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Volume 2007, Issue 104
Displaying 1-9 of 9 articles from this issue
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Hirofumi Nagatomo, Kenichiro Sato, Kunihiko Sato, Tsuruyoshi Furuno, S ...2007 Volume 2007 Issue 104 Pages 1-14
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSA new cultivar 'Yumekaori' for green tea was bred at the Tea Branch Facility, Miyazaki Agricultural Research Institute and registered as Cha Norin No.54 by the Ministry of Agriculture, Forestry and Fisheries in October, 2006. This cultivar was selected out of seedlings crossed between 'Sayamakaori' and 'Miyazaki No.8' in 1986. 'Yumekaori' is the first cultivar in Japan which was bred for the resistance to Pseudaulacaspis pentagona (Targioni-Tozetti).
The characteristics of this cultivar are as follows ;
This cultivar is early budding, the plucking time of the 1st crop is about 4 days earlier than in 'Yabukita'. The shape of the plant is intermediate type and the growth is slightly vigorous.
This cultivar is slightly susceptible to tea anthracnose (Colletotrichum theae-sinensis (Miyake)Yamamoto) and tea blister blight (Exobasidium vexans Massee). But it is fairly resistant to tea gray blight (Pestalotiopsis longiseta Spegazzini). This cultivar is more resistant to P pentagona than 'Sayamakaori'.
It is fairly resistant both to cold damage in midwinter and to bark split frost injury in early winter. The yield of green leaves of this cultivar is higher than that of 'Yabukita'. The quality of processed tea is very good, the aroma is fresh and the taste is body.View full abstractDownload PDF (1979K) -
Tomomi Ujihara, Nobuyuki Hayashi, Katsunori Kohata, Satoru Matsushita, ...2007 Volume 2007 Issue 104 Pages 15-23
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSIn order to reveal intraspecific variation in the tea (Camellia sinensis), the nucleotide sequence of the rbcL-accD region in the chloroplast genome of 21 Japanese tea cultivars, 22 and 7 tea clones collected in China and Vietnam, respectively, and 6 Chinese cultivars were determined. The nucleotide sequence was well conserved. Eighteen Japanese tea cultivars selected from local varieties were divided into 2 types based on 2 SNPs (Single Nucleotide Polymorphisms). One of these types (Ia) was mainly distributed in Kyoto. Both types were also found in the Asian continent, indicating that they were derived from there to Japan. Twelve additional types were found in tea of the Asian continent. Some of the tea clones from south China had one or two of the three In/Dels (insertion/deletion polymorphism), which are unique in C. taliensis and C. irrawadiensis. Chloroplast DNA can be used in order to distinguish genetic background of the cultivars of tea leaves on the market.View full abstractDownload PDF (504K) -
Kengo Yamada2007 Volume 2007 Issue 104 Pages 25-32
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSTea phylloplane fungi were screened for antagonism to the tea anthracnose fungus, Colletotrichum theae-sinensis. Penicillium, Sporothrix and two unidentified species were screened by dual-culture test. Cultural filtrate of Penicillium and Sporothrix inhibited elongation of germ tube of conidia of C. theae-sinensis. But only Sporothrix suppressed lesion size of anthracnose by 65-50% in wound-inoculation experiments using detached tea leaves. In field experiments, spraying of conidial suspension of Sporothrix did not decreased the number of anthracnose diseased leaves. It was able to isolate Sporothrix selectively from tea leaves by the medium amended with cycloheximide 50mg/L and chloramphenicol 100mg/L. Population densities of Sporothrix from tea leaf surface were approximately 102-103 cfu/cm2 when plating leaf washings onto the selective medium. Sporothrix was not isolated when leaf surfaces were sterilized with sodium hypochlorite solution. By microscopic observation, Sporothrix colonized and sporulated on trichomes of tea leaves. These results suggest that Sporothrix is epiphytic resident, not endophytic or casual on tea leaves.View full abstractDownload PDF (2642K) -
Kunihiko Satoh2007 Volume 2007 Issue 104 Pages 33-42
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSHatchability of Pseudaulacaspis pentagona (Hemiptera: Diaspididae) was investigated under a high humidity (relative humidity was 100%) and submerged conditions in the laboratory. After eggs had experienced 7 days of the high humidity and submerged conditions, the hatchability dropped to 20 and 7% under a suitable condition (70% in relative humidity) for hatching, respectively. No larvae were found after keeping the submerged condition for 10 days. A control method of high humidity conditions against P. pentagona eggs beneath their mother's scale was tested using a sprinkler in tea fields. Tea branches were always wet by the intermittently sprinkling water (120 to 150t/ha per day) during day time and P pentagona eggs discolored and died under mother's scale. The high humidity conditions using the sprinkler for 16 days after initiated the first hatching of P. pentagona eggs gave effective control against P. pentagona in tea fields.View full abstractDownload PDF (1787K) -
Mari Maeda Yamamoto, Asuka Maehara, Kaori Ema, Yuzo Mizukami, Fumiko K ...2007 Volume 2007 Issue 104 Pages 43-50
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSTo clarify the suitable extraction method of 'benifuuki' green tea containing O-methylated catechins having anti-allergic action, the extraction rate of O-methylated catechins was examined under various extracion conditions.
To elute more than 60% of 0-methylated catechins from 'benifuuki' green tea leaf, the extraction more than 5 minutes in boiling water was necessary. The elution rates were approximately 30% after extraction in hot water for five minutes, and only 14% after overnight in a cold water. So, to consume 34mg (efficient amount for the symptom improvement of the perennial nasal inflammation) of epigallocatechin-3-O- (3-O-methyl)-gallate a day, we should consider the quantity of tea leaf and extraction time.
The concentration of pheophorbide-a (PBa; that is responsible for photosensitivity dermatitis) in tea leaves was measured after soaking 'benifuuki' green tea powder, a common selling form, in warm water for a long time. PBa of 80mg/100g was produced after incubation of green tea (first crop season, younger shoot, 30 seconds steamed) in warm water of 40 C for three hours. The production of PBa in second crop tea was very few. It was suggested that it is better to avoid to soaking 'benifuuki' green tea powder in warm water for a long time.View full abstractDownload PDF (475K) -
Tsuyoshi Okamoto, Takaaki Orita, Yutaka Uezono, Susumu Hanashiro, Kish ...2007 Volume 2007 Issue 104 Pages 51-65
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThere were a number of serious and widespread salty wind damage to tea fields in the southern-coastal part of Kagoshima and Okinawa Prefectures in 2004 due to five typhoons.
We have researched to farmers tea fields, and found that sorghum intercropping in everyother-row (1.8m interval) made it possible to minimize damage, while intercropping in every second (3.6m interval) or third (5.4m interval) row was considerably less effective.
A number of severe damages arised even two years after planting because of no sorghum intercropping. It was saved from death of tea plants in the cases of doing sorghum intercropping in the tea field two years after planting. In typhoon-prone regions, sorghum intercropping must be continued in the second year in newly planted tea fields.View full abstractDownload PDF (4927K) -
Yukio Kosugi2007 Volume 2007 Issue 104 Pages 67-72
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSWe conducted a questionnaire survey with the technical adviser of the farm co-operative and farmers for assessing the occurrence of Green Flatid planthopper Geisha distinctissima (Walker) in tea fields. The survey distinctly revealed that the planthopper was present throughout the Shizuoka prefecture. It is believed that the population of G. distinctissima has increased during these past several years.
Among the 7 insecticides investigated, DMTP was the most effective pesticide against the nymphs and adults of this planthopper, irrespective of the disposal method.View full abstractDownload PDF (323K) -
2007 Volume 2007 Issue 104 Pages 73-78
Published: December 31, 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (289K) -
2007 Volume 2007 Issue 104 Pages e1
Published: 2007
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (84K)
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