Genetic variability of carrot seed proteins analyzed by one‐ and two‐dimensional electrophoresis with immobilized pH gradients

The genetic variability of eight carrot populations representing commercially important morphological types was analyzed for seed protein polymorphism by one‐ and two‐dimensional electrophoresis using immobilized pH gradients (IPG) in order to assess the potential of both techniques in carrot hybrid breeding as well as genetic quality testing of carrot trade seeds. The digitized silverstained one‐ and two‐dimensional gels of the urea/detergent‐soluble seed proteins were subjected to computer analysis to estimate both the inter‐ and intrapopulation genetic variability. The results indicated that isoelectric focusing (IEF‐IPG) of seed proteins is a powerful tool for quick screening of the genetic variability present between and within carrot populations, while two‐dimensional polyacrylamide gel electrophoresis (IPG‐DALT) can be employed to establish detailed genetic relationships of carrot populations selected by initial IEF‐IPG screening in order to use genetic distant and homogeneous populations for successful carrot hybrid breeding. However, the applicability of IEF‐IPG in genetic quality testing of carrot seeds seems to be restricted to hybrid purity testing. IPG‐DALT is a far more powerful tool to profile unambiguously all carrot varieties commercially used in order to test the genetic quality of trade seeds, because this technique exhibits protein spots or spot combinations exclusively found in each of the eight varieties investigated.