Morphological and Molecular Differences of Exobasidium vexans Massee Causing Blister Blight Disease of Tea

D.C. Abeysinghe,K.M. Mewan,W.M.S.S. Kumari,K.L.W. Kumara 한국차학회 2015 한국차학회지 Vol.- No.S

Tea Blister blight, which is caused by Exobasidium vexans Massee is the most serious tea leaf disease in Sri Lanka. The disease is primarily controlled by fungicidal sprays. Continuous application of fungicides can contribute to the development of new races/strains. Therefore, current study was conducted to identify morphological and genetical variation of E. vexans. Infected leaf samples collected from quite apart and geographically more diverse regions representing Kandy, Passara, and Talawakele in Sri Lanka were analyzed for morphological parameters such as length and width of spores. DNA extracted from spores, which were collected from mature blisters of different samples, was assessed by RAPD-PCR to identify molecular differences. Statistical analysis was performed using SAS statistical software package. Significant differences were obtained for length and width of E. vexans spores of different isolates. In the liquid media tested, sucrose and lactose solutions were found to be better for the germ tube elongation, than the rest. RAPD-PCR based characterization affirmed genetical variation of E. vexans among the different climatic regions and also among the four cultivars tested.

Effect of Dhool Temperature on Quality of Orthodox Rotorvane Tea and Its Grade Outturn Percentage Manufactured using Two End-Attachments in Different Degrees of Wither

D.C. Abeysinghe,W.S. Botheju,D.P.K.R. Delgamuwa 한국차학회 2015 한국차학회지 Vol.- No.S

Total antioxidant capacities of green tea, oolong tea and black tea processed from the leaves of four selected tea cultivars i.e. TRI 2025, TRI 777, CY 9 and DT 1 were measured by DPPH assay. Colorimetric Folin-Ciocalteu method was used to determine total phenolics. Catechins and caffeine were identified by HPLC. Significantly higher total phenolic contents and catechins were found in green tea produced from all selected cultivars. Green tea and oolong tea had significantly higher total antioxidant capacities than black tea in all selected cultivars except TRI 777 with highest total antioxidant capacity in green tea. In black tea and oolong tea, cultivar TRI 777 showed significant lowest antioxidant capacity when compared to other selected cultivars. The total antioxidant capacity values were positively correlated with the total phenolics (R2 = 0.78), ECG% (R2 = 0.86), EGC% (R2 = 0.71) and EGCG% (R2 = 0.79). Our results indicate that green tea contains higher amounts of total phenolics, catechins (ECG, EGC, and EGCG) and total antioxidant capacities than oolong and black tea produced from all selected cultivars. Phenolics constituents in made tea are the major contributors to the total antioxidant capacity and made tea with high catechins are good sources of dietary antioxidants.

Phenolic Constituents, Caffeine and Antioxidant Capacities in Green, Oolong and Black Tea Processed from Tender Leaves of Four Cultivars Grown in Sri Lanka

D.C. Abeysinghe,A.M.T. Amarakoon,M.A.K. Jayathilake 한국차학회 2015 한국차학회지 Vol.- No.S

Total antioxidant capacities of green tea, oolong tea and black tea processed from the leaves of four selected tea cultivars i.e. TRI 2025, TRI 777, CY 9 and DT 1 were measured by DPPH assay. Colorimetric Folin-Ciocalteu method was used to determine total phenolics. Catechins and caffeine were identified by HPLC. Significantly higher total phenolic contents and catechins were found in green tea produced from all selected cultivars. Green tea and oolong tea had significantly higher total antioxidant capacities than black tea in all selected cultivars except TRI 777 with highest total antioxidant capacity in green tea. In black tea and oolong tea, cultivar TRI 777 showed significant lowest antioxidant capacity when compared to other selected cultivars. The total antioxidant capacity values were positively correlated with the total phenolics (R2 = 0.78), ECG% (R2 = 0.86), EGC% (R2 = 0.71) and EGCG% (R2 = 0.79). Our results indicate that green tea contains higher amounts of total phenolics, catechins (ECG, EGC, and EGCG) and total antioxidant capacities than oolong and black tea produced from all selected cultivars. Phenolics constituents in made tea are the major contributors to the total antioxidant capacity and made tea with high catechins are good sources of dietary antioxidants.

Current Status and Major Challenges of the Tea Industry in Sri Lanka

R,Rajadurai,D,C,Abeysinghe,Y,S,Yoo 한국차학회 2019 한국차학회지 Vol.25 No.2

스리랑카의 차 산업은 스리랑카 경제 전체의 중요한 요소이다. 차 산업은 두 번째로 큰 농업 산업으로 국내 총생산에 크게 기여하고 있으며 100 만 명이 넘는 사람을 직간접적으로 고용하고 있는 국가 최대의 고용주이다. 스리랑카는 세계 차 생산 부문에서 세계 4위를 차지하고 있으며, 세계에서 가장 높은 차 경매 평균가격을 유지하고 있다. 차 산업은 수출 지향적으로 생산되는 차의 97%를 수출하고 있다. 전체 차 생산량의 경우 소규모 소유주들이 70% 이상 기여하며 나머지는 지역 농장 재배지 회사들이 기여하고 있다. 150년이 넘는 오랜 기간에 걸쳐 개발된 차 산업은 1971년과 1975년에 사회주의 개혁의 일환으로 국영화 되었다. 지난 20년 동안 스리랑카 차 산업은 큰 변화를 겪어 왔으며 현재 수많은 문제를 직면하고 있다. 주요 3대 홍차 수출국 (인디아, 케냐, 스리랑카) 중 생산비가 가장 높은 수준이며 단위면적 당 수확량은 가장 낮은 수준이다. 본 논문은 스리랑카 차 산업이 직면한 현황과 과제를 논의함으로써 미래의 지속적인 발전을 이루는 것을 목적으로 한다. Sri Lanka’s tea industry has always been a vital component of Sri Lanka’s overall economy. It significantly contributes to the country’s gross domestic product as the second largest agricultural industry. Sri Lanka’s tea industry is the country’s largest employer and it provided employment both directly and indirectly to over one million people. Sri Lanka is positioned 4th in the world’s tea production and Sri Lanka continues to maintain the highest world auction average price for tea. The tea industry is highly export-oriented with almost 97% of its tea being exported. Small holders contribute more than 70% of the total tea production, and the rest is largely contributed by regional processing companies. Initially developed over a period of one hundred and fifty years, the tea plantation sector was nationalized in 1972 and 1975 as part of socialist reforms. During the last two decades, the industry has undergone major changes and the industry faces a number of significant challenges. The cost of production in Sri Lanka continues to be the highest and the yield per area is the lowest among the three major tea exporting countries (India, Kenya and Sri Lanka). This paper discusses the current status and challenges faced by the Sri Lanka tea industry to ensure that it sustains continued development in the future.

Current Status and Major Challenges of the Tea Industry in Sri Lanka

R. Rajadurai,D.C. Abeysinghe,유양석 한국차학회 2019 한국차학회지 Vol.25 No.2

Sri Lanka’s tea industry has always been a vital component of Sri Lanka’s overall economy. It significantly contributes to the country’s gross domestic product as the second largest agricultural industry. Sri Lanka’s tea industry is the country’s largest employer and it provided employment both directly and indirectly to over one million people. Sri Lanka is positioned 4th in the world’s tea production and Sri Lanka continues to maintain the highest world auction average price for tea. The tea industry is highly export-oriented with almost 97% of its tea being exported. Small holders contribute more than 70% of the total tea production, and the rest is largely contributed by regional processing companies. Initially developed over a period of one hundred and fifty years, the tea plantation sector was nationalized in 1972 and 1975 as part of socialist reforms. During the last two decades, the industry has undergone major changes and the industry faces a number of significant challenges. The cost of production in Sri Lanka continues to be the highest and the yield per area is the lowest among the three major tea exporting countries (India, Kenya and Sri Lanka). This paper discusses the current status and challenges faced by the Sri Lanka tea industry to ensure that it sustains continued development in the future.