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Castor is an industrial oilseed crop with great potential for biorefineries. However, little is known about the variability in the bioactive compounds in castor germplasm. This study evaluated seed weight, oil content, fatty acid profile, tocopherols, and phytosterols in 160 accessions of the USDA-ARS castor germplasm collection. The accessions were grown in Cordoba, Spain, under three different environmental conditions. Environmental and genotype-by-environment interaction effects were predominant for most traits, resulting in moderate to low broad-sense heritabilities, which ranged from 0.12 for total tocopherol content to 0.88 for hundred-seed weight. The genetic variability in the seed quality traits identified in the collection was lower than that reported previously for the germplasm of wild and semi-wild accessions from Spain, which is attributed to the lower genetic diversity in cultivated than in wild forms. The variation in seed quality traits in castor germplasm can be exploited to improve the concentration of bioactive compounds in castor cultivars. [ABSTRACT FROM AUTHOR]

With 1 figure and 1 table Abstract Sunflower seeds and oil are one of the richest natural food sources of alpha-tocopherol (vitamin E). The sunflower line IAST-413, with enhanced alpha-tocopherol content, was developed by pedigree selection. The objective of this research was to study the inheritance of increased tocopherol content in seeds of IAST-413. Plants of this line were reciprocally crossed with plants of line HA89 with wild-type tocopherol content, and their F1, F1r, F2, F2r, BCP1 and BCP2 generations were evaluated in the field in 2006 and 2007. The F3 generation was evaluated in the field in 2007. Estimated broad-sense heritability () was 0.78 in 2006 and 0.67 in 2007, whereas narrow-sense heritability () was 0.70 in 2006 and 0.60 in 2007. Estimate of heritability through parent-offspring correlation was 0.67 and realized heritability was 0.64. The estimated minimum number of genes conditioning increased levels of tocopherol was 1.04 in 2006 and 1.95 in 2007. This mode of inheritance and response to selection should facilitate the introgression of the trait into elite germplasm to develop sunflower oil naturally rich in vitamin E. [ABSTRACT FROM AUTHOR]

Genetic control of the synthesis of high gamma-tocopherol (gamma-T) content in the seed oil of safflower ( Carthamus tinctorius L.) and development of highly reliable molecular markers for this trait were determined through molecular tagging and candidate gene approaches. An F2 population was developed by crossing the high gamma-T natural mutant IASC-1 with the CL-1 line (standard, high alpha-T profile). This population segregated for the partially recessive gene Tph2. Bulked segregant analysis with random amplified polymorphic DNA (RAPD) and microsatellite (SSR) markers revealed linkage of eight RAPD and one SSR marker loci to the Tph2 gene and allowed the construction of a Tph2 linkage map. RAPD fragments closest to the Tph2 gene were transformed into sequence-characterized amplified region markers. A gamma-T methyltransferase (gamma-TMT) locus was found to co-segregate with Tph2. The locus/band was isolated, cloned and sequenced and it was confirmed as a gamma-TMT gene. A longer partial genomic DNA sequence from this gene was obtained. IASC-1 and CL-1 sequence alignment showed one non-synonymous and two synonymous nucleotide mutations. Intron fragment length polymorphism and insertion-deletion markers based on the gamma-TMT sequence diagnostic for the Tph2 mutation were developed and tested across 22 safflower accessions, cultivars, and breeding lines. The results from this study provide strong support for the role of the gamma-TMT gene in determining high gamma-T content in safflower and will assist introgression of thp2 alleles into elite safflower lines to develop varieties with improved tocopherol composition for specific market niches. [ABSTRACT FROM AUTHOR]

Safflower ( Carthamus tinctorius L.) seeds have a tocopherol fraction dominated by α-tocopherol, which accounts for more than 95% of the tocopherols. α-Tocopherol exerts a high vitamin E activity, but a low in vitro antioxidant action. For non-food applications, replacement of high α-tocopherol by γ-tocopherol is preferred. Because of the limited variability found in germplasm of cultivated safflower, the objective of the present research was to search for variability for tocopherol profile in germplasm of wild safflower species. Bulk seed samples of 77 accessions from six species were analysed for total tocopherol content and profile. One accession of C. oxyacanthus showed increased γ-tocopherol content (36%). Single-seed analysis showed the existence of a bimodal distribution, which included high α-tocopherol (>90%) and high γ-tocopherol (HGT) seeds (>85%). Plants from the HGT seeds bred true for the trait and showed introgression of cultivated safflower, which allowed a rapid selection for cultivated safflower traits. Genetic analysis revealed that the HGT trait was controlled by partially recessive alleles at a single locus Tph1, which will facilitate the transference of the novel trait to diverse safflower germplasms. [ABSTRACT FROM AUTHOR]

α-Tocopherol is the main tocopherol in sunflower seeds (>90%). Because it exerts a weak antioxidant actionin vitro, its partial replacement by other tocopherols is an important breeding objective in this crop. The objective of this research was to develop novel tocopherol profiles in sunflower through mutagenesis and genetic recombination. Seeds of four‘Peredovik’ accessions were used for chemical mutagenesis with ethyl methane sulfonate (EMS). Single-seed screening in the M2 generation resulted in two M2 seeds, derived from different M1 plants, with increasedγ-tocopherol contents of 19.2% and 96.7%, respectively. M3 progeny from the M2 seed with the 96.7% content bred true for highγ-tocopherol content, containing more than 90%γ-tocopherol. M3 progeny from the M2 seed with only 19.2%γ-tocopherol segregated in a range from 0 to 84.6%. Selection for highγ-tocopherol content produced an M4 : 5 line, designated IAST-1, with a stable high concentration ofγ-tocopherol. Crosses between IAST-1 and T589, with an increasedβ-tocopherol content, produced F2 segregants with transgressive levels of up to 77%β-tocopherol or up to 68%δ-tocopherol. Both novel tocopherol profiles were confirmed in the F3 generation. [ABSTRACT FROM AUTHOR]