A rapid and economical method for hybrid purity testing of tomato (Lycopersicon esculentum L.) F1 hybrids using ultrathin-layer isoelectric focusing of alcohol dehydrogenase variants from seeds.
In the cultivated tomato (Lycopersicon esculentum L.), two electrophoretic variants of the enzyme alcohol dehydrogenase (ADH) encoded by the alleles Adh-1+ and Adh-1(1) are found. A rapid and economic method for testing the hybrid purity of tomato F1 seeds, based on the expected presence of Adh-1 alleles, was developed. The method is based on the analysis of the ADH variants by ultrathin-layer isoelectric focusing, pH range 3-10, of crude extracts from imbibed seeds, followed by enzyme activity staining. The isoelectric points (pI's) of the ADH variants were estimated to be 5.5 and 5.7 for Adh-1+ and Adh-1(1), respectively. Using the procedure described and a newly developed sample applicator strip, it is possible for one person to routinely analyze 1152 seeds per day using only a single electrophoresis unit. An investigation of a large number of inbred lines, both experimental and commercial hybrids, together with open-pollinated varieties, showed the potential of the method. Among F1 hybrids, a higher frequency of the Adh-1(1) allele was found than among open pollinated varieties, suggesting that F1 hybrid breeding has resulted in a higher frequency of Adh-1(1) alleles by selection of linked genes.
van den Berg
B M
BM
Royal Sluis, Research and Development Department, Enkhuizen, The Netherlands.
D000426:Alcohol Dehydrogenase / Q000235:genetics*; D001947:Breeding; D003362:Cost-Benefit Analysis; D005787:Gene Frequency; D008040:Genetic Linkage; D014644:Genetic Variation; D006822:Hybrid Cells / Q000737:chemistry; D007525:Isoelectric Focusing / Q000191:economics; D010641:Phenotype; D010944:Plants / Q000235:genetics*; D012639:Seeds / Q000235:genetics*
D000426:Alcohol Dehydrogenase