• Journal of Plant Biotechnology
• /
• v.40 no.4
• /
• pp.203-209
• /
• 2013

Genetic manipulation of pear (Pyrus pyrifolia Nakai) breeding is still difficult due to lack of reliable regeneration system. The aim of this research is to establish shoot regeneration system from leaf explants for pear (P. pyrifolia cv. Niitaka) using various concentrations of plant growth regulators and carbon source supplemented to medium. The highest regeneration rate of about 20% was found on a medium containing 4.4 g/L of Murashige and Skoog (MS) without vitamins, Linsmaier and Skoog (LS) vitamins were added separately. Leaf explants of pear were cultured on MS medium containing 7 g/L of Daishin agar supplemented with various concentrations of NAA (0.01, 0.05, 0.1, 0.5 mg/L) in combination with BA(3, 5, 10 mg/L) for shoot regeneration. In medium with 5 mg/L of BA and 0.01 mg/L of NAA, adventitious shoot regeneration rate was higher than others treated. The optimal results were observed using MS medium supplemented with 30 g/L sorbitol as carbon source on regeneration system. Sorbitol is considered better carbon source than sucrose for shoot regeneration of pear (P. pyrifolia cv. Niitaka). In order to increase of shoot regeneration in pear (P. pyrifolia cv. Niitaka), plant agar and Daishin agar used as gelling agents, Daishin agar is more efficient in shoot regeneration.

• Journal of Korean Society of Forest Science
• /
• v.59 no.1
• /
• pp.37-45
• /
• 1983

Taxonomic distribution of ecto- and endomycorrhizae among woody species growing in Korea was studied and their distribution was compared with foreign literature, Most of root samples were collected from Central Branch Station of forest Research Institute in Gwangneung, Gyonggido. A total of 32 families, 63 genera, 102 species were examined. Ectomycorrhizae were observed in the following 13 general of Pinaceae (Pinus Larix, Picea, Abies), Salicaceae (Populus, salix), Betulace (Alnus, Betula, Carpinus, Corpylus), Fagaceae(Quercus, Casianea), and Tiliaceae (Tilia), Endomycorrhizae (vesicular-arbuscular) were observed in Populus and the rest of the 49 genera. Rhus was the only genus which did not have either ecto- or endomycorrhizae, while foreign literature listed following genera having both mycorrhizal types: Juniperus, Cupressus, Populus, Salix, Juglans, Alnus, Ulmus, Malus, Pyrus, and Tilia. Juniperus, Ulmus, Pyrus, and Acer which were reported to have facultative ectomycorrhizae were free of ectomycorrhizae, Some morphological characteristics of endomycorrhizae are shown in photogrphs and discussed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.2
• /
• pp.195-202
• /
• 2008

This study was performed to examine the effects of electron beam irradiation on volatile flavor components of Shingo pear (Pyrus pyrifolia cv. Niitaka) and on their changes according to storing period following irradiation. Volatile flavor components in pear were extracted using simultaneous steam distillation and extraction (SDE) apparatus and analyzed by GC/MS. 46 components were identified in control whereas 45, 44, 48 and 51 components were identified in irradiated samples by electron beam at 0.25, 0.5, 1, and 3 kGy, respectively. Hexanal, n-hexanol, and (E)-2-hexenal were identified as the major volatile flavor components of all samples. The characteristic volatile flavor components of irradiated pear by electron beam were similar to those of control, and their effects depending on irradiation source were not different. In addition, there was no noticeable change in volatile flavor components of pear with storage at $4^{\circ}C$ for 30 days or with irradiation. Sensory evaluation indicated that the consumer receptiveness tended to be higher at a low level of radiation dose under 1 kGy than control, albeit not significant. Therefore, electron beam irradiation at low level of radiation dose under 1 kGy could be considered as an effective method to exterminate vermin and thus to improve the shelf-stability of pear without deterioration.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.546-552
• /
• 2010

The aim of the study was to assess the cosmeceutical activity of Pyrus ussuriensis leaves and it is possible that can be used as a cosmetic ingredient for application of cosmetic industries. P. ussurensis leaf was extracted with various solvents including water, 70% ethanol and 60% acetone. In the result of DPPH (1,1-diphenyl-2-picryl-hydrazyl) scavenging radical activity, water, ethanol and acetone extract of P. ussuriensis leaf were higher than 70%, 80% and 85% at 50 ppm concentration, respectively. Xanthine oxidase inhibition activity and superoxide dismutase (SOD)-like activity by P. ussuriensis extract were higher than 30%. In addition, SODlike activity of all extracts showed tendency of the significant increase with the increase of concentration. In the anti-inflammatory test, P. ussuriensis leaf extract inhibited generation of nitric oxide (NO) stimulated by LPS in the macrophage cell line (raw 264.7) after 12 to 24 hours. As above results, P. ussuriensis has a great potential as a cosmeceutical raw material as well as anti-oxidant and anti-inflammatory ability.

• Korean Journal of Breeding Science
• /
• v.41 no.4
• /
• pp.444-450
• /
• 2009

Amplified fragment length polymorphism (AFLP) marker was utilized for evaluation of genetic diversity of 60 pear germplasms. Twenty selective AFLP primer pairs generated a total of 522 polymorphic amplification products. From UPGMA (unweighted pair-group method arithmetic average) cluster analysis by using polymorphic bands, the pear germplasms were divided into four clusters by similarity index of 0.691. The first cluster (I) included European pears belonging to Pyrus communis and wild species such as P. nivalis and P. cordata. The second cluster (II) included Ussurian pea pears belonging to P. betulaefolia and P. fauriei. The third cluster (III) included pea pears belonging to P. calleryana and P. koehnei. Most of germplasms belonging to P. pyrifolia and P. ussuriensis, and interspecific hybrids were included in the fourth (IV) cluster. Therefore pear germplasms originated from East Asia were closely related to P. pyrifolia and P. ussuriensis. Similarity values among the tested pear germplasms ranged from 0.584 to 0.879, and the average similarity value was 0.686.

• Journal of Korean Society of Forest Science
• /
• v.100 no.2
• /
• pp.136-141
• /
• 2011

This study was conducted to confirm the application as ingredients of cosmetics through an examination of the function for anti-cancer and anti-microbial of the fraction isolated from Pyrus ussuriensis leaves. The dried leaf of P. ussuriensis were extracted with acetone-$H_{2}O$ (6:4, v/v), concentrated and fractionated with the upper layer of acetone on a separatory funnel. Each fraction was freeze dried, then a portion of acetone soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents and also used the MIC-gel using a series of aqueous methanol as developing solvent. The isolated compounds were identified by silica-gel TLC. The growth inhibition activity was measured using the MTT assay by the mouse meltioma (B16F10) cell. The cancer cell growth inhibition rate of fractions isolated from P. ussuriensis leaf was 80%. In anti-microbial activity test, the fraction of P. ussuriensis with 0.25 mg/disc resulted in the clear zone of 1.3 cm and 2 cm for Staphylococcus aureus and S. epidermidis of gram positive bacillus, respectively. In Escherichia coli of gram negative bacillus, the fraction with 0.5 mg/disc resulted in the clear zone of 1.1 cm~1.5 cm each fraction. From these results, we confirmed that acetate fraction of P. ussuriensis has a great potential as a natural ingredients with a anti-cancer and anti-microbial source.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.583-583
• /
• 2000

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.220-220
• /
• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2002.04a
• /
• pp.101-109
• /
• 2002

A lot of SSRs (simple sequence repeats) in peach and pear from enriched genomic libraries and in peach from a cDNA library were developed. These SSRs were applied to other related species, giving phenograms of 52 Prunus and 60 pear accessions. Apple SSRs could also be successfully used in Pyrus spp. Thirteen morphological traits were characterized on the basis of the linkage map obtained from an $F_2$ population of peach. This map was compiled with those morphological markers and 83 DNA markers, including SSR markers used as anchor loci, to compare different peach maps. Molecular markers tightly linked to new root-knot nematode resistance genes were also found. A linkage map including disease-related genes, pear scab resistance and black spot susceptibility, in the Japanese pear Kinchaku were constructed using 118 RAPD markers. Another linkage map, of the European pear Bartlett, was also constructed with 226 markers, including 49 SSRs from pear, apple, peach and chewy. Maps of other Japanese pear cultivars, i.e., Kousui and Housui, were also constructed. These maps were the first results of pear species.

• Journal of Korean Society of Forest Science
• /
• v.97 no.4
• /
• pp.452-457
• /
• 2008

In order to develop an efficient micropropagation technique effect of plant growth regulators (PGRs) affecting on shoot proliferation from shoot apex in Pyrus ussuriensis was tested. Generally, there was no conspicuous effect on shoot induction by the treatment of PGRs and one or two shoots/explant were induced when cultured on MS medium supplemented with BA and/or BA plus NAA. Both apical shoot necrosis and hyperhydric shoots were observed frequently in multiplied shoots, and callus was formed at the basal part of shoots. About 20% spontaneous rooting was achieved in growing shoots, however the proliferated shoots exhibited poor rooting rate in gelrite supported media. When we tried to ex vitro rooting of the shoot cutting, the shoot cuttings rooted up to 50% with 100 mg/L IBA application. The rooted plantlets grew normally after acclimatization in the greenhouse.