INHERITANCE AND IMPROVEMENT OF PROTEIN QUALITY AND CONTENT IN MAIZE; FINAL REPORT

THE TASK OF OBTAINING OPAQUE-2 OR OTHER GENES WITH SIMILAR EFFECTS ON QUALITY OF PROTEIN WITH YIELDS EQUALS TO "NORMAL" HAS PROVEN MORE DIFFICULT THAN ORIGINALLY ENVISIONED. THE OPAQUE-2 GENOTYPE STILL HAS THE DRAWBACK OF LOWER AGRONOMIC YIELD. SCREENING OF MORE THAN 55 COLLECTIONS OF MAIZE FROM THE CIMMYT WORLD GERMPLASM BANK WITH THE NINHYDRIN TEST, AND SCREENING OF GERMPLASM FOLLOWING SEED AND POLLEN TREATMENT WITH CHEMICAL MUTAGENS HAVE RESULTED IN THE ISOLATION OF SEVERAL ENDOSPERM MUTANTS WITH OPAQUE PHENOTYPE AND/OR ALTERATION IN PROTEIN QUALITY. HOWEVER, NONE OF THE MUTANTS ISOLATED THUS FAR HAVE PROVEN TO BE A VIABLE ALTERNATIVE TO OPAQUE-2. GERMPLASM CONTAINING OPAQUE-2 IN SEVERAL DIFFERENT BACKGROUNDS AND A NUMBER OF OTHER ENDOSPERM GENES, ALONG WITH VARIOUS MODIFYING GENES IN VARIOUS BACKGROUNDS HAVE BEEN DEVELOPED DURING THE PROJECT, AND HAVE BEEN DISTRIBUTED TO A NUMBER OF LDC"S, EUROPEAN COUNTRIES, AND CORN BREEDERS IN THE US AND CANADA. ALTHOUGH THE PROJECT PURPOSE WAS NOT ACHIEVED, THE EXPENDITURE OF AID FUNDS IS CONSIDERED WORTHWHILE. MUCH KNOWLEDGE HAS BEEN ADDED TO THE FIELD OF BREEDING, GENETICS, AND BIOCHEMISTRY OF ENDOSPERM OF MAIZE; QUALITY AND QUANTITY OF PROTEIN; DEPOSITION OF STARCH; ASSOCIATED CHARACTERISTICS SUCH AS OIL CONTENT AND QUALITY, MINERAL CONTENT, STARCH COMPOSITION, AND INSECT AND DISEASE RESISTANCE; EFFECTS OF ASSOCIATED GENES BOTH SINGLY AND IN COMBINATION WITH OPAQUE-2; AND THE NUTRITIONAL VALUE OF MAIZE WITH VARIOUS QUALITIES OF PROTEIN. A TOTAL OF 120 PUBLICATIONS AND ABSTRACTS OF RESEARCH REPORTS, SYMPOSIA, AND WORKSHOPS HAVE BEEN PRODUCED. ALSO 700 COPIES OF THE ANNUAL RESEARCH REPORT HAVE BEEN DISTRIBUTED TO COOPERATORS AND INTERESTED CENTERS, MISSIONS, AND INSTITUTIONS IN MORE THAN 35 COUNTRIES.