Genetic diversity and differentiation of Camellia sinensis L. (cultivated tea) and its wild relatives in Yunnan province of China, revealed by morphology, biochemistry and allozyme studies

Abstract

Genetic diversity and differentiation of Camellia sinensis L. (cultivated tea) and its wild relatives in Yunnan province of China, revealed by morphology, biochemistry and allozyme studies Abstract We evaluated morphological, isozyme and biochemical diversity of a total of 87 accessions in the genus Camellia [Camellia sinensis var. sinensis (10), C. talinensis (7), C. sinensis var. dehungensis (3), C. crassicolumna (3) and C. sinensis var. assamica (64)]. Great variation of morphological characters was apparent within each taxa. Across the five taxa, all leaf and most flower quantitative characters showed significant differences while all fruit quantitative characters measured did not differ significantly, and, seven (i.e., life form, bud color, petal texture, pubescence on ovary, style number, stamen location and locule per fruit) of the 33 qualitative characters yield significant differences. As a whole, caffeine content had the highest variation with CV of 22.7%, water extract solid showed the least variation (13.4%) and content of polyphenols (20.0%) and free amino acids (18.8%) showed intermediate variations. Camellia taliensis and C. sinensis var. assamica had significantly higher content of polyphenols and water extract solid than in the other three taxa, while no significant differences were detected for the content of caffeine and free amino acids. For allozyme study, 14 loci presented good resolution, among which, nine loci (64%) were polymorphic in each taxon (AAT-3, FUM-1, 6PDG-1, G6PDH-1, G3PDH-1, ME-1, PGM-1, PGM-2 and SKD-1). The percentage of polymorphic loci (P) for each taxon was 21.4-50.0%. Mean heterozygosity per locus (H e ) varied 0.114-0.218. F ST value indicated that only 4.6% of the variations could be ascribable to genetic differences among taxa. Genetic relationships among the five taxa revealed by allozymes, were also exposed by the result of clustering of the morphological and biochemical characters.

Genetic diversity and differentiation in Camellia reticulata (Theaceae) polyploid complex revealed by ISSR and ploidy

“…at the species level; mean PPB was 21.4-50%, and mean I was 0.229 at the population level (Kaundun et al, 2000;Kumar, 2002;Chen et al, 2005;Thomas et al, 2006). In the present study, PPB was 88.89%, H was 0.2809, and I was 0.4278 at the species level; mean PPB was 42.12%, mean H was 0.1373, and I was 0.2058 at population level.…”

Worldwide core collections of tea (Camellia sinensis) based on SSR markers

“…Floral morphology is useful for the analysis of genetic relationships because of its high heritability, and has been used to evaluate relationships among genetic backgrounds in C. sinensis (Takeda and Toyao 1980;Toyao and Takeda 1999;Chen et al 2005). Therefore, we evaluated each accession for density of pubescence of the ovary, level of style protrusion, number of split style segments, depth of style splitting, and extent of style bending.…”

Diversity distribution and population structure of tea germplasms in China revealed by EST-SSR markers

“…In Yunnan province, the investigation of wild tea plants revealed that high degree of variation in plant height (1.2-26.5 m), leave size (6.9-25.3 cm), flower size (1.7-8.6 cm), fruit size (1.2-6.6 cm), petal number (4-16), ovary locules (3-5), and style splitting (3-7;Yu 1986). And great variations were also found on morphology, biochemistry, and allozymic loci among cultivated tea and its wild relatives (Chen et al 2005a). In our study, a majority of rare SSR alleles and higher diversity were observed in Yunnan and its neighboring provinces, such as Guangxi and Guizhou.…”