Litchi (Litchi chinensis Sonn.) is one of the most distinctive fruits in South China and is one of the pillar industries of rural economy in South China. At present, the cultivated area of litchi in China is more than 533 000 hm² and the output is more than 2.3 million tons, accounting for more than 80% of the total cultivated area and more than 65% of the total output in the world. The panicle of litchi is paniculate, terminal, generally composed of cymes, with a length of 10-40 cm and 200-1500 florets. Excessive number of florets will consume tree nutrition and affect litchi fruit setting. Therefore, reducing the number of florets by regulating branches is an effective measure to improve fruit setting. SUPPRESSOR OF MAX2 1-LIKE 7 (SMXL7) is an important component of strigolactone signaling pathway and a new inhibitor with dual functions. SMXL7 is involved in leaf morphology regulating and branch development in Arabidopsis and rice. In order to identify the regulatory factors involved in the panicle branch development in litchi, LcSMXL7 the homologous of arabidopsis SMXL7 was cloned, the sequence of LcSMXL7 was obtained from RNA-seq data and the gene sequence, physicochemical properties, evolutionary relationships, conserved domain, tissue expression pattern, subcellular localization and gene function were analyzed. The open reading frame of LcSMXL7 was 3408 bp length, encoding 1135 amino acids. LcSMXL7 protein contained two CLP domains and one AAA_2 domain. The molecular formula, molecular weight and theoretical isoelectric point of LcSMXL7 was C₅₄₂₉H₈₆₃₂N₁₅₃₀O₁₇₁₅S₃₈, 123.99 kDa and 5.96. The Instability index, aliphatic index and grand average of hydropathicity of LcSMXL7 was 46.38, 83.74 and -0.305, respectively. LcSMXL7 was highly expressed in stems, seeds and leaves, followed by panicle, male flowers and pericarps, while the expression was low in female flowers, pulp and roots. Phylogenetic tree analysis showed that LcSMXL7 was closely related to SMXL7 protein from woody fruit trees sweet orange and mango. Subcellular localization analysis showed that LcSMXL7 was located in the nucleus, suggesting that it may participate in the regulation of gene expression as a transcription factor. Transgenic results showed that overexpression of LcSMXL7 in Arabidopsis could significantly increase the number of branches, indicating that LcSMXL7 could positively regulate the development of branches in Arabidopsis. We clarified the LcSMXL7 protein characteristics, tissue expression pattern, evolutionary relationships, conserved domain, subcellular localization and gene function, which would build a foundation for elucidating the molecular mechanism of LcSMXL7 in branch development.

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.

C2H2 zinc finger protein is one of the most common zinc finger proteins and widely found in eukaryotes. It plays an important role in plant growth and development, abiotic stress response to salt, low temperature and drought stress. In this study, the C2H2 amino acid sequence of Arabidopsis thaliana were used to blast with local BLASTP in the oil palm genome database and to predict the conservative domains, and to screen the C2H2 zinc finger protein family of oil palm. The physical and chemical properties, evolutionary relationships, chromosomal location, gene structure, conservative motif and promoter cis-elements were analyzed through bioinformatics softwares, the expression of EgC2H2 gene was analyzed by the transcriptome data and real-time fluorescence quantitative PCR under low temperature stress. A total of 73 C2H2 type zinc finger protein family members were identified from the genome of oil palm. The number of amino acids in EgC2H2 family was between 128 and 556, The molecular weight was between 14 176.73 and 58 983.30 Da, the isoelectric point was between 4.99 and 9.62, the instability index was between 38.84 and 86.01, and the gravy was between -1.154 and -0.226. Subcellular localization showed that the C2H2 gene family were localized in the nucleus. Phylogenetic tree analysis showed that EgC2H2 family members were divided into four subfamilies, most members of EgC2H2 family were classified into subfamily Ⅰ and subfamily Ⅱ, and the domains of the same subfamily members were highly consistent. Chromosome location results showed that EgC2H2 family members were unevenly distributed on the 16 chromosomes of oil palm. Analysis of promoter cis-elements showed that the EgC2H2 family contained many promoter cis-elements related to light response elements, plant hormones response elements and stress response elements. Transcriptome analysis showed that most EgC2H2 genes responded to low temperature stress, and most EgC2H2 genes were highly expressed in cold-tolerant materials and low expressed in cold-sensitive materials. qRT-PCR analysis showed that the expression level of EgC2H2-23, EgC2H2-11, EgC2H2-19, EgC2H2-17 and EgC2H2-21 was significantly up-regulated, and the expression level of cold-tolerant materials was significantly higher than that of cold-sensitive materials. It was speculated that the genes would play a key role in oil palm response to low temperature stress, and can be used as candidate genes for further study. This study would provide theoretical reference for further study on the functional analysis of C2H2 gene family in oil palm.

In this study, 27 phenotypic traits of the floral organs of 135 Phalaenopsis varieties were observed and analyzed to provide a theoretical basis for the utilization of Phalaenopsis germplasm resources and the directional breeding of new varieties. 135 Phalaenopsis germplasm resources collected and preserved in the Fuzhou Branch of the New Plant Variety Testing Center of the Ministry of Agriculture and Rural Affairs were used as the test materials to collect data on 27 phenotypic traits of Phalaenopsis orchid organs and analyze the flower phenotypic traits. The distribution frequency, coefficient of variation, Simpson index and Shannon-Wiener index, and correlation, principal component and cluster analysis of quantitative traits were studied. The majority of butterfly orchid organs were violet petals, racemes, separated petals and no fragrance, which accounted for 31.85%, 60.74%, 79.26% and 84.44% of the corresponding description distribution frequencies respectively. The Simpson index and Shannon-Wiener index of the lobes in the lip were the highest, 0.992 and 7.047, respectively, and the diversity was the most abundant. The variation coefficient of quantitative traits ranged from 19.79% to 52.72%, of which the coefficient of variation of the number of inflorescences was the largest, which was 52.72%. Most of the main quantitative traits had extremely significant positive correlations. Principal component analysis extracted 3 quantitative traits as the representative traits for evaluating Phalaenopsis phenotypic traits, and calculated comprehensive scores. The top 3 were 'JB2312', 'Wanhuayanhuo' and 'Dongfanghong' respectively. The R-type cluster analysis showed that the 16 quantitative traits of Phalaenopsis could be divided into 4 categories, and the Q-type cluster analysis showed that the 135 Phalaenopsis varieties were divided into 5 major species groups. Our research indicates that the flower phenotypes of 135 Phalaenopsis varieties have rich genetic diversity.

In order to promote the application of digital image processing technology in forest nutrition diagnosis and realize real-time monitoring of forest growth status and nutrient content, three prediction models of the total nitrogen content of young Aquilaria sinensis Lignum Resinatum based on image color and shape characteristics were constructed in this study, which provided a theoretical basis for nutrition diagnosis of young forest tree. Firstly, the optimal K value is determined according to the boundary distance and the size of the setting error, and the improved K-Means algorithm is used to extract the foreground image. Then, separate the three channels of R, G, and B of the foreground image and calculate the average value respectively. Then, the R, G, and B three channels of the foreground image are separated and the mean values are calculated respectively. According to the image color space conversion formula, the image is converted to HIS and Lab color space respectively, and the hue (H), saturation (S), brightness (I), brightness (L), red to green channel (a), yellow to blue channel (b), and a total of 9 color features are obtained. Find the minimum circumscribed rectangle of the foreground image, calculate the area (CA) of the foreground image, the area (RA), perimeter (RC), and rectangularity (RD) of the minimum circumscribed rectangle of the foreground image, and obtain four shape features in total. Finally, principal component analysis was performed on the color features, shape features, and color features + shape features, and the obtained three types of principal components were used as independent variables to construct a prediction model for the total nitrogen content of young A. sinensis, and the accuracy of the three models constructed was tested. Finally, the principal component analysis of color feature, shape feature, and color feature +shape feature was carried out respectively, and the three principal components obtained were used as independent variables to construct the prediction model of the total nitrogen content of young A. sinensis, and the accuracy of the three models was teste. The results show that improving the K value selection method can reduce the uncertainty of the K-Means clustering segmentation algorithm, enhance the segmentation efficiency of the algorithm, and achieve accurate segmentation of A. sinensis visible light images. The three models of the total nitrogen content of young agarwood constructed in this study had good prediction ability. The model accuracy based on single image parameters was basically the same, but the model based on shape features used fewer parameters and had higher relative modeling efficiency. The two-image parameter model uses more parameters than the single-image parameter model, but the fitting degree is better and the accuracy is higher. In practical applications, it can be selected according to different needs. In this study, different image features were used to build a total nitrogen model, which better realized the non-destructive estimation of the total nitrogen content of young trees, and provided a certain reference for precision forestry.

To select suitable slow-release fertilizers for sugarcane productions the endophytic bacterial community structure in the stems of sugarcane under different slow-release fertilizer applications were analyzed. Based on high-throughput sequencing techniques, the endophytic bacterial community structure in the stems of sugarcanes among conventional fertilization (CK) and different slow-release fertilizers (A-F treatments) were analyzed. In comparison with CK, the diversity of the endophytic bacteria in the stems of sugarcanes was significantly increased by adding long- acting agent (235 g/t) and synergist (3 g/t and 18 g/t), but the richness of the endophytic bacteria in the stems of sugarcanes was not significantly improved by slow-release fertilizer applications except adding long-acting agent (235 g/t) treatment C. Meanwhile, Herbaspirillum was the specific endophytic dominant bacterial genus in CK. Sporocytophaga and Cellvibrio were the unique endophytic dominant bacterial genera in the slow-release fertilizer adding long-acting agent (125 g/t) treatment A. However, no specific endophytic dominant bacterial genera could be found in the slow-release fertilizer adding long-acting agent (150 g/t) treatment B. Norank_f__SC-I-84, norank_f__Neisseriaceae, norank_f__JG30-KF-AS9 and Massilia were the specific endophytic dominant bacterial genera in the slow-release fertilizer adding long-acting agent (235 g/t) treatment C. Brevundimonas, Enterobacter, Staphylococcus were the unique endophytic dominant bacterial genera in the slow-release fertilizer adding synergist (3 g/t) treatment D. Cloacibacterium was the specific endophytic dominant bacterial genus in the slow-release fertilizer adding synergist (8 g/t) treatment E. And unclassified_f__Burkholderiaceae, Paenibacillus, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Corynebacterium_1, Chryseobacterium were the specific endophytic dominant bacterial genera in the slow-release fertilizer of adding synergist (18 g/t) treatment F. Furthermore, the functions of the endophytic bacteria in the stems of sugarcanes did not show significantly different between CK and applications of slow-release fertilizer treatments. In comparison with CK, the diversity of the endophytic bacteria in the stems of sugarcanes was significantly increased by adding longacting agent (235 g/t) and synergist (3 g/t and 18 g/t), but the richness only could be significantly improved by application with slow-release fertilizer adding with long-acting agent (235 g/t) treatment C. Except of slow-release fertilizers +long-term agent (150 g/t) treatment B, specific endophytic bacterial genera in the stems of sugarcanes all could be detected under slow-release fertilizer applications. Although the whole functions of the endophytic bacteria in the stems of sugarcanes were not significantly altered by slow-release fertilizer applications, higher stress resistant abilities could be concluded in sugarcanes under most of slow-release fertilizer applications (B-F treatments). Among them, the highest promotion and stress resistant effect on sugarcanes growth was the slow-release fertilizer + 235 g/t long-acting agent treatment (C) according to the composition and function of endophytic bacteria in stems of sugarcanes.

Eucalyptus urophylla × E. grandis is a hybrid of Eucalyptus grandis (♂) and Eucalyptus urophylla (♀). It has the advantages of rapid growth, straight trunk, high yield, short rotation period, easy to germinate, strong adaptability and so on. So it has become the main cultivated tree species in the key forest areas, important commercial timber forest bases and forest products industrial bases of Yunnan Province. Due to its endogenous plant growth inhibitors, the disposal of wood processing residues has not yet been effectively solved. In this study, urea, manure from chicken and sheep, EM bacteria and enzyme bacteria were added to Eucalyptus bark for decomposing fermentation to promote the degradation of its endogenous inhibitors, making it an organic substrate with similar physical and chemical properties to peat. In order to reveal the effects of three levels of decomposed Eucalyptus bark (raw/40-day/60-day) compounding with three volume ratios (10%, 20% and 30%) of perlite on the enzymatic activity at plant seedling stage, four crops (Lycopersicon esculentum, Brassica oleracea, Lactuca sativa and Moringa oleifera) were cultivated in a greenhouse using the two-factor and three-level experimental design. After 6-8 weeks of growth, the activity of six enzymes associated with carbon and nitrogen metabolism (SS, SPS, Rubisco, GS, GOGAT, NR) in the leaves was determined. The results showed that the decomposition level and the proportion of perlite had the extremely significant interaction on the SPS activities of L. esculentum, B. oleracea and L. sativa (P<0.01). On the whole, the activity of enzymes related to nitrogen metabolism was more affected by the decomposition level than those related to carbon metabolism. The enzymatic activity of the three vegetables in 60-day-decomposed Eucalyptus bark were significantly higher than those in the control peat, raw Eucalyptus bark and 40-day-decomposed Eucalyptus bark (P<0.05). Among them, the enzyme activity of L. sativa in compound 30% perlite was significantly higher (P<0.05). In addition, the enzymatic activity of the three vegetables in 40-day-decomposed Eucalyptus bark compounding with 20% perlite were significantly higher than those in peat (P<0.05). The enzymatic activity of M. oleifera in peat was significantly higher than that in Eucalyptus bark substrate (P<0.05), and that in raw Eucalyptus bark was significantly higher than that in decomposed Eucalyptus bark. Besides, the mechanism of endogenous compounds in Eucalyptus bark influence on the activity of enzymes related to carbon and nitrogen metabolism during plant growth needs to be further studied.

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 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.

Agave spp. is main resource of hard fiber. Zebra disease, caused by the pathogen Phytophthora nicotianae, is one of the most devastating sisal oomycete diseases. RXLR effector proteins are important cytoplasmic effectors of oomycete and more than 300 RXLR effector genes were identified in the genomes of P. nicotianae. RXLR effectors have the ability to manipulate or suppress host immunity by directly binding host proteins. A typical RXLR effector (named PnRXLR5863) that induced programmed cell death (PCD) was identified from P. nicotianae, but the targets in Agave were still unknown. This study aims to obtain the host plant proteins that are interacting with PnRXLR5863 in A. hybrid No.11648. A normalized cDNA library was constructed by combining Switching Mechanism at 5′ end of RNA Transcript (SMART) and Duplex-Specific Nuclease (DSN) technology. The capacity of cDNA library was 5.32×10⁷ CFU/ml, the independent clones was 1.064×10⁸ CFU, and the lengths of inserts ranged from 0.5 kb to 3.0 kb, with the recombination rate of 100%. A total of 23 proteins interacting with PnRXLR5863 were obtained by sequencing and homology analysis. Some of target proteins involve several physiological events, such as ubiquitination, protein synthesis, protein translation and protein translation, suggesting that PnRXLR5863 effector may act on protein metabolism of Agave spp. This research would lay a foundation for further study of the pathogenic mechanism of PnRXLR5863.