Showing papers on "Amaranthus hypochondriacus published in 1991"

Interspecific hybrids and possible phylogenetic relations in grain amaranths

Abstract: Phylogenetic relations among the three species in grain amaranth need investigation to provide information for breeding experiments germplasm conservation efforts, and decision on evolutionary patterns in the grain types. Hybrid development from crosses between species was studied to find out genetic relationship between them. Interspecific crosses were made among Amaranthus hypochondriacus, A. caudatus and A. cruentus in the glasshouse. The F1 plants were relatively easy to obtain but had low pollen fertility (10.3–15.1%) and low seed set. A few of these hybrids did not produce seeds. Only a few F1 seeds obtained in crosses between A. cruentus and A. caudatus. All the F1 plants from these crosses died at the seedling stage. Crosses between A. cruentus and A. hypochondriacus produced few seeds. Most of the F1 plants obtained from the seeds died at the seedling stage with only four plants growing to maturity but were sterile. Based on hybrid development, it was suggested that A. hypochondriacus and A. caudatus were genetically closer than the other two combinations of species studied. A. cruentus seemed to be genetically closer to A. hypochondriacus than it was to A. caudatus.

Isolation, purification, and characterization of the oligomeric seed globulin from Amaranthus hypochondriacus

Abstract: The main storage seed protein of Amaranthus hypochondriacus, the oligomeric salt-soluble globulin, was isolated and purified to homogeneity by Sephacryl S-300 gel filtration and Separon Hema-Bio 1000 DEAE anion-exchange chromatography. The globulin had two heterogeneous forms, a major and minor species with apparent molecular masses of 398,000 and 337,000 daltons, respectively. Each of the two species were analyzed by sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (PAGE) and by native-PAGE (without prior reduction of disulfide bonds). Only slight differences were observed in their subunit patterns although appreciable differences in mobility and dissociation behaviour were noted on native-PAGE. The major protein fraction was oligomeric, consisting of a tetrameric and hexameric moiety held together by weak secondary forces. The minor fraction, a hexamer of slightly higher apparent molecular mass was a polymeric species derived in part from a sulfhydryl-disulfide interchange reaction.

Extraction of Two Albumin Fractions from Amaranth Grains: Comparison of Some Physicochemical Properties and the Putative Localization in the Grains

Abstract: Two alfiumin fractions were extracted from defatted flours of seeds of Amaranthus hypochondriacus and A. cruentus. One fraction (Alb-1) was extracted with 0.5m NaCl or water when used as the first solvent. Another fraction (Alb-2) was extracted with water after removing Alb-1 and globulin. Apparent pIs of Alb-1 and Alb-2 were 4.5–7.5 and 5–6, respectively. Alb-2 was precipitated by various metal ions (1 mm), while Alb-1 was not. Alb-2 contained four major components (Mr = 56, 36, 26, 22 kD), although Alb-1 had no particular major proteins. Pronase treatment of amaranth flour before protein extraction decomposed Alb-1, but not Alb-2, as seen by SDS-PAGE analysis. The findings that Alb-2 was protected from the Pronase treatment and it could not be extracted until Alb-1 and globulin were removed suggests that Alb-2 might be associated with protein bodies [Irving et al., J. Food Sci., 46, 1170 (1981)].

Saponins from Amaranthus hypochondriacus.

Abstract: Four triterpenoid saponins were isolated from Amaranthus hypochondriacus which are grain crops in the Nepal, Mexico and South America. Their structures were elucidated based on spectral evidence to be: (1) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta,3 beta-dihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester. (2) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta,3 beta- dihydroxyolean-12-en-23-al-28-oic acid 28-O-beta-D-glucopyranosyl ester; (3) 3-O-alpha-L-rhamnopyranosyl(1----3)-beta-D-glucuronopyranosyl-2 beta, 3 beta-dihydroxy-30-norolean-12,20(29)-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester. (4) 3-O-alpha-L-rhamnopyranosyl (1----3)-beta-D-glucuronopyranosyl-2 beta, 3 beta-dihydroxy-30-norolean-12, 20(29)-dien-23-al-28-oic acid 28-O-beta-D-glucopyranosyl ester.

The Rate of Outcrossing in Grain Amaranths

Abstract: Studies of intra specific and inter specific out crossing rates were carried out for grain amaranths using two populations of A. hypochondriacus (populations 1008 and 1024) and two populations of A. cruentus (populations 1034 and 434). The studies were conducted at Kabete Campus, University of Nairobi and National Horticultural Research Station, Thika, during the months April to August 1988 and October 1988 to February 1989. The mean intra specific out crossing rate estimates for A. hypochondriacus and A. cruentus were 10.4 % and 10.9 % respectively. The mean inter specific out crossing rate involving population 1024 as the dominant marker parent and 1034 as the recessive marker was 1.2 percent. The study involving population 434 as the dominant marker parent gave the mean inter specific out crossing rate as 6.5 percent. The intra specific and inter specific out crossing rate estimates showed substantial variation. Significant differences in out crossing rate estimates were noted due to locational and seasonal variations. The factors probably contributing to the variations were believed to be locational and seasonal differences in pollinator density and differences among the populations.