• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.45-52
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• 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 Prunes 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 cherry. Maps of other Japanese pear cultivars, i.e., Kousui and Housui, were also constructed. These maps were the first results of pear species.

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

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

A lot of SSRs (simple sequence repeats) in peach and pear from enriched genomic libraries and in peach from a cDHA 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 Fa population of peach. This map was compiled with those morphological markers and 83 DHA 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 cherry. Maps of other Japanese pear cultivars, i.e., Kousui and Housui, were also constructed. These maps were the first results of pear species.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.180-185
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• 2002

Volatile flavor components in three pear varieties (Pyrus pyriforia N.) of traditional cultivar, Bongri, Hwangsilri and Yongmokri, were collected by SDE method using the mixture of n-pentane and diethylether as an extract solvent and were identified by GC/MS. Among 97 compounds identified from all varieties, there were 72, 58 and 66 components in Bongri, Hwangsilri and Yongmokri, respectively. Ethyl acetate was the dominant constituent in all cultivars and also volatile profiles contained large quantity of ethanol and acetic acid. Butyl acetate identified as a main component in Bongri was not found in other pears, but in Hwangrilri and Yongmokri only 4 to 5 esters played important role in total volatile flavor composition. The volatile profiles of these three varieties were characterized by compounds in group of aldehydes, esters, alcohols, acids and ketones. As classified by functional group of separated and identified components, esters and alcohols in Bongri, alcohols in Hwangsilri, and esters in Yongmokri were roled as the title in composition of volatile flavor components. Although small amount, Yongmokri had the highest rate of volatile production at 6.552 mg/kg of pear while Hwangsilri produced the lowest at 4.175 mg/kg of pear.

• Food Science and Preservation
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• v.17 no.4
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• pp.466-470
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• 2010

We investigated the effects of organic mulches on the tree and fruit qualities of "Niitaka" (Pyrus pyriforia) pear trees. Trees grown with rice straw mulch had significantly greater potassium (K), magnesium (Mg), and calcium (Ca) concentrations in leaves compared with control trees and those mulched using bark or polyethylene, but the concentrations were below the recommended levels for these nutrients in pear leaves. Bark mulch increased fruit firmness and soluble solid (SS) levels, compared with rice straw mulch. The fruit of trees grown with bark mulch had a higher ratio of SS to total acidity in fresh fruit, and the fruit was dark red in color. The K and Ca concentrations were highest in fruit grown on trees mulched with rice straw and bark, respectively, and competition between the levels of these cations was evident in fresh fruit. Bark and rice straw mulches increased overall fruit quality, and reduced fruit stone size, whereas a polyethylene mulch, devoid of organic material, resulted in a fruit stone size similar to that of the control.

• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.543-551
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• 2011

This study was conducted to evaluate nutrient production of both orchardgrass and several clovers as a green manure in a 'Niitaka' pear (Pyrus pyriforia) orchard. The experiment was conducted at diligent farmer in Boseong in Chonnam on March 26 of 2010, and the treatments included; 1) orchard grass (2.0kg/$1,000m^2$), 2) orchard grass (1.0kg/$1,000m^2$)+ladino clover (1.0 kg/$1,000m^2$), 3) orchard grass (1.0kg/$1,000m^2$)+red clover (1.0kg/$1,000m^2$), and 4) orchard grass (1.0kg/$1,000m^2$) +white clover (1.0kg/$1,000m^2$). Lengths of orchardgrass and clovers were greater in July than those of June and September. Seeding of orchardgrass without clovers in June and July increased dry weight of green manure crops compared with the seeding of orchardgrass with clovers, resulting in greater annual total dry weight. Various green manure treatments produced different amounts of total N and $P_2O_5$ from each raw materials and did not satisfy amounts of those nutrients for proper annual growth of ten- to twelve-year-old pear tree. Amounts of $K_2O$ producing from green manures, however, satisfied for proper growth of the pear trees.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.567-575
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• 2009

Organic pear (Pyrus pyriforia) fruits have remarkably increased in Korea since year 2000 due to increase consumer's demand for the fruit, and the farmers are keep trying to change their cultivation system that is replaced from conventional farming to organic-base farming for the fruit. However, there is little information for the soil properties, tree nutrition, and tree growth at organic orchards in Korea. Therefore, this study was established to investigate for the chemical properties of soils and leaf and bud characteristics of a conventional and organic pear trees in experimental orchards for two years. Commercial (Sanwool, YoungHwa Co., Korea) compost was applied to the orchard soils with conventional farming systems for two years for pear trees (10 to 15 year old trees) in KyungSan, Korea. The compost application increased pH, organic matter content, cation exchange capacity (CEC), and, microbial biomass in the soil. The compost treatment also increased specific leaf weight and foliar $P_2O_5$ concentration as well as leaf and floral bud sizes.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.85-89
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• 2012

To investigate the bird's dieting behavior for several fruits in orchards, this study was carried out in 2008. Black-billed magpies (Pica pica), azure-winged magpies (Cyanopica cyanus), and brown-eared bulbuls (Hypsipetes amaurotis) made their unique marks on the surface of pear and apple fruits; black-billed magpies pecked fruits strongly and left round holes with perpendicular angle, whereas those of azure-winged magpies and brown-eared bulbuls were sack-shaped with narrow neck and marked unique stripes on the skin. For the fruits of pear and apple from bagging practices, the birds showed different foraging behavior; black-billed magpies could injure all kinds of fruits whether with paper bags or not, but azure-winged magpies and brown-eared bulbuls could not attack the fruits with paper bag. Azure-winged magpies and brown-eared bulbuls preferred pear fruits to those of apples and satsuma mandarins in the cage trials. To reduce the injuries by azure-winged magpies and brown-eared bulbuls on pear and apple fruit, wrapping bag should not be impaired. Introducing azure-winged magpies to Cheju should be prohibited for the potential citrus injury by them.

• Food Science and Preservation
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• v.16 no.3
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• pp.317-320
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• 2009

'Niitaka' (Pyrus pyriforia) has been the major cultivar of the Asian pear since the 1970s, and yielded about 70% of pear production in South Korea in 2002. When Chuseok (Korean Thanksgiving Day) is earlier than the fruit maturation period, farmers seek to advance the harvesting date to keep pace with the increase in consumer demand caused by the holiday. However, unripened fruit is of suboptimal marketable value because the flesh has a low soluble solid content, the fruit color is not attractive, and stone volume is high. Compost treatment can enhance soil microbial activity and affect soil chemistry, which may accelerate fruit maturation and allow an earlier harvesting date. Therefore, we examined the effect of 2 years of compost application on the fruit quality of Asian pear trees grown under conventional management conditions. The Hunter "L" and "a" values were higher in compost-treated fruit, which also showed greater sweetness and lower acidity than did conventional fruit. The stone volume was reduced and fruit calcium concentration was increased by compost treatment. Therefore, compost treatment may advance fruit harvesting owing to the increased marketability afforded by attractive skin color, sweetness, and reduced stone volume.

• Food Science and Preservation
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• v.16 no.3
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• pp.305-310
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• 2009

This study was conducted using 8-year-old 'Niitaka' (Pyrus pyriforia) pear trees to investigate the effect of different organic fertilizers on fruit quality and level of total phenolicsin a conventionally managed orchard. Trees were treated with one of five different fertilizers: 1) control (60 g of chemical fertilizer [16N-11P-12K] per tree) 2) rice bran (RB, 10 kg per tree); 3) coffee bran compost (CBC, 10 kg per tree); 4) chitin-incubated compost (CIC, 10 kg per tree); or 5) RCC (RB+CBC+CIC, 30 kg per tree). Soluble solid content, hardness, and titratable acidity were significantly higher in fruit from RCC-treated trees compared with fruit from trees exposed to other treatments. Overall, control fruit had smaller stones and lower calcium concentration than had organically fertilized fruit. Also, control fruit showed a reduced level of total phenolic compounds and lower antioxidant activity in both peel and flesh than did organically fertilized fruit. Compost-treated trees yielded fruit of enhanced edibility and with longer shelf-life owing to a reduction in stone size and increased calcium concentration, respectively. Overall, fruit from trees treated with organic fertilizers was of higher quality and had greater antioxidant levels compared with fruit from trees treated with chemical fertilizer.