Study On Germplasm Resources Of Wild Yingjing Loquat Tea Plants

Wild Yingjing loquat tea plants were precious and rare varieties which mainly distributed in Yingjing county of Sichuan province and had rich genetic background. Tea tree, leaves, flowers and fruits were studied preliminarily by investigation. Many representational and specific wild plants had been screen out in the study. This paper selected five different types of loquat tea plants which were numbered as Ⅰ-Class, Ⅱ-Class, Ⅲ-Class, Ⅳ-Class, Ⅴ-Class for studying by the tree and tip which are the first principal component analysis and great contribution; the number of petals, style split, vein logarithmic and serrated as the second. The paper mainly studied botanica and biological characteristics, leaf anatomical structure, major biochemical components, productive characteristic and karyotype on Yingjing loquat tea. The main results as follows:(1)Wild Yingjing loquat tea plants mainly distributed in the natural communities of N29°50.783’～N29°50.947′、E102°49.374′～E102°49.579′,923-1146m above sea level. There are rich in resources and types of complex genetic variation. This paper observed the determination of the botanical characteristics of five types (morphology, phenological phase and growth, leaf anatomical structure, etc.). The results showed that Yingjing loquat tea plants had the following characteristics:mostly trees, large leathery leaves and elliptic, fat shoots and low density, large flowers, stigma split number of2to5crack, numerous hairs of ovary, pistil was higher than stamens, hard fruit and thicker pericarp, subreniform seeds. It preliminarily judged that the Yingjing loquat tea belonged to C.taliensis Melch of Tianlu Min classification systems by tree, tip, ovary hairy, leaves anatomical structure. Different types of tea plants have different botanical characteristics. Through the appraisal, the study found that Ⅱ-Class were original compare with other tea plants, Ⅳ-Class and Ⅴ-Class had some extent evolution and lots of tea plants belonged to traditionally type. The resistance of Ⅲ-Class were strongest from analyzing leaf anatomy.(2) This paper observed main biochemical composition of spring, summer and autumn shoot and the sensory evaluation of black tea and green tea. The results showed there were some differences in biochemical composition and content of different types of Yingjing loquat tea plants.The content range of free amino acids was2.99±0.11%～4.45±0.16%, tea polyphenolcontent range was25.18±4.43%～35.75±0.52%, caffeine content range was3.11±0.01%～4.48±0.04%,water extract content range was37.02±6.06%～44.94±3.40%, total catechins content range was90.78±7.28mg/g～158.28±4.03mg/g, ratio of polyphenol to amino acid was5.85～9.87. According to the content of biochemical components, ratio of polyphenol to amino acid and sensory evaluation, IV-Class were appropriate for making green tea which had high quality index of catechins and total amino acid content; Ⅲ-Class and Ⅴ-Class were appropriate for making black tea which had high content of tea polyphenol in summer and autumn. Some types of Yingjing loquat tea plants can be used as basic material for black tea or breeding materials which have high content of tea polyphenol.(3) This experiment used root as the tested materials, which adopted the degradation of wall and hypotonic method to analyze karyotype. The results showed that chromosomes of five different types showed morphological diversity and belonged to medium and small chromosomes, karyotype formulas were2n=2x=30=22m+8sm, these belonged to the original type2A as the Stebbins standard. According to an average arm, the ratio of the longest chromosome to the shortest chromosome, the symmetry of karyotype and the asymmetry index of karyotype, Ⅲ-Class were more primitive types, IV-Class and V-Class were relative evolution. According to the theory of Stebbins, the direction of karyotype evolution is symmetry to asymmetry in the evolutionary process, so wild Yingjing loquat tea plants is changing from the type of original to the type of evolution.(4) Wild Yingjing loquat tea plants have changed continuously and gradually from the wild type to cultivated type in morphological characters and genetic basis. These tea plants appear abundant diversities.