Screening Tea Germplasms With Early-sprouting, High Quality And Specific Traits And Analysis Of Their RAPD Markers

Production of Chinese famous teas and development of functional components separated from tea play more and more important role in tea industry. Production practice showed that the famous teas production depended on two key factors, i.e. tea cultivars and the production stage in the Spring. Functional components extracted from tea are now widely used in medicines and functional food productions and their demand are increasing. The important targets of tea breeding are now to breed cultivars with characteristics of early sprouting, high quality and containing high concentration of tea polyphenols or catechins and lower concentration of caffeine. .In the present study, chemical composition of twelve tea lines were compared and identified. Genetic diversity were tested with RAPD method and DNA molecular markers linked to economic traits of tea plants were investigated.(1) Sprouting stages and chemical compositions of 12 tea germplasms were investigated. The results showed that the lines JP-1, JP-3, J-2 and J-3 had characteristics of early sprouting, high concentrations of tea polyphenols, amino acids and caffeine, which were suitable for breeding quality green tea cultivars. The lines J-1,J-2 andJP-4 had lower content of caffeine, which might be good germplasms for breeding low caffeine tea cultivars. The lines S-1 and S-2 had high concentration of tea catechins and were good materials for breeding cultivars with high concentration of catechins.(2) The diversity of 12 tea germplasms were tested with RAPD and it showed that they could be classified into 3 groups. The lines JP1 ～4 introduced from Japan and 'Fudingdabaicha', 'Wuniuzao' and 'Zhenong139' had close genetic distance and were classified as group 1. The group 2 had 3 lines, i.e. lines JP-1, JP-2 and JP-3. The lines S-l and S-2 introduced from Sanmen County of Zhejiang Province were classified into group 3.(3) Twelve lines which were introduced from various estates and had various concentrations of caffeine, were investigated by RAPD technology, in which 16 molecular markers specifically amplified on single lines were identified and the molecular markers could be used as indicators identifying related tea cultivars or lines. Some of the specific loci were sequenced, for example the band S43.04 had 752 bps with a reading frame encoding 40 amino acids. The amino acids sequence had 72% identity with the gene encoding β -galactosidase.