Rucheng Baimaocha (Camellia sinensis var. pubilimba Chang) is one of the four tea plants native to Hunan Province, China. Previous studies have shown that Rucheng Baimaocha is different from other three local population resources in Hunan in evolutionary status, and has distinctive characteristics in botanical characteristics, biochemical components and tea making quality. However, there are few studies on the differences of secondary metabolites of Rucheng Baimaocha germplasm resources. Using UPLC-MS/MS analysis technology, taking Anhua population (AHQT, C. sinensis var. sinensis), Chengbu Dongcha [CBDC, C. sinensis var. assamica (Masters) Kitamura], and Jianghua Kucha [JHKC, C. sinensis var. assamica (Masters) Kitamura] of typical local tea resources in Hunan as controls, the significantly different metabolites in Rucheng Baimaocha were screened and clustered by K-means analysis and differential metabolite enrichment pathway analysis. Compared with the control, 189, 180 and 162 significantly different metabolites were screened in Rucheng Baimaotea, the most species were flavonoids (69, 51 and 60 respectively), followed by phenolic acids (31, 40 and 25 respectively), and the least were lignans and coumarins (5, 4 and 4 respectively). Compared with the other three populations, Rucheng Baimaotea increased the content of 15 metabolites. The content of flavonoids and phenolic acids increased the most in Rucheng Baimaocha, and the highest increase was pinocembrin, followed by 1,2,3,6-tetra-o-galloyl-d-glucose. The differential metabolites were analyzed by K-means clustering. The metabolites with the same change trend in the four groups could be divided into nine categories. Among the four populations, there were 32 metabolites with the same change trend and the highest content in Rucheng Baimaotea, mainly flavonoids and tannins. The results of KEGG pathway enrichment of differential metabolites showed that the differential metabolites of Rucheng Baimaotea were mainly enriched in flavonoid biosynthesis pathway, flavonoid and flavonol biosynthesis pathway, phenylpropane biosynthesis pathway and so on. In addition to the differential metabolites reported in some tea, some differential metabolites less concerned in tea research were detected, such as pinocembrin, ellagic acid, kaempferol, etc. The substances would provide an important reference for the excavation and breeding of characteristic tea germplasm resources of Rucheng white tea in the later stage.

In order to determine the quality of soil fertility of bamboo species in coastal sandy land and guide the construction and management of bamboo shelter forest in coastal sandy land, the difference of soil physical and chemical properties of different bamboo forests in coastal sandy land and evaluate the soil quality were studied. Eight bamboo species in coastal sandy land were selected from Chishan State-owned Farm in Dongshan County, Fujian Province. The physical and chemical properties of the 0-20 cm soil layer of each bamboo species were determined. One-way ANOVA analysis was conducted to test the significance of each index, and principal component analysis weighted comprehensive index method and fuzzy mathematics were used to comprehensively evaluate the soil fertility quality of different bamboo species. Soil moisture content, soil density, capillary porosity, non-capillary porosity and total soil porosity of Oligostachyum lubricum were significantly different from those of other bamboo forest (P<0.05). The average pH of soil ranged from 5.01 to 7.36, and there was no significant difference in the pH of other bamboo forests except the neutral soil pH of Bambusa oldhamii (P>0.05). The average soil organic from 4.43-11.06 g/kg, Pseudosasa amabilis var. convexa was significantly lower than that of other bamboo forests. The average range of soil total potassium and available potassium was 4.59-79.33 g/kg and 0.78-43.11 mg/kg. The average range of soil total nitrogen and total phosphorus was 0.47-2.42 g/kg and 0.09-0.37 g/kg, and soil electrical conductivity, total availability and quick availability of N, P, K. had significant differences among different bamboo forests (P<0.05). The order of soil fertility quality index order of the eight bamboo species was P. japonica>O. lubricum>Phyllostachys nidularia f. farcata>B. oldhamii>Dendrocalamus minor var. amoenus>B. tuldoides 'Swollenintrnode'>B. eutuldoides var. viridi-vittata>P. amabilis var. convexa. The physical and chemical properties and total soil quality of bamboo shelterbelt in coastal sandy land were significantly affected by the types of bamboo stands. P. japonica could effectively improve soil quality, but the effect of P. amabilis var. convexa. on soil improvement was not obvious. Bamboo species and planting methods should be selected rationally for the construction and management of bamboo shelterbelt in coastal sandy land.

This article aims to study the differences in the photosynthetic characteristics of different tea cultivars. The photosynthetic parameters in the leaves of nine tea cultivars were determined under field conditions, and the light response curves were drawn. The photosynthetic indicators of different tea cultivars were comprehensively evaluated by statistical analysis, principal component analysis, cluster, discrimination analysis and correlation analysis. There were great differences in net photosynthesis rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), intercellular CO₂ concentration (C_i). Among them, P_n, T_r of 'Yunshan' and 'Yunkang 10^#' were significantly higher than those of the other tea cultivars (P<0.05), G_s of 'Tian', 'Baohong' and 'Shilixiang' was significantly lower than that of the other tea cultivars (P<0.05), C_i of 'Changningdayezhong' was significantly lower than that of the other tea cultivars (P<0.05). At the beginning of photosynthetically active radiation (PAR), differences in the P_n between tea cultivars were not distinct. However, with the increase in PAR, great differences in P_n between tea cultivars appeared. The G_s and T_r of the nine tea cultivars showed two trends with the increase of PAR, 'Xiangguiyinhao' showing a first upward and then trend till to be stable, while other tea cultivars showing an overall upward trend. The C_i of the nine tea cultivars decreased rapidly at first and then tended to be stable. The WUE and iWUE increased first and then decreased with the increase of PAR, and the ability to tolerance of strong drought for 'Changningdayezhong' and 'Xiangguiyinhao' was better than that of the other tea cultivars with a higher WUE and iWUE, and both of them could be used as the drought tolerance tea cultivars suitable for breeding needs. The photosynthetic potential for 'Yunkang 10^#', 'Xiangguiyinhao', 'Yunashan' was better than the other tea cultivars with a higher P_nmax, and they could be used as the high-light-efficiency tea cultivars suitable for breeding needs. The LSP of 'Shilixiang', 'Changningdayezhong' and 'Zijuan' was significantly higher than that of other tea cultivars (P<0.05), and had a strong ability to use strong light. The strong ability to use low light for 'Xiangguiyinhao' and 'Shilixiang' was better than that of the other tea cultivars with a lower LCP (P<0.05). The nine tea cultivars were divided into four groups by principal components and cluster analysis. Correlation analysis indicated that P_n was significantly positively correlated with G_s and T_r (P<0.01).