scholarly journals Cold Tolerance in 'Kousui' Japanese Pear and Possibility for Avoiding Frost Injury by Treatment with n-Propyl Dihydrojasmonate

HortScience ◽  
2003 ◽  
Vol 38 (2) ◽  
pp. 288-292 ◽  
Author(s):  
Yoshihiko Sekozawa ◽  
Sumiko Sugaya ◽  
Hiroshi Gemma ◽  
Shuichi Iwahori
Keyword(s):  
Free Amino ◽  
Sugar Content ◽  
Japanese Pear ◽  
Pyrus Pyrifolia ◽  
Ion Leakage ◽  
Full Bloom ◽  
Solute Content ◽  
Spring Frost ◽  
Injury Index ◽  
Frost Injury

Effects of n-propyl dihydrojasmonate (PDJ) treatment on flowers of Japanese pear 'Kousui' (Pyrus pyrifolia Nakai cv. Kousui) during spring frost were investigated to study mechanisms for avoiding spring frost injury. PDJ applied during the flowering period resulted in a lower injury index for the ovules and pistils after freezing tests. Average ion leakage in control flowers was 37.9% during the balloon stage at -5 °C, while the flowers treated with PDJ displayed a 16.6% ion leakage. Similarly, at the full bloom stage, PDJ treatment reduced ion leakage at -5 °C from 73.1% to 47.8% in the control. The organs of the flower more sensitive to low temperature stress were the ovule, pistil, and ovary; stamens were more resistant. Sugar content in the flower at the balloon stage was increased by PDJ when treated at the pink stage. Moreover, free amino acids, especially proline, increased similarly with PDJ treatment. These results show that PDJ affects supercooling capacity of a flower by changing solute content and protects organs from freezing.

Effects of wall inhibitors on thymineless Streptococcus faecalis

1974 ◽  
Vol 20 (8) ◽  
pp. 1185-1187 ◽  
Author(s):  
J. G. Bisaillon ◽  
J. de Repentigny ◽  
L. G. Mathieu
Keyword(s):  
Free Amino ◽  
Death Rate ◽  
Sugar Content ◽  
Amino Sugar ◽  
Streptococcus Faecalis ◽  
Inhibition Of Growth ◽  
Thymineless Death

Thymine-requiring (thy−) mutants of Streptococcus faecalis and S. faecalis var. zymogenes were isolated by selection with aminopterin. D-Cycloserine increased the thymineless death rate of a S. faecalis thy− strain, whereas bacitracin, penicillin, and vancomycin decreased it. A S. faecalis var. zymogenes thy− strain behaved similarly, except that penicillin increased its thymineless death rate. D-Alanine reversed the effect of D-cycloserine on both strains. Because of the specificity of the inhibition, our observations suggest that mucopeptide synthesis occurs in S. faecalis not only during growth but also during thymineless death. The variations in free amino sugar content resulting from D-cycloserine inhibition of growth and thymineless death also support this conclusion.

scholarly journals Spring frost effects on 30 sweet cherries varieties grown in North Italy

2010 ◽  
Vol 16 (4) ◽  
Author(s):  
A. Roversi ◽  
E. Pattori ◽  
G. L. Malvicini ◽  
S. Sbaruffati
Keyword(s):  
Sweet Cherry ◽  
Frost Damage ◽  
Flowering Stage ◽  
Full Bloom ◽  
Absolute Minimum ◽  
Spring Frost ◽  
Sweet Cherries ◽  
Fruit Harvest

After a spring frost occurred in second half of March 2008, with temperatures below 0°C for 8 days consecutively and an absolute minimum of -5.5°C, a lot of observations have been made on the sweet cherry flowers damages. In three different orchards “Italian palmetta” trained on grassing ground soil, the percentage of the flowers killed by frost, was detected and recorded considering the different genotypes and flowers height from the ground. Furthermore, in one orchard only it was possible to find relationship between flowering stage and frost damage. The results clearly confirm our previous works about the highest mortality of the flower in the upper part ( > 1.50 m) of the canopy and in the full bloom open flowers. So, in this area, the easiness of agronomic operations, like pruning and, especially, fruit harvest, due to the crown proximity to the ground, is cancelled by the frequency of spring frost.

scholarly journals Cloning of the S8-RNase (S8-allele) of Japanese Pear (Pyrus pyrifolia Nakai).

2002 ◽  
Vol 19 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Carlos CASTILLO ◽  
Takeshi TAKASAKI ◽  
Toshihiro SAITO ◽  
Shigemi NORIOKA ◽  
Tetsu NAKANISHI
Keyword(s):  
Japanese Pear ◽  
Pyrus Pyrifolia ◽  
Pyrus Pyrifolia Nakai

Botryosphaeria berengeriana f.sp. piricola. [Distribution map].

1996 ◽  
Author(s):  
Keyword(s):  
Geographical Distribution ◽  
Japanese Pear ◽  
Pyrus Pyrifolia ◽  
Malus Pumila ◽  
Distribution Map ◽  
European Pear ◽  
New Distribution

Abstract A new distribution map is provided for Botryosphaeria berengeriana f.sp. piricola (Nose) Koganezawa & Sakuma. Hosts: Japanese pear (Pyrus pyrifolia), also European pear (P. communis) and apple (Malus pumila). Information is given on the geographical distribution in China, Anhui, Fujian, Guangxi, Hebei, Henan, Hubei, Jiangsu, Jiangxi, Jilin, Liaoning, Shandong, Shanxi, Sichuan, Zhejiang, Japan, Honshu, Shikoku, Korea Dem. People's Republic, Korea Republic, Taiwan.

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.

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