculated the genetic similarity (GS) between analyzed genotypes that concluded in one matrices which led to the generation of the SSR dendrogram. Analyzing the obtained dendrogram it was observed that a high genetic diversity between the studied cultivars

SSR markers associated with the resistance of rapeseed to the attack of Sclerotinia sclerotiorum (Lib.) de Bary

Sclerotinia sclerotiorum (Lib.) de Bary is one of the most important pathogens of the rapeseed crop worldwide. Depending of the environmental conditions, the yield losses can get up to 100%. Until now, no oilseed rape cultivars are marked as having resistance to this pathogen. Genetic resistance is considered to be the most efficient way of protecting the plants from this patthogen. The aim of this study was to identify SSR markers for white rot resistance in a collection of 130 rapeseed cultivars, from the Centre for Genetic Resource of Netherlands. There were made correlations between the genotypic and the phenotypic data obtained for the artificial infection with the pathogen and there were revealed 5 SSRs significantly associated with rapeseed resistance to white rot. The artificial infection was made on detached leaves, in controlled environmental conditions. The fungus was grown on solid medium PDA. There were put 2 plug discs of PDA medium with mycelia near the main vein of the leaves. On the control leaf there were put 2 discs of PDA medium, without mycelia. The diameter of the lesions was measured 72 h after inoculation, with a linear ruler. For the genetic analysis, there were used 51 SSR markers, that amplified 139 polymorphic fragments. The fragments ranged between 80 and 340 bp. In order to correlate the data, we used the ANOVA method, in the SPSS v.13 software. The identification of these SSRs will enhance the breeding for white mold resistance in Brassica napus L

Identification of some molecular markers associated with resistance of some oilseed rape cultivars (Brassica napus L.) at the pathogen Verticillium longisporum

Oilseed rape (Brassica napus L) is a relative young species which appeared a few hundred years ago through a spontaneous interspecific hybridization between cabbage (Brassica oleracea L.) and turnip rape (Brassica rapa L.) (Rygulla et.al., 2007). Among the main diseases that can affect the oilseed rape culture we can find also verticillium wilt caused by the pathogen Verticillium longisporum. The mycelium is colonizing the vascular system of the plant and cause his obstruction, so due to the water stress the plant can die. Because, until now there are no available approved chemicals to prevent this disease, the phytosanitary control of this disease can be realized by cultivating some resistant varieties. The aim of this study was utilization of the SSR markers to identify some resistance sources of oilseed rape to Verticillium longisporum pathogen attack. For this purpose we used a number of 130 oilseed rape cultivars which were artificially infected with the pathogen V. longisporum. For the molecular studies, we used 51 SSR markers which amplified a number of 139 specific fragments. Correlating the molecular data obtained after the SSR analysis and the phenotypic data obtained after the artificial infection, we identified 18 SSR markers associated with resistance to V. longisporum. This results are very important for the next studies regarding the breeding of oilseed rape, for the identification of the resistance genes to V. longisporum