SDS-PAGE Analysis of Storage Proteins of Cultivated Rice Collected in Tanzania, 1988

During the trip from June 30 to August 10 in 1988, 105 seed samples of cultivated rice, Oryza sativa L., and a seed sample of O.glaberrima STEUD. were collected in Tanzania. Those were classified into 127 strains in O.sativa and 2 strains in O.glaberrima, according to the morphological observations. Seed storage proteins extracted from one rice seed of each strain were subjected to SDS-PAGE. The SDS-PAGE analysis of seed storage proteins was reported. Basing on the migration mode or staining intensity of the individual polypeptyde bands, strains were classified into three types for glutelin α subunits, tentatively named as types A, B and C (Fig. 2), and six types for 13 kDa polypeptides, tentatively named as types 1, 2, 3, 4, 5 and 6 (Fig. 3). Of 127 strains of O.sativa cultivars, 31 strains (24%) belonged to type A and 96 strains (76%) belonged to type B (Table 1). Type C was observed in two strains of O.glaberrima collected in Zanzibar Island. Geographical distribution of types A and B considerably differed among localities (Table 2). The frequencies of strains belonging to types A and B were 23% and 77% in Southwestern Area, 11% and 89% in Central and Western Areas, 33% and 67% in Northern Area, 16% and 84% in Eastern Area and 31% and 69% in Zanzibar and Pemba Islands, respectively. For 13 kDa polypeptides analysed by SDS-PAGE, types 1, 2, 3, 4 and 5 were found in the strains of O.sativa cultivars. Type 6 was observed in two strains of O.glaberrima (Table 1). The frequencies of strains belonging to types 1, 2, 3, 4 and 5 were found to be 20% (25 strains), 34% (43 strains), 24% (31 strains), 16.5% (21 strains), and 5.5% (7 strains), respectively. Geographical distribution of strains belonging to each type also differed considerably among the localities (Figs. 4A to 4E). The frequencies of strains belonging to types 1, 2, 3, 4 and 5 were found to be 23%, 54%, 11.5%, 11.5% and 0% in Southwestern Area, 53%, 26%, 11%, 5% and 5% in Central and Western Areas, 6%, 33%, 22%, 17% and 22% in Northern Area, 12%, 47%, 35%, 18% and 0% in Eastern Area and 13%, 22%, 36%, 24% and 4% in Zanzibar and Pemba Islands, respectively