• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.117-122
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• 2013

BACKGROUND: The scab, which is caused by Venturia nashicola, gives serious damages to pear trees. 'Niitaka' accounts for 82% of areas in pear cultivation. However 'Niitaka' is a scab susceptible cultivar. So, most of Korean farmers who growing pear trees have suffered by economic losses with the scab. In this research, we evaluated the scab resistance among elite pear seedlings to clarify genetics about the scab resistance. And we analyzed photosynthetic features with these seedlings to develop suitable cultivar which is advantageous for producing quality fruits during the growth and development of plants. METHODS AND RESULTS: We measured the rates of scab incidence among seedlings in a field experiment condition and an in-vitro test. An in-vitro test has been done with field experiment-based results. We made plant materials by grafting branches of each seedlings with 'Kongbae' rootstocks. And they had been grown for one month. Then, scab conidia suspension is sprayed to seedlings and sustained for 40 days under the controlled environment. As the results, 6 seedlings displayed lower incidence rates than other seedlings and 'Niitaka'. We also measured instant photosynthetic rates of each seedlings to determine the correlation between photosynthetic rates and fruit characteristics. However, it seemed that there is no correlation between them. CONCLUSION(S): Among the seedlings, 6 seedlings displayed the higher resistance to scab than other seedlings and 'Niitaka'. This characteristics is considered to be come from the gene expression of European pear. And we found that photosynthetic rate in trees rarely does not influence the fruit characteristics. It is considered to be affected by cultivar's own characteristics.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1782-1786
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• 2015

A new improved PCR method has been developed for the rapid, reliable, and sensitive detection of Venturia nashicola, a destructive pathogen of scab disease in Japanese pear. The translation elongation factor-1 alpha gene-derived PCR primers specifically amplified a 257-bp-sized DNA band of the target gene from the genomic DNA of V. nashicola. No amplicon was produced from the genomic DNA of other Venturia spp. and reference fungal species tested. With the high detection limit of 10 fg DNA content, our real-time method could be used for the quarantine inspection and field monitoring of V. nashicola.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.39.1-39
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• 1999

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.354-357
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• 2009

"Wonkyo Na-heukseong 2" was selected from a cross between "Kiyomaro", late season European cultivar with highly resistance and "Mansoo", late season Asian cultivar with long storability, large size and low susceptibility to pear scab made in 1997 at the National Institute of Horticultural & Herbal Science of Rural Development Administration in Korea. "Kiyomaro", released cross between "Taiheiyo" and "Bartlett" with scab resistance caused by Venturia nashicola in Japan, with no visual symptoms on any leaves was used as scab resistant source after field investigation and artificial inoculation test during 1997~1999. "Wonkyo Na-heukseong 2" blooms 1 day earlier than "Mansoo" and 3 days later than "Kiyomaro" in 2008. It is strong in tree vigor and upright-spreading in tree habit. It is classified as highly resistant to pear scab as "Kiyomaro" and "Bartlett", and cross-compatible with parental variety and Korean major pear varieties such as "Niitaka" and "Wonwhang". The average optimum harvest time of "Wonkyo Na-heukseong 2" was approximately 180 days after full bloom and it matured about 20 days shorter than parental varieties. The fruit is spindle in shape and yellowish greenish brown in skin color. Average fruit weight was 484 g and soluble solids content was $13.2^{\circ}Brix$. The flesh had medium to high juice and negligible grit. Its fruit was crisp like Asian pear.

• 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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.63.2-63
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• 2002

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.384-385
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• 2008

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.76.1-76.1
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• 2005

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.617-627
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• 2013

This study was conducted to survey the current pest occurrence and grower's pest management practices, and to investigate biodiversity including birds, snakes, rodents, and amphibians in organic pear orchards. From the questionnaires and field survey of 22 organic orchards in 2010, the materials such as lime sulphur, plant extracts and their mixtures with microorganisms, and oils were preferred over insecticides. Scab, mealybugs, woollybugs and barkminers were the major pests for organic pear growers. Environment-friendly fungicides and insecticides were applied 9 to 10 and 5 to 6 times respectively. Incidence and severity of scab on Niitaka pear fruits in organic orchards was higher than in conventional ones. Whereas for mealybugs there was no significant difference between organic and conventional orchards. Pear fruits in organic orchards were significantly smaller than those of non-organic orchards. For the biodiversity of amphibians, snakes, pheasants, and rodents, there was no significant difference between organic and conventional orchards, but Rufous turtle doves were monitored more in organic areas than in conventional ones.