With the purpose of going deep into the study of endosperm proteins in high protein content maize inbreds developed at the Institute since 1990, electrophoretic studies were started. A modified version of SDS-Page electrophoresis technique was used to analyze 9 inbreds classified as flint, opaque2 and waxy. The gel was prepared using acrylamide 35% w/v, NN-methylene-bis-acrylamide 2% w/v. Both reagents were adjusted to ph 8.8 (1M Tris pH 8.8) for the running gel and HP 6.8 (1M Tris HP 6.8) for the stacking gel. The molecular weight marker used contained: phosphorolidase b (MW 97,000), carbonic anhydrase (MW 29,000), bovine albumin (MW 66,000) and egg albumin (MW 45,000). Figure 1 shows the electrophoretic pattern of the materials analyzed. Bands 1, 7 and 8 are present in all the genotypes, whilst band 10 only appears in opaque2 maizes. Using NTSYS programme, the affinity degree amongst the genotypes studied was calculated using the protein bands observed in the electrophoretic pattern as the traits to analyze the gel. Figure 2 shows the phenogram obtained according to which the genotypes divide into 2 groups at the similarity level of about 0.20. Group 1 comprises flint and opaque2 inbreds whilst waxy maizes are placed in Group 2. Group 1 also divides at the similarity level 0.30 into two subgroups: one comprises high quality protein maizes (opaque2) and the other embraces normal type maize (flint). The phenogram results agree 100% with the data registered in the genealogical records since 1990.
Figure 1. Electrophoretic patterns for 2 endosperm proteins observed in 9 maize inbreds.
2. Phenogram belonging to 9 maize inbreds analyzed by their endosperm
protein electrophoretic pattern (CCC: 0.725).
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