Sugarcane is an important sugar crop in the world, but the main sugarcane producing areas in China are hilly and dry slopes, and seasonal droughts occur frequently due to the uneven distribution of rainfall. Droughts do great harm to yield and quality and the sustainable development of sugarcane industry in China. The plant hormone abscisic acid (ABA) not only regulates plant growth and development, but also plays an important role in the physiological and biochemical responses of plants environmental stresses. In this study, we used sugarcane (Saccharum officinarum L.) variety 'Guitang 42' as the material to investigate the effects of exogenous ABA on leaf physiological characteristics and gene expressions under water stress condition in treatments control (normal irrigation), control+ABA, drought (stop irrigation), drought+ABA. The foliar application of 15 μmol/L ABA was sprayed twice in two days before drought stress given. The results showed that the changes of main physiological and biochemical parameters and gene expression in control+ABA treatment were not significantly different from those of the control. The leaf relative water content (RWC) was gradually decreased by drought treatment but it could maintain higher in drought+ABA treatment. The drought treatment could result in an increase in malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content, but the plants applied with ABA were found to resist the excessive accumulation of MDA. Drought stress significantly reduced the leaf chlorophyll content in sugarcane, but the exogenous ABA application decreased the degradation of chlorophyll, counteracted, at least in part, the decrease in quantum efficiency of PSII (ΦPSII). The expression of gene encoding 9-cis-epoxycarotenoid dioxygenase (NCED) for ABA biosynthesis, the genes encoding Δ1-pyrroline-5-carboxylate synthase (P5CS) for proline biosynthesis, and the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) encoding genes was significantly increased in the leaf under water stress condition, following the significantly higher endogenous ABA content, proline content and CAT, SOD, APX and POD activities in water stress treatment as compared to the control. But exogenous ABA application under water stress could further enhance the expression of the genes, hence further improved the ABA content, proline content and related antioxidant enzyme activity. The results clearly suggests that the foliar ABA application could triggering the over expression of antioxidative defense system, and improve drought tolerance of sugarcane under water stress condition.

The analysis of the genetic diversity of aromatic rice varieties and clarification of the genetic relationship of aromatic rice varieties can provide references for breeding high-quality aromatic rice varieties. 24 conventional aromatic rice varieties approved in Guangxi was used in the study. The genetic diversity of the varieties was analyzed by SSR fluorescence labeled capillary electrophoresis in this study. The results showed that a total of 170 alleles were detected by 48 SSR primers. The number of alleles (Na) varied from 1 to 9, with an average of 3.54. The range of effective allele number (Ne) ranged from 1 to 4.5534, with an average of 2.0736. The highest effective allele number was RM21, followed by RM481, RM493 and RM258. Four pairs of primers had high detection efficiency. Shannon's index (I) ranged from 0 to 1.7942 with an average of 0.7726. The variation range of polymorphic information content (PIC) ranged from 0 to 0.7541 with an average value of 0.3732, indicating that the 24 varieties had certain genetic variation. The genetic similarity coefficient of the 24 varieties ranged from 0.3299 to 0.9600, among which the genetic similarity coefficient of 'Sanxiang 628' and 'Nongxiang 32' was the lowest, indicating that the genetic basis difference of the two varieties was the greatest and the genetic relationship was the furthest. The genetic similarity coefficient of 'Wanxiang 696' and 'Guangliangxiang 2' was the greatest, indicating that the genetic basis difference of the two varieties was small and the genetic relationship was close. Cluster analysis showed that the 24 cultivars could be divided into three large groups and four subgroups at the similarity coefficient of 0.504. There were two varieties in theⅠcategory, 19 varieties in theⅡcategory and 3 varieties in theⅢcategory. CategoryⅡcould be divided into 4 subclasses at the similarity coefficient of 0.624, including 1 variety in Subclassⅰ, 14 varieties in subclass ⅱ, 3 varieties in subclass ⅲ, and 1 variety in subclass ⅳ. The results showed that there was a certain genetic diversity in the 24 varieties, but it was not rich enough. The DNA fingerprints of the 24 varieties were constructed in the form of digital coding. The results could provide references for breeding and identification of conventional aromatic rice varieties in Guangxi.

Identification of heterozygote is a key step in the cross breeding of Lentinula edodes. A new ISSR technique (N-ISSR) was designed in this study based on discrimination between the two nucleus of the donor strain to identify quickly and accurately the authenticity of hybrid strains of L. edodes. The new ISSR was used to identify 40 hybrid strains which were from the Di-mon mating between dikaryon wild strain YX7 and spore monokaryons of cultivated strain 808, as well as microscopy observation combined with antagonistic test (MOCAT) and the traditional ISSR technique (T-ISSR) as the control. N-ISSR results showed 27 strains were confirmed to be true heterozygote as they possessed specific DNA bands from one of the nucleus of donor strain YX7, and the other 13 strains were confirmed to not be heterozygote. Among them, 11 strains were strain YX7 itself as they possessed both specific DNA bands from the two nucleus of strain YX7, and 2 strains were spore monocaryons of strain 808 as they had no any specific DNA bands of donor strain YX7. Compared with MOCAT, N-ISSR could thorough identify all the 27 heterozygote strains, which included the 19 strains identified as heterozygote, the 6 strains unable to be identified and 2 strains incorrectly identified as non-heterozygote by MOCAT. N-ISSR could identify all the 27 heterozyote stains and 13 non-heterozyote stains with simple primer, and could classify the heterozygote strains into two groups according to the type of nucleus received from the donor. On contrast, T-ISSR needed 4 primers to identify all the 27 heterozygote strains, and was unable to con firm the other 13 stains as non-heterozygote stains, and was unable to classify the heterozygote strains into two groups. In conclusion, N-ISSR was an effective tool to be used for fast, extensive and accurate identification of heterozygote and non-heterozygote strains of L. edodes, and would be a technical support for further study on the cross breeding and genetic analysis of L. edodes.

Gynostemma pentaphyllum is an important medicine-food homology plant. It enjoys the reputation of 'Southern ginseng' as it contains compounds of ginsenosides. As wild resources of G. pentaphyllum depleted gradually, artificial introduction and cultivation of G. pentaphyllum has become an inevitable trend. However, due to soil irrigation, fertilization, and pesticide use, problems such as unstable quality of medicinal materials and excessive heavy metal content in G. pentaphyllum occur from time to time, which seriously affects its standardized cultivation and the quality and safety of medicinal materials. Hydroponic production has the advantages of short cycle, high yield, no continuous cropping obstacles, and can effectively avoid heavy metal pollution, so it is widely used in the production of various Chinese medicinal materials. In this study, G. pentaphyllum seedlings were treated with different nutrient solution, temperature, light intensity and photoperiod. After that, growth characteristics and accumulation of total saponins of G. pentaphyllum were examined to obtain the most suitable hydroponics conditions, and thus provide reference and technical support for the large-scale production and organic cultivation of G. pentaphyllum. The results showed that Japanese Yamzaki formula with pH value 6.0 was the best nutrient solution for hydroponics of G. pentaphyllum. Correlation analysis showed that under different nutrient solution conditions, the total saponin content of single plant was highly positively correlated with plant height, leaf length, leaf width, number of leaves, fresh weight per plant and dry weight per plant, indicating that the cultivation of high-biomass plants was the key of the cultivation of high-quality plants of G. pentaphyllum. Under variable temperature of 20 to 30 ℃, photoperiod of 10 to 14 hours of light per day, and light intensity of 100 μmol/(m²·s), seedlings of G. pentaphyllum grew well and the total saponin content of the dry samples exceeded 3%, which was higher than the existing standards. This study would provide a scientific basis for the realization of double precise control of production and quality of G. pentaphyllum, and lay the foundation for the future research on large-scale production and quality standards of it.

Sugarcane is an important sugar crop and energy crop. Evaluating the nutritional quality of sugarcane germplasm resources can systematically understand the nutritional value of sugarcane germplasm resources, and provide scientific basis for the development and utilization of sugarcane germplasm resources and breeding of new varieties. We carried out a study using 100 sugarcane germplasms, analyzed 14 nutritional indexes such as sucrose, reducing sugar, total free amino acid, polyphenol, mineral and protein in sugarcane juice, SPSS software was used for Principal Component Analysis (PCA) and Systematic Cluster Analysis (SCA) of nutritional quality traits. Results showed that there were differences in nutritional components among the 100 sugarcane germplasms and some nutrients had a significant correlation with each other. Sucrose content was negatively correlated with reducing sugar, protein, total free amino acid, fructose and glucose content, while protein content was positively correlated with total free amino acid and total polyphenol content. The content of fructose, glucose and sucrose was positively correlated with the content of P. Among mineral elements, Ca content and Fe content, Fe content and Cu content were positively correlated. The main factors affecting the nutritional quality of sugarcane germplasm were reducing sugar factor, protein factor, sucrose factor, Ca content factor and K content factor. The cumulative variance contribution rate of the common factors to comprehensive evaluation of sugarcane nutritional quality was 69.62%. SCA showed that the nutritional quality of the 100 sugarcane germplasms could be divided into 5 groups (European distance D=18.5). Group Ⅰcontained 77 resources, which had the highest sucrose content. Group Ⅱ contained 6 resources with higher Ca and Fe content. Group Ⅲ contained 2 resources, the average content of reducing sugar, protein, total free amino acid, total polyphenol, fructose, glucose, P, Na was high, and the average sucrose content and Fe content were low. Group Ⅳ contained 4 resources, which had the highest average total free amino acid content, higher average protein and total polyphenol content. Group Ⅴcontained 11 resources, with the highest average K content. The comprehensive evaluation of nutritional quality of the 100 sugarcane germplasms showed that the top 5 sugarcane varieties were 'Hetang 1', 'Dezhe 0978', 'Funong 40-95', 'Zhongzhe 45' and 'Yunzhe 06-193'.

Low-ammonia concentrated natural rubber latex (CNRL) can alleviate the ammonia contamination problem caused by high-ammonia CNRL to a certain extent, and is gaining wider and wider application in a variety of CNRL products. In this study, four CNRL preservatives, BCT-2, HY, HM and LS, were used to prepare low ammonia CNRL, and the differences between the performances of low ammonia CNRL in different preserved systems were investigated by comparison with high ammonia CNRL. The results showed that the four preservation systems had good effect on the preservation of low ammonia CNRL, and all of them could meet the requirements of GB/T 8289—2016 national standard. Among them, the low ammonia CNRL preserved by BCT-2 had the lowest volatile fatty acid value (VFA No.), but the viscosity value was the highest, the lowest mechanical stability (MST); in addition, the average particle size of rubber particles was higher; the thermal stability and zinc oxide mechanical stability (ZST) were lower; the dry rubber film strength was higher. The low ammonia CNRL preserved by HY had the lowest VFA No., the lowest viscosity, highest MST and thermal stability; the fastest pre-cure speed; pre-cure latex with the lowest viscosity, highest MST and thermal stability; higher strength of vulcanized rubber film. HM preserved low ammonia CNRL with lower viscosity; higher MST and good stability; the lowest dry rubber film strength; the slowest pre-cure speed. LS preserved low ammonia CNRL with higher VFA No. and higher viscosity value; lower MST and poor stability; the smallest rubber particle size; the highest concentrated latex dry rubber film and vulcanized rubber film strength; the best dry rubber film thermal stability. Contrast analysis showed that HY and LS saved better overall performance of low ammonia CNRL, where HY low ammonia CNRL was suitable for the production of foam products, adhesives, etc., while LS low ammonia CNRL was suitable for the production of gloves, balloons and other pure rubber impregnated products.

The trunks of ten-year-old Aquilaria sinensis trees were filled with high-pressure nitrogen gas and treated every 7 and 15 days for 3 consecutive months. The wood discoloration area was observed and measured, the content of alcohol-soluble substances was detected, and the chemical composition and relative content of the agarwood were analyzed by GC-MS at 7 and 10 months after treatment. The effect of nitrogen gas filled on the agarwood formation was discussed, which would provide a feasible induction method for artificial agarwood formation. The results showed that nitrogen treatment significantly increased the longitudinal discoloration length and transverse discoloration width of wood trunks, and the results of the treatment filled with nitrogen gas every 7 days (N₇) were better than that of the treatment filled with nitrogen every 15 days (N₁₅). Ten months after N₇ treatment, the discoloration area was the largest, and the length of agarwood zone and total discoloration zone in both longitudinal and transverse direction were significantly longer than those of N₁₅ and CK₁. Inflating nitrogen treatment could significantly increase the content of alcohol-soluble substances and agarotetrol, and the content of agarwood zone was higher than that of transition zone. The content of alcohol-soluble substances and agarotetrol in agarwood area increased by 14.04% and 28.47% compared with that of N₁₅ and CK₁, respectively, and the content of agarotetrol was 0.12%, which significantly higher than that of N₁5 and CK₁, seven months after N₇ treatment. The content of alcohol-soluble substances and agarotetrol in each treatment increased with the increase of treatment time. Ten months after N₇ treatment, the content of alcohol-soluble substances and agarotetrol in agarwood zone was 19.37% and 0.30% respectively, which was noticeably higher than that of N₁₅ and CK₁. The content of alcohol-soluble substances and agarotetrol in N₁₅ treatment increased by 9.42% and 51.50% respectively, compared with CK₁. The volatile component of agarwood in N₇ treatment was the highest, which was rich in 25 terpenes, 5 chromones and 8 other compounds, and the total relative content of terpenes and chromones reached 66.09%, significantly higher than that of N₁₅ and CK₁.

In order to objectively select new rubber tree clones suitable for China's rubber planting environment, the yield and secondary characters of four introduced clones 'Reshi 09-5' 'Reshi 09-6' 'Reshi 09-7' and 'Reshi 09-10' were systematically identified and evaluated. The results showed that among the four clones, just 'Reshi 09-7' showed fast-growing, not yet in yield. Only 'Reshi 09-5' was close to the control in the first taping year and was lower in other years. The results of latex physiological characteristics showed that, according to good latex stability, fast latex discharge and high sugar utilization rate, 'Reshi 09-5' showed good rubber production potential, had higher thiol content and lower sucrose content than that of 'RRIM600', and there was no significant difference in dry rubber yield and initial speed of latex discharge between them. 'Reshi 09-6' had higher dry rubber content and plugging index, thicker original bark and more latex tubes number than 'RRIM600', and there was no significantly differences in initial flow rate and sucrose content between them. It was considered that the variety had good rubber production potential, but the metabolic intensity of latex was low. It had better potential in latex production, but a low metabolic intensity, so the production could be increased by stimulated tapping. The results of raw rubber properties, physical and mechanical properties, molecular weight and molecular weight distribution of vulcanizates of different varieties showed that there were some differences among the four clones. 'Reshi 09-5' showed the lowest in plastic initial value and Mooney viscosity, but the highest plastic retention rate. 'Reshi 09-6' showed the highest Mooney viscosity. According to larger weight-average molecular weight, 'Reshi 09-7' showed good physical and mechanical properties. In terms of stress resistance performance, 'Reshi 09-5' had the lowest wind damage collapse rate and 'Reshi 09-10' had the highest. The results of cold-resistant outpost data showed that under the condition of no cold injury in the control clone '93-114', the cold injury grade of 'Reshi 09-5' was 1.00, and that of 'Reshi 09-7' was 0.17. The comprehensive analysis results showed that the fast-growing traits of the four introduced clones were obvious. 'Reshi 09-6' had good rubber production potential. 'Reshi 09-5' had better wind resistance than 'RRIM600', 'Reshi 09-7' had good adaptability in cold damage. Among the four clones, 'Reshi 09-6' showed better performance in yield, girth growth, latex physiological characteristics and latex quality, and suitable to popularize and cultivate in same condition.

In this study, the soluble dietary fiber of coffee peel and other five commercially available soluble dietary fibers obtained from soybean, inulin, jujube, oat, and celery were used as experimental materials. The particle size distribution, monosaccharide composition, microstructure, physico-chemical properties, and functional characteristics were compared analyzed. Results indicated that the particle size distribution of soluble dietary fiber in coffee peel was wider, and the homogeneity was relatively poorer than that of the other five soluble dietary fibers, but its monosaccharide composition was relatively rich, and a total of 10 kinds of monosaccharides were detected. Fourier transform infrared spectroscopy showed different samples had similar spectral characteristics, but a slightly different intensity response of characteristic bands. X-ray diffraction and differential scanning calorimetry results demonstrated that the crystalline of soluble dietary fiber from coffee peel was lower (38.84%) than that of other samples, but exhibited excellent thermal stability. The solubility and oil holding capacity of soluble dietary fiber in coffee peel was 90.9% and (2.18±0.03)mg/g, respectively. The nitrite absorption capacity of soluble dietary fiber in coffee peel was 7.93 mg/g, which was significant higher that of the other samples. This study could provide theoretical basis for high value utilization and product development of coffee peel resource.

Tribe Vandeae belongs to Orchidaceae and is distributed at low altitudes in southern and southeastern Tibet. Due to the limited transportation conditions in the past, understanding of tribe Vandeae species in Tibet was poor. We reporte a less known species of orchids from China: Papilionanthe uniflora (Lindl.) Garay. It was originally only recorded in the Flora of Tibet, but was not included in the Flora of China due to the lack of important features such as flowers. This article provides detailed information about the anatomy of this species for future supplement and revision. The following 12 new recorded species are reported in Tibet: Aerides rosea Lodd. ex Lindl. & Paxton, Cleisostoma aspersum (Rchb. f.) Garay, Cleisostoma linearilobatum (Seidenf. & Smitin.) Garay, Cleisostoma racemiferum (Lindl.) Garay, Cleisostoma simondii (Gagnep.) Seidenf., Gastrochilus affinis (King & Pantl.) Schltr., Gastrochilus prionophyllus H. Jiang, D. P. Ye & Q. Liu, Gastrochilus pseudodistichus (King et Pantl.) Schltr., Phalaenopsis lobbii (Rchb. f.) H. R. Sweet, Taeniophyllum glandulosum Blume, Uncifera obtusifolia Lindl. and Vanda concolor Blume, Uncifera Lindl. is a new recorded genus in Tibet. We providedetailed descriptions of morphological identification and pictures. Mos Vandeae species have important ornamental value, such as Phalaenopsis and Vanda. The findings not only expand orchid resources in Tibet, but also provide basic information for the utilization of ornamental orchids in Tibet.