A split-plot experiment was conducted to study the optimum planting density of Nuomi yam in directional groove shallow cultivation. Nuomi yam was the main local cultivar of Dioscorea. The study of this paper may help to give valuable instructions of local production. Three different planting densities and shallow groove diameter were designed in the experiment. The results showed that the fresh weight of aerial part per plant, yield and planting benefit of Nuomi yam tuber were the highest when the planting density was 12 000 plants/hm~2 and the diameter of shallow growth groove was 11.0 cm, while they were the lowest when the planting density was 22 500 plants/hm~2 and the diameter of shallow growth groove was 7.5 cm. Along with the increase of planting density, the fresh weight of aerial part, tuber, fresh yield, benefit and commercial tuber rate of Nuomi yam also decreased. The commercial tuber rate of Nuomi yam of 11.0 cm diameter in shallow growing pot was the highest, while it was the lowest with no shallow growing pot. On the contrary, the content of amylopectin and mucin was the highest when there was no shallow groove, and was the lowest when the diameter of shallow groove was 7.5 cm, although there was no significant difference between the two treatments. Therefore, Nuomi yam with the directional cultivation combination of planting density of 12 000 plants/hm~2 and shallow groove diameter of 11.0 cm showed high yield, good appearance quality, high planting benefit and no obvious adverse effect on internal quality.
Dioscorea

Leaf spot symptoms were frequently observed on yam plants grown in the Yeoju area in Korea during a disease survey in 2008. A total of five isolates of Pseudophloeosporella sp. were obtained from the infected leaves of yam plants. All of the isolates were identified as Pseudophloeosporella dioscoreae based on their morphological and cultural characteristics. A phylogenetic tree derived from the internal transcribed spacer sequences of the fungal isolates showed that the fungus is distinctly separated from species in other related genera. P. dioscoreae isolates caused very tiny spots on leaves of yam plants two weeks after artificial inoculation which were similar to those observed in the field. This is the first report that Pseudophloeosporella dioscoreae causes leaf spot in yams in Korea.
Cultural Characteristics ; Dioscorea ; Fungi ; Korea

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on beta-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.
Dioscorea ; Fungi ; Korea ; Penicillium ; Sequence Analysis ; Tubulin

Animals ; Diabetic Nephropathies ; drug therapy ; Dioscorea ; chemistry ; Polysaccharides ; pharmacology ; Rats

To study the chemical constituents of Dioscorea zingiberensis Wright, the EtOH extract of fresh rhizomes of D. zingiberensis was concentrated and partitioned further to produce petroleum ether-, ethylacetate-, n-butanol- and water-soluble fractions. The water-soluble fraction was subjected to column chromatography on macro resin AB-8, and the final products were obtained by repeated reversed-phase ODS and MCI gel CHP 20P column chromatography. Structures of compounds were elucidated by 1H NMR, 13C NMR, 135DEPT, HMQC, HMBC and TOCSY spectroscopic analyses. A new steroidal saponin was isolated, which was identified as (25R)-26-O-(beta-D-glucopyranosyl)-furost-5-en-3 beta, 16, 20, 26-tetraol-22-seco-3-O-beta-D-glucopyranosyl-(1--> 3)-beta-D-glucopyranosyl-(1--> 4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside. The compound is a novel skeletally steroidal saponin, named as zingiberenin F (1). It was reported for the first time from D. zingiberensis Wright.
Dioscorea ; chemistry ; Molecular Structure ; Plants, Medicinal ; chemistry ; Rhizome ; chemistry ; Saponins ; chemistry ; isolation & purification

Diosgenin is an important raw material in steroid hormone and widely used in pharmaceutical industry. The traditional method for diosgenin production is acidolysis, which causes serious pollution. In order to obtain a cleaner and more efficient approach of diosgenin production, a strain of Gibberella intermedia WX12 (the sexual stage of Fusarium proliferatum) was screened from the strains deposited in our laboratory. This strain converted saponins in Dioscorea zingiberensis C.H. Wright (DZW) into diosgenin. The conversion medium was optimized by statistical experimental design. The optimized conversion medium was as follows (g/L): glucose 20.6, yeast extract 5.0, NaCl 1, K2PO4 3, ZnSO4 x 7H2O 1.5 and saponins 3. Under the optimal conditions, the yield of diosgenin achieved to (31 +/- 0.3) mg/g DZW, which was 3 times higher than that of the original medium.
Biotransformation ; Culture Media ; Dioscorea ; chemistry ; Diosgenin ; metabolism ; Gibberella ; growth & development ; metabolism ; Saponins ; metabolism

OBJECTIVETo perfect the current standard of Rhizoma Diosoreae and Rhizoma Diosoreae stir-baked with bran by improving quality standards of the two processed pieces.

METHODThe quality standards were established according to 9 batches of processed pieces, separately. The standards contains items of identification, water, total ash, acid-insoluble ash, extractives, heavy metals limit, organochlorine limit, microbial limit and assay.

RESULTThe TLC of the two pieces was characteristed. The contents of acid-insoluble ash in the two pieces were increased, not more than 0.5%, 0.3%, respectively. The content limits of five kinds of heavy metals and harmful elements, two kinds of residual organochlorine pesticides and three microbial limits were increased. There were no more than 2 x 10(-7) of lead, 2 x 10(-7) of cadmium, 1 x 10(-5) of copper, 3 x 10(-7) of arsenic, 1 x 10(-7) of mercury, 1 x 10(-7) of hexachlorocyclohexane (BHC) and 1 x 10(-7) of chlorophenothane (DDT) in the two processed pieces, respectively. There were no more than 2 000 and 600 cfu x mL(-1) in the two pieces, respectively and no more than 30 MPN x 100 g(-1) and fungi can not be tested in the two pieces. The contents of allantoin in the two pieces were no more than 0.15%.

CONCLUSIONThis method is simple and suitable for the quality control of the two processed pieces.

To breed a new yam cultivar of Dioscorea alata, the different and excellent germplasm resources were investigated within artificially cultivated population and some superior individuals, with a higher yield and medicinal properties, were selected. Considering results of the yield and medicinal properties during 2006-2013 cropping season, strains and lines were established and selected. As a result, the yield of the new developed cultivar (Wenshanyao No. 1, WSY01-1) reached 2217. 0 kg per 667 m2 (fresh weight) and 348.3 kg per 667 m2 (dry weight), and increased 23.8% and 23.9% comparing with control cultivars (landraces). Comparing with control cultivars, the level of polysaccharide, allantoin, and dioscin increased 36.9%, 48.3%, 20.9%, and reached 12.2%, 1.30%, 579.7 µg · g(-1), respectively. This result showed that the systematic selection method can significantly improve yield and medicinal properties of D. alata, and the developed " Wenshanyao No. 1" exhibits wide spreading prospects.
Allantoin ; analysis ; Breeding ; Dioscorea ; chemistry ; genetics ; growth & development ; Diosgenin ; analogs & derivatives ; analysis ; Polysaccharides ; analysis

OBJECTIVETo extract polysaccharides from Dioscorea opposita by alpha-amylase and ultrasound.

METHODThe optimum condition of enzyme-assisted extraction has been obtained through orthogonal test according to the yield of polysaccharides.

RESULTA higher yield of polysaccharides was achieved at 55 degrees C, pH 5.5 , with a load of alpha-amylase 10 mg for 1.0 hour, the extraction rate was increased by in compare of sonolysis treatment alone.

CONCLUSIONTo carry out an enzyme treatment before ultrasound--assisted extraction elevated the yield of polysaccharides.

Yam (Dioscorea opposita) is commonly consumed in East Asia, but allergic reaction to this plant food is rare. To date, there is no report of anaphylactic reaction after ingestion of cooked yam. We described 3 cases with anaphylaxis after eating boiled yam and 1 present with oral allergy syndrome as well. Basophil activation test in patients showed positive reactivity to boiled yam extract. In immunoblotting, a 30-kDa protein was recognized by all patients' sera and a 17-kDa band was detected by 1 patient. N-terminal amino acid revealed the 30-kDa IgE reacted band was DB3S, dioscorin in Dioscorea tuber. It promoted us that DB3S was a thermal stable oral allergen to trigger anaphylactic reaction and oral allergy syndrome in cooked yam (D. opposita) allergy. Patients with this plant food allergy should avoid both raw and well-cooked yam.
Anaphylaxis ; Basophils ; Dioscorea ; Eating ; Far East ; Food Hypersensitivity ; Humans ; Hypersensitivity ; Immunoblotting ; Immunoglobulin E ; Plants