The characteristics of cork and hypodermis tissues and cracking in Asian pear (Pyrus pyrifolia cv. Mansoo)

2016 ◽  
Vol 199 ◽  
pp. 224-228 ◽  
Author(s):  
YongHee Kwon ◽  
Hyun-Hee Han ◽  
Hee-Seung Park
Keyword(s):  
Pyrus Pyrifolia ◽  
Asian Pear

Pathogenic Specialization of Venturia nashicola, Causal Agent of Asian Pear Scab, and Resistance of Pear Cultivars Kinchaku and Xiangli

2020 ◽  
Author(s):  
Hideo Ishii ◽  
Kumiko Nishimura ◽  
Kenji Tanabe ◽  
Yuichi Yamaoka
Keyword(s):  
Resistance Breeding ◽  
Scab Resistance ◽  
Japanese Pear ◽  
Pyrus Pyrifolia ◽  
Asian Pear ◽  
Sexual Recombination ◽  
Venturia Nashicola ◽  
Race 1 ◽  
New Races ◽  
Race 2

Scab, caused by Venturia nashicola is one of the most serious diseases of Asian pears including Japanese pear (Pyrus pyrifolia var. culta) and Chinese pears (P. bretschneideri and P. ussuriensis). Breeding of scab-resistant pear cultivars is essential to minimize the use of fungicides and the risk of fungicide resistance developing in the pathogen. A survey of pathogenic specialization in V. nashicola is needed to ensure durable scab resistance in cultivated pears. Race 1, 2, and 3 isolates of V. nashicola, each differing in pathogenicity to Japanese pear cv. Kousui and Asian pear strain Mamenashi 12, have been reported from Japan. In the present study, isolates collected from scabbed pears in China and Taiwan were classified as V. nashicola based on conidial size and mating ability. However, various isolates were found to have pathogenicity distinct from races 1, 2, and 3 in tests on seven differential host genotypes: Kousui; Mamenashi 12; Chinese pear cvs. Jingbaili, Yali, Linyuli, Nanguoli; and Taiwanese pear cv. Hengshanli. The new races were designated as races 4 to 7. Progenies characteristic of race 3 isolates were produced in a cross between race 1 and race 2 isolates, suggesting the possible role of sexual recombination in the emergence of novel races. Japanese pear cv. Kinchaku and cv. Xiangli of P. sinkiangensis (Korla fragrant pear grown in China) didn’t show visible symptoms after inoculation with any of the seven races. The broad scab resistance in Kinchaku and Xiangli makes them a promising genetic resource for resistance breeding programs.

scholarly journals Genome-Wide Identification and Analysis of High-Copy-Number LTR Retrotransposons in Asian Pears

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 156
Author(s):  
Shuang Jiang ◽  
Xiaoqing Wang ◽  
Chunhui Shi ◽  
Jun Luo
Keyword(s):  
Copy Number ◽  
Long Terminal Repeat Retrotransposons ◽  
High Copy Number ◽  
Pyrus Pyrifolia ◽  
Origin And Evolution ◽  
Asian Pear ◽  
Copy Numbers ◽  
Genome Wide ◽  
History Of ◽  
Insertion Sites

A large proportion of the genome of ‘Suli’ pear (Pyrus pyrifolia) contains long terminal repeat retrotransposons (LTR-RTs), which suggests that LTR-RTs have played important roles in the evolution of Pyrus. Further analysis of retrotransposons, particularly of high-copy-number LTR-RTs in different species, will provide new insights into the evolutionary history of Pyrus. A total of 4912 putative LTR-RTs classified into 198 subfamilies were identified in the ‘Suli’ pear genome. Six Asian pear accessions, including cultivars and wild species, were resequenced. The comparison of copy number for each LTR-RT subfamily was evaluated in Pyrus accessions, and data showed up to four-fold differences for some subfamilies. This contrast suggests different fates for retrotransposon families in the evolution of Pyrus. Fourteen high-copy-number subfamilies were identified in Asian pears, and more than 50% of the LTR-RTs in the genomes of all Pyrus accessions were from these 14 identified LTR-RT subfamilies. Their average insertion time was 3.42 million years ago, which suggests that these subfamilies were recently inserted into the genome. Many homologous and specific retrotransposon insertion sites were identified in oriental and occidental pears, suggesting that the duplication of retrotransposons has occurred throughout almost the entire origin and evolution of Pyrus species. The LTR-RTs show high heterogeneity, and their copy numbers vary in different Pyrus species. Thus, our findings suggest that LTR-RTs are an important source of genetic variation among Pyrus species.

The Presence of a New S-RNase Allele (S10) in Asian Pear (Pyrus pyrifolia (Burm; Nakai))

2006 ◽  
Vol 53 (7) ◽  
pp. 1375-1383 ◽  
Author(s):  
Hoy-Taek Kim ◽  
Yutaka Hirata ◽  
Hyun-Jung Kim ◽  
Ill-Sup Nou
Keyword(s):  
Pyrus Pyrifolia ◽  
Asian Pear

scholarly journals (309) Effect of Chitin-incubated Solution (CIS) Spray on Tree Growth and Fruit Quality of `Niitaka' Asian Pear

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1025E-1026
Author(s):  
Wol-Soo Kim ◽  
Jung-An Jo ◽  
Soon-Ju Chung ◽  
Kil-Yong Kim ◽  
Hyun Sug Choi
Keyword(s):  
Room Temperature ◽  
Specific Weight ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Pyrus Pyrifolia ◽  
Fruit Characteristics ◽  
Chlorophyll Contents ◽  
Asian Pear ◽  
Flesh Browning

The shells of crab, shrimp, beetles, etc., could be decomposed by chitinase to chitin, calcium, and protein, respectively. We incubated the mixture solution of 1.5 kg crab shell, 1.5 kg multinutrient, 2 kg compost with microorganisms to decompose the chitin substance, 3 kg sugar, and 700 L water at room temperature for 7 days. During the incubation, aeration with an air pump was essential. We sprayed the chitin-incubated solution (CIS) after filtering to `Niitaka' pear (Pyrus pyrifolia) trees at 15-day intervals from May to Sept. 2004. Leaf area, leaf thickness, leaf specific weight, and chlorophyll contents were increased by the treatment with CIS. In fruit characteristics, fruit weight, soluble solids, fruit firmness, and Hunter values “a” and “b”were increased by the CIS treatment. Flesh browning after peeling the fruit was delayed by the CIS treatment, and polyphenoloxidase (PPO) activities were lowered.

scholarly journals (338) Effect of Germanium Supply by Trunk Injection on Tree Growth and Fruit Quality of `Niitaka' Asian Pear (Pyrus pyrifolia)

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1084A-1084
Author(s):  
Wol-Soo Kim ◽  
Jung-An Jo
Keyword(s):  
Foliar Application ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Pyrus Pyrifolia ◽  
Fruit Firmness ◽  
Asian Pear ◽  
Trunk Injection ◽  
Pear Trees ◽  
Flesh Browning

Many trials to supply germanium to fruit have been carried out since tests have confirmed germanium's role as a medical substance. Supplying germanium in orchards by soil and foliar application was not effective because of loss from rainfall. In order to increase germanium absorption by fruit, this study carried out tree trunk injections during the growing season. Two types of germanium, GeO (inorganic type) and Ge-132 (organic type), in concentrations of 5, 10, 25, and 50 mg·L–1 were supplied to `Niitaka' pear trees by trunk injection (1.5 L/tree), four times at 15-day intervals from June 2004. The treatment with 50 mg·L–1 GeO showed decreased fruit weight, but 50 mg·L–1 Ge-132 showed no difference to the control and other treatments. Fruit lenticels were increased in size by all of the Ge treatments in comparison to control fruit. Soluble solids as well as Hunter value `a' of the fruits of all Ge treatments were higher than that of the control. Flesh browning after peeling the fruit was delayed by the germanium treatment, and polyphenoloxidase (PPO) activities were lowered. Postharvest potentials were maintained at high levels for fruit firmness, physiological disorders, and decayed fruit during cold storage at 0 to 1 °C for 2 months.

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