Aquaporins (AQPs), assembled in tetramers at the biological membrane, constitute a class of integral membrane proteins facilitating the passive transport of water. Natural rubber, which is specifically synthesized in the laticifer located in the secondary phloem of the rubber tree (Hevea brasiliensis) trunk, is expelled out in the form of latex that represents the cytoplasmic content of laticiferous cells upon tapping. Water, accounting for approximately 70% of the latex upon each tapping, plays a crucial role in the latex production by regulating the latex viscosity and laticifer turgor. Previous studies suggested that the water balance of laticifers is governed by plasma membrane intrinsic proteins (PIPs) especially HbPIP2;3, an efficient and abundant water transporter. To uncover the regulation mechanism of HbPIP2;3 in the laticifer water balance, its 861 bp full-length coding sequence (CDS) was isolated using RT-PCR. Sequence analysis revealed that HbPIP2;3 putatively encoded 286 amino acids with the theoretical molecular weight (MW) of 30.58 kDa, the isoelectric point (pI) of 8.50, the instability index (II) of 31.68, and the grand average of hydropathicity (GRAVY) of 0.449, implying its basic, hydrophobic, and stable features. The protein was shown to contain one conserved MIP (major intrinsic protein) domain, which including six typical transmembrane helices (i.e. TM1-6) as well as two half helices (i.e. HB and HE). 3D prediction via homology modeling suggested that HbPIP2;3 could assemble in homotetramer. In accordance with the bioinformatics prediction, transient over-expression of HbPIP2;3 in Nicotiana benthamiana leaves supported the cell membrane localization, which was also confirmed by bimolecular fluorescence complementation (BiFC). Moreover, BiFC revealed that HbPIP2;3 could interact itself, which was further confirmed by yeast two-hybrid. The results showed that HbPIP2;3 may be involved in the laticifer water balance in the form of homotetramer at the plasma membrane, however, whether it could also function in hereotetramer still needs to be addressed.

The heat shock transcription factor MeHsfB3b is important in regulating the resistance to cassava bacterial blight. In the previous study, the candidate interaction protein MeFKBP20 of MeHsfB3b was obtained by the yeast two-hybrid technology, which belongs to the FKBP-type peptide prolyl cis-trans isomerase gene family. In this study, the full-length MeFKBP20 gene was cloned to be 561 bp, encoding 186 amino acids, with a molecular weight of 19.99 kDa and a FKPB_C domain. The expression pattern analysis showed that MeFKBP20 was highly expressed in mature leaves and roots of cassava, and the expression level of young leaves and petioles was low. It could quickly respond to the in-duction of pathogen XpmCHN11 and maintain a high expression abundance, suggesting that it is involved in response to pathogen infection. The interaction between MeHsfB3b protein and MeFKBP20 protein through 201-241 aa region was proved by the yeast two-hybrid point-to-point and bimolecular fluorescence complementation experiments. The results of this study are helpful to further analyze the mechanism of MeHsfB3b gene regulating cassava resistance to cassava bacterial blight.

Phosphatidyl ethanolamine-binding protein (PEBP) widely exist in plants and play important roles in regulating flowering, seed dormancy and the formation of underground storage organs (e.g. potato tubers and onion bulbs). However, up to now, there is few studies conducted on PEBP genes in sweet potato (Ipomoea batatas), and there is also no research published to reveal the key members of PEBP gene family that regulate the development of storage root of sweet potato. Our study first identified the number and types of the PEBP gene family in sweet potato through bioinformatics analysis. Then, to screen the candidate members of the PEBP gene family that regulate the development of storage root of sweet potato, the tissue specificity of PEBP gene expression and the dynamic changes of PEBP gene expression level in storage roots at different development stages were analyzed. To explore possible regulatory mechanism, the correlation between PEBP gene expression level and SWEET gene expression level in storage roots were also examined. The results are as follows: (1) A total of 15 putative PEBP genes were identified from the sweet potato genome, which were classified into 4 subfamilies: 5 of FT-like genes (IbFT1-5), 6 of TFL1-like genes (IbTFL1-6), 2 of MFT-like genes (IbMFT1-2), and 2 of PEBP-like genes (IbPEBP1-2). (2) Clustering analysis revealed that IbFT5 may promote the development of storage root of sweet potato, while IbTFL3 may inhibit the development. (3) The tissue specificity analysis of sweet potato PEBP gene expression showed that IbFT5, IbTFL4 and IbTFL6 not only showed higher expression levels in the diverse root tissues than in other tissues, but also had higher expression levels in roots than other PEBP genes. Therefore, it is speculated that the three PEBP genes may promote root enlargement. (4) The expression levels of the four candidate PEBP genes (IbFT5, IbTFL3, IbTFL4 and IbTFL6) obtained from the above two methods were determined in storage roots at different developmental stages (30, 60, 90 and 120 days after planting). It was found that the expression levels of IbFT5, IbTFL4 and IbTFL6 significantly increased with the development of root tubers, especially during the rapid expansion period (60-90 days), while the expression level of IbTFL3 rapidly de-creased during the rapid expansion period (60-90 days). Therefore, all the above measurement results indicate that IbFT5, IbTFL4 and IbTFL6 may promote root development, while IbTFL3 may inhibit root development. (5) With the increase of expression levels of IbFT5, IbTFL4 and IbTFL6, the expression levels of four out of the five highly ex-pressed SWEET genes (IbSWEET4, IbSWEET11, IbSWEET16 and IbSWEET19) in storage roots showed a continuous decreasing trend. This result is similar to the findings in potatoes, indicating that the PEBP gene of sweet potato may also inhibit SWEET activity and thus promotes the transportation of sugar to the storage roots through more efficient symplasmic pathway, which ultimately promotes the development of storage roots. In conclusion, this study not only determined the number and types of members of the PEBP gene family in the sweet potato genome, but also systematically identified four candidate PEBP genes affecting the development of sweet potato storage roots, which can provide a theoretical basis for further improvement of sweet potato yield in China.

Anacardium occidentalie Linn is a typical tropical fruit tree, which is mainly planted in Yunnan and Hainan provinces of China. Cashew cultivation has important economic, social and ecological values. It is of great value to realize realize the strategy of rural revitalization in China, increase farmers' production and income, and achieve common prosperity. Cashews are very sensitive to low temperatures, and they will be severely damaged at 8 ℃and the growth will stop. Therefore, lowtemperature stress is an important abiotic stress that restricts cashew growth. CBF transcription factors play important roles in plant response to abiotic stresses such as low temperature, drought and salt. However, the role of CBF gene family in cashews has not been elucidated, and the expression pattern of this family in response to low temperature stress is unknown. In this study, in order to explore the basic characteristics of the CBF gene family in cashew nuts, six AoCBF gene family transcription factors were identified and obtained from the cashew transcriptome by bioinformatics methods, and the physical and chemical properties, protein structure, phylogeny, promoter action elements and expression patterns under low temperature induction were analyzed. The length of the six AoCBF proteins ranged from 189 to 334 aa, and the molecular weight of the proteins ranged from 21.31 to 37.89 kDa. The isoelectric points of the six AoCBF proteins were less than 7, indicating that the proteins were acidic. The proteins all contained an AP2/ERF domain. Motif analysis showed that there were five motifs in AoCBF genes, and the absence of different AoCBF gene motifs implied the absence of related functions. Phylogenetic tree analysis showed that the six AoCBF genes could be divided into two subgroups, A and B, in which group A contained one gene and group B only contained five genes. The analysis of homeotropic elements of promoter showed that AoCBF gene might be involved in the response to hormone and abiotic stress. Fluorescence quantitative expression analysis showed that all the six AoCBF genes responded to low temperature and cold stress to different degrees, indicating that AoCBF played a role in the biological process of cashew nut in response to low temperature stress. The results summarized the basic characteristics of the AoCBF gene family and accumulated basic data for further molecular resistance research and application of cashews AoCBF genes.

Bulbophyllum is the largest genus and the most rapidly differentiated group in the family of Orchidaceae. This paper reports 5 new recorded species of Bulbophyllum from Tibet, China. Bulbophyllum depressum King & Pantling, B. drymoglossum Maxim., B. lingii M. Z. Hang, G. S. Yang & J. M. Yin, B. menglunense Z. H. Tsi & Y. Z. Ma, B. secundum Hook. f. B. depressum is similar to B. menglunense, but the difference is that the former has very short scape and halberd-shaped lip; B. drymoglossum is a peculiar species of the genus, with small plants and no pseudobulb; B. lingii is similar to B. pentaneurum, but the difference is that the former pseudobulb is spherical and the lip is cylindrical; B. menglunense is similar to Bulbophyllum depressum, but the former has longer scape and its lip are narrowly lanceolate; the plant of B. secundum is similar to B. parviflorum, but the difference is that the middle sepal margin of the former has eyelashes, the lateral sepal margins are entire, and the lip is lanceolate. This discovery greatly enriched the background data of Orchids in Tibet, and also indicated that the investigation of orchids resources in this area was lagging behind.

To study the characteristics of free amino acids in wampee, the scientific evaluation of the effects of free amino acids in different wampee germplasm on fruit flavor and medicinal value, the contents of 20 common free amino acids were determined using HPLC with the pulp of 20 wampee germplasms. By using taste activity values, principal component analysis and cluster analysis were used to comprehensively evaluate each wampee germplasm. The results showed that the pulp contained 18 kinds of free amino acids except Cys and Arg. The content was significantly different among major wampee germplasm. The mass concentration of total free amino acids of the 20 wampee germplasms ranged from 1309.7 to 9832.0 mg/kg, among which the content of non-essential amino acids was the highest, the content of essential amino acids was the second, and the content of essential amino acid for children was the lowest. And the content of medicinal amino acids ranged from 6.3% to 18.6% of the total free amino acids, of which Asp and Glu were the major components. According to the different flavor characteristics of amino acids, 18 amino acids were divided into three categories of flavor amino acids, and found that M1 had the highest content of sweet amino acids, and G2 had the highest content of delicious and bitter amino acids. And the TAV of Ala in 16 wampee germplasm resources and Asp and Asn in a few wampee germplasm resources was greater than 1, which contributed to the flavor of wampee. Most free amino acid showed significant or highly significant positive relationships. Meanwhile, four principal components were extracted by principal component analysis, and the cumulative contribution reached 89.766%, which could better reflect the comprehensive characteristics of free amino acids of pulp. In general, the overall scores of each wampee germplasm ranged from –3.18 to 3.51, with M1 having the highest overall score. The 20 wampee germplasms were then clustered into three major groups by clustering analysis, among which X2, Y-1, G2 and M1 of group Ⅲ had high contents of total free amino acids, medicinal amino acids and flavor amino acids, with good amino acid nutritional quality and flavor quality. The results could provide some reference for superior seed breeding and quality evaluation.

Screening new sugarcane varieties with high light efficiency could guarantee the high-quality development and sugar safety. Chlorophyll fluorescence parameters were measured and calculated from Lake-model for 3 commercial varieties and 10 new varieties to investigate the sugarcane photosynthetic potential under cloudy and sunny day through the mechanism model of photosynthetic electron flux (J) response to light. The results showed that light energy balanced between photosynthetic election transport and regulated energy dissipation (Φ_NPQ) under low and high light, the appearance of increased non-regulated energy dissipation (Φ_NO) under middle light resulted from the different transition mode among each sugarcane varieties according to increasing photo active radiation (PAR) other than photo-damage. Compared with in sunny day, the initial light utilization rate (α_e) of all sugarcane varieties was significantly higher in cloudy day, but J showed sharp decrease at the same PAR level. RG16117 and RG 1997 exhibited the highest photo-quantum efficiency (Φ_II) in cloudy and sunny day respectively, which showed no significantly difference between RG16239 and RG1997 under high light. Φ_II of RG16239 was lower than ROC22 and RG1997 under low and middle light with the lowest Φ_NO, but the saturate PAR and maximum J were relatively high under high light. The photosynthetic electron transport capacity index (J_PT) based on the weight ratio of cloudy and sunny days in recent 5 years exposed as RG1997 (21.93)>ROC22 (21.43)>ROC16 (20.62)>RG16239 (20.27)>GL05136 (19.43)>RG11713 (19.30)>RG1462 (19.29)>RG14291 (19.03)>RG16117 (18.94)>RG1339 (18.93)>RG1876 (18.08)>RG1 (17.41)>RG11559 (16.84), which made RG1997 and RG16239 high light efficiency varieties.

In order to explore the formation mechanism of fruit color difference between Dahong and Wucihuanglong pitaya, the fruits at different development stages of 13 d, 16 d, 19 d, 22 d, 25 d and 28 d after fruit setting were sampled. The color parameters, total content, components and relative content change of Betalains in different parts (flesh, peel and sepal) were determined, and the results were analyzed by correlation and principal component analysis. Results showed that a^* value of Dahong flesh gradually increased and the flesh showed red color 16 days after fruit setting. The a^* value of the peel and sepal was negative before 19 d after fruit setting, positive during 19 d to 28 d and showed an upward trend; the b^* value significantly increased and then decreased after 22 d after fruit setting, showing that green first turned to red and yellow, then turned to red. The a^* value of the peel and sepal of Wucihuanglong was negative before 25 d, and the absolute value of 28 d was close to 0; the b^* value showed a stable trend during 13 d to 19 d after fruit setting, and then increased significantly, showing that green turned to yellow. A total of 11 kinds of betalains were detected in Dahong, and the content of betanin was the highest. The total content increased gradually, and the increase was significant at 28 d. A total of 6 kinds of betalain components were detected in the Wucihuanglong, and leucine betaxanthin content was the highest, while the flesh only contained betanidin and tyrosine. There was no significant difference in the total content of betalains in flesh, but it increased gradually in peel and sepal. There was only one common component of betanidin between the two varieties. According to the correlation analysis, the a^* value of the three parts of Dahong was significantly positively correlated with the total content of betalains and extremely significantly positively correlated with the content of betanin. The b^* values in the peel and sepal of Wucihuanglong were significantly positively correlated with the total content of betalain and the content of leucine betaxanthin, while the correlation between the total content of betalain in the flesh and the a^*, b^* and L^* values was not significant. The principal component analysis of the betalains of the two varieties showed that Dahong extracted four principal components, and the cumulative variance contribution rate was 79.23%. The contribution rate of the first principal component was 34.30%, which mainly integrated the components of betanin and phyllocactin. The comprehensive contribution rate of the second principal component betaine and metabolites was 21.35%, mainly synthesizing 2,17-Decarboxyphyllocactin and betalamic acid. Two principal components were extracted from Wucihuanglong, and the accumulative rate reached 84.21%. The contribution rate of the first principal component betaxanthin was 61.71%, which mainly integrated leucine-betaxanthin, tyrosine-betaxanthin and other components, which provided a new idea for color evaluation and breeding of pitaya. In conclusion, the peel and sepal of Dahong and Wucihuanglong gradually changed color with the increase of betalains. The flesh of Wucihuanglong contained only metabolites of betalains, and did not change color. Combined with correlation and principal component analysis, it was further speculated that the red color of Dahong was mainly contributed by betanin, phyllocactin and 2,17-Decarboxyphyllocactin, and the yellow color of Wucihuanglong peel and sepal was mainly contributed by leucine-betaxanthin. This would provide a new idea for the evaluation of pitaya color. This study described the formation mechanism of color difference of pitaya, and would lay a theoretical foundation for exploring the color mechanism, color evaluation, as well as the development and utilization of betalains.

The quality analysis of Chinese cherry fruit is beneficial to the selection and breeding of cherry varieties suitable for regional development. At the same time, it also lays a theoretical foundation for the protection of Chinese cherry germplasm resources. In this experiment, combining principal component analysis, correlation analysis and cluster analysis methods, 30 Chinese cherry fruits of different varieties (excellent lines) under the same cultivation conditions were selected for external and internal quality analysis. The results showed that there were significant differences in fruit quality among different varieties of Chinese cherry under the same cultivation conditions. The scores of comprehensive character evaluation ranked as C78, C6, C14, C34 and C32. Variety C20 (Manaohong) has excellent cultivation performance in some provinces in China, ranked 11th in this comprehensive evaluation. The 9 fruits intrinsic quality indexes had varying degrees of variation, with variation coefficients ranged from 11.27% to 36.32%. There was a correlation coefficient between the quality indicators, among which 12 were significantly correlated at 0.01 level and 17 were significantly correlated at 0.05 level. Principal component analysis of 13 quality traits showed that the cumulative contribution rate of the first 7 principal components was 88.196%, which could reflect the basic characteristics of quantitative traits. Cluster analysis with Euclidean method showed that 30 different Chinese cherry varieties (excellent lines) were preliminarily divided into 4 categories. The fruit quality analysis results obtained in this experiment could be used to explore the genetic variation map of cherry resources in China, and also be used as a reference for new varieties breeding.

The fruit quality of different varieties (lines) of cultivated ginseng fruit in Shilin county was tested and evaluated to provide guidance for the development of ginseng fruit industry. Seven fruit quality indexes of soluble sugar, soluble protein, soluble solid, mineral elements, vitamin C, cellulose and amino acid were determined by using eight main ginseng fruit varieties (lines) of Dayuangguo, Yuangguo No. 1, Yuangguo No. 2, Yuangguo No. 3, Shiyou No. 1, Shiyou No. 2, Shiyou No. 3 and Ruiyu cultivated in the field of Shilin county. By multiple comparison of quality indexes of Panax ginseng fruit, it was found that the content of soluble sugar in Yuanguo No. 2 was the highest, while that in Dayuanguo and Yuanguo No. 3 was the lowest; The soluble protein content of Shiyou No. 2 was the highest, and that of Shiyou No. 1 and Ruiyu was the lowest; The content of soluble solids of Yuanguo No. 2 was the highest, while that of big round fruit was the lowest; Shiyou No. 3 has the highest content of vitamin C and Yuanguo No. 3 has the lowest content; The crude fiber content of Yuanguo No. 2 was the highest, and that of Shiyou No. 1 was the lowest; The content of trace elements in Yuanguo No. 2 was the highest, while that in Yuanguo No. 3 was the lowest; The amino acid content of big round fruit was the highest, and that of Shiyou No. 2 was the lowest. There were significant correlations between the quality indicators of different varieties (lines), among which soluble sugar and soluble solids were significantly correlated with each other (P<0.05). The principal component analysis of 6 quality indicators was carried out, and the cumulative contribution of the first three principal components reached 83.955%, which could reflect most of the information of the original quality index. The resulting comprehensive evaluation system was established to evaluate eight different varieties (lines) of ginseng fruit. In conclusion, the above eight ginseng fruit varieties (lines) all contain rich nutritional components, among which Yuanguo No. 2 has the best comprehensive quality, and can be selected as the parent material for the main variety or new germplasm creation.

In order to understand the dynamic changes of leaf mineral elements in different key seasonal periods of Sapindus Yuanhua clonal raw material forests, and to reveal the characteristics of nutrient demand of this clonal lineage, we provided a theoretical basis for the scientific development of nutrient management system. The 5 a, 6 a and 7 a years old Sapindus Yuanhua clonal forests in Jianning county, Fujian province were used for the study, and the contents of N, P, K, Ca, S, Mg, Fe, Zn and B were measured at the leaf development stage, the end of inflorescence, the end of anthesis, the beginning of fruit expansion, the fruit color change stage and the fruit ripening stage. The contents of N, P, K, Ca and Mg in the leaves of Yuanhua clonal forest showed a general trend of decreasing, then increasing and then decreasing in different critical periods, and all of them reached the highest in the early stage of fruit expansion. There were significant differences in the contents of N and P in the end of inflorescence and the early stage of fruit expansion. K content at the beginning of fruit expansion was significantly higher than the other key reproductive periods, and there was no significant difference between the rest of the reproductive periods, while Ca content and Mg content were significantly different between the leaf expansion period and the beginning of fruit expansion (P<0.05). Fe and B content showed a tendency of increasing and then decreasing, with Fe content being significantly higher than that of the rest of the reproductive periods during the fruit color change period and B content decreasing dramatically at the end of the flowering period, and being significantly lower than that of the rest of the reproductive periods (P<0.05). Zn and S contents did not change significantly throughout the year. The N, K, P and Mg contents of leaves in the three stand ages were significantly and positively correlated. Ca, K and Fe contents were significantly and positively correlated. S and Zn contents were significantly and negatively correlated, and Zn content was significantly and negatively correlated with S and B contents, respectively. The fruit-sitting period (June to the end of July) can be a suitable period for leaf nutritional diagnosis. Fertilizer application should consider the correlation between elements. At the end of inflorescence extraction, N, P and B fertilizers should be applied early. In the fruit-sitting period, an appropriate amount of fertilizer should be applied, combined with the application of micronutrient fertilizer at the same time.

To maintain the storage quality and prolong the storage period of postharvest bananas, the present study used ‘Guijiao No.6’ as the test material to investigate the 1-hexanol effect on the fruit quality and storability of the postharvest bananas under room temperature storage conditions. Banana fruits with intact fruit appearance and similar ripeness and size were selected and randomly divided into control and treatment groups. The control and treatment groups were treated with water and 0.1% (V/V) aqueous solution of 1-hexanol, respectively. Then, the bananas were removed to air-dry and packaged in polyethylene bags with a zipper. Finally, the samples were stored at 25 ℃ for 15 days. Changes in firmness, soluble solids, respiration intensity, condition index, malondialdehyde (MDA), membrane permeability, and PLD activity were measured every 3 days, and changes in PLDγ and PLDζ expression during storage were analyzed by quantitative real-time PCR (qRT-PCR). The results showed that 0.1% (V/V) 1-hexanol significantly (P<0.05) delayed the process of postharvest banana fruit softening, and the delaying effect was highly (P<0.01) significant on days 9 and 12. From day 9, 1-hexanol highly significantly inhibited the rise in total soluble solids and condition index. From day 6, 1-hexanol significantly inhibited respiration, where the peak respiration was reached on day 9 and was highly significantly reduced by 33.93% compared to the control. After day 12, compared with the control group, 1-hexanol highly significantly reduced the rise of MDA content and membrane permeability, by 26.70% and 62.20% on day 15, respectively. In addition, 1-hexanol significantly inhibited PLD activity, especially from 6 to 12 days, and the inhibition was highly significant (P<0.01). At day 15, compared with the control group, 1-hexanol highly significantly reduced the banana expression of PLDγ and PLDζ by 72.06% and 33.08%, respectively. In conclusion, 1-hexanol can effectively delay postharvest banana fruit softening, inhibit the respiration and PLD activity, and reduce postharvest fruit disease, thereby inhibiting total soluble solids, MDA production, and increased membrane permeability, and inhibiting PLDγ and PLDζ expression, thereby maintaining postharvest fruit storage quality and extending storage life. Therefore, 1-Hexanol can be used as a fruit preservative, which is not only important for maintaining the post-harvest fruit quality and the development of the banana industry, but also has good application prospects during post-harvest storage.

Insects use floral volatiles as the olfactory cues to locate flowers. Numerous studies have shown that the selection behavior of insects can be impacted by variations in the volatile component concentration of floral varieties. The flower of mango (Mangifera indica L.) rely on insect pollination and susceptible to florivorous pests. However, volatiles in different varieties of mango flowers are relatively insufficient, which is unfavourable to the development of attractants and repellents. Therefore, the volatile floral chemical components in seven mango varieties (M. indica var. Sijimi, M. indica var. Tainong 1, M. indica var. Guire 82, M. indica var. Kaite, M. indica var. Hongmang 6, M. indica var. Hongxiangya, and M. indica var. Jinhuang) were collected using the dynamic headspace adsorption technique. The volatile components were identified and analyzed using gas chromatography-mass spectrometry-mass spectrometry (GC-MS) to compare the composition differences and similarities of the components. The findings indicated that a total of 115 volatile components, comprising 44 terpenes, 30 alkanes, 16 esters, 16 alcohols, five ketones, three aldehydes, and one phenol, were found in the volatiles of the seven species of mango flowers. 82 distinct types of volatile substances were discovered in M. indica var. Sijimi, 49 distinct types of M. indica var. Tainong 1, 46 distinct types of M. indica var. Guire 82, 49 distinct types of M. indica var. Kaite, 60 distinct types of M. indica var. Hongmang 6, 49 distinctive types of M. indica var. Hongxiangya, and 59 distinct types of M. indica var. Jinhuang. Seven species of mango blossoms contained 14 common volatile components: α-pinene, camphene, β-pinene, β-myrcene, 3-carene, α-terpinene, D-limonene, β-ocimene, terpinolene, 1-caryophyllene, germacrene D, o-cymene, benzoic acid, ethyl ester and 2-propyl-1-pentanol; 33 different types of specific components existed, including 24 different types of M. indica var. Sijimi, four different types of M. indica var. Tainong 1, two different types of M. indica var. Jinhuang, one type of M. indica var. Guire 82, M. indica var. Hongmang 6, and M. indica var. Kaite. The volatile compounds of mango flowers had higher relative concentrations of terpenes (46.15%–89.41%), alcohols (2.01%–23.58%), esters (3.34%–14.67%), and alkanes (2.27%–13.75%). The most abundant terpenes were α-pinene, 3-carene and terpinolene, the most abundant alcohols was linalool. The most abundant esters were benzoic acid, ethyl ester, and the most abundant alkanes were cyclohexasiloxane, dodecamethyl. The flower volatilesof M. indica var. Sijimi and M. indica var. Jinhuang had highest similarity of 0.862 among seven mango species; and that of M. indica var. Sijimi and M. indica var. Hongxiangya had the lowest similarity of 0.255. The findings would provide a reference for flower-volatile-mediated behavior preference researches in pollination insects and florivorous pests to various mango varieties.

The volatile aroma composition is one of the important indexes for cocoa quality evaluation, and fermentation is the key process that affects the volatile aroma composition of cocoa. To reveal the pattern and differences of the volatile aroma components during cocoa bean fermentation with different genotypes, three types of cocoa (ZYP11-9, STS16, and ZYP6-11) were used as the test materials, and the headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) was used to determine the volatile aroma components during 0-7 days fermentation of cocoa beans, and the relative contents of each component were calculated by peak area normalization. The results showed that a total of 32 volatile aroma compounds were identified during the fermentation of cocoa beans from the three genotypes, among which 9 consensus aroma compounds, including 2,3-butanediol, 2-heptanol, 2-pentanol, 3-methyl-1-butanol, phenylethyl alcohol, linalool, acetic acid, 3-hydroxy-2-butanone, and 2,3,5-trimethylpyrazine, showed significant differences in the relative contents during the fermentation of cocoa beans from different genotypes; PCA analysis showed that there was some correlation between the main aroma components and the aroma characteristics of the fermentation stage, in which 2,3-butanediol, acetic acid, linalool, 3-hydroxy-2-butanone were positively correlated with the aroma characteristics of cocoa beans fermentation stage, and the aroma substances such as 3-methyl-1-butanol, butanolactone, and acetophenone were negatively correlated with the aroma characteristics of the fermentation stage. Therefore, there are differences in the aroma composition and content changes during cocoa fermentation with different genotypes, and there is a correlation between the main aroma components and the fermentation stage, which would provide a reference basis for the breeding and application of high-quality cocoa new cultivars.

Fujian Shuixian belongs to the semi-tree form of tea plant (Camellia sinensis), which is the main variety for processing Wuyi Rock Tea (WRT). At present, there is a widely phenomenon that Shuixian grows naturally (no-pruning) in the management of tea gardens of Wuyishan, and its quality is obviously different from that of pruned Shuixian. In order to clarify the basis and differences of aroma and flavor substances WRT under natural growth and pruning conditions, this study used gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) technology, combined with multivariate statistical analysis, to explore the internal relationship among aroma substances, flavor components and quality of WRT before baking (raw tea) and after baking (finished tea) under natural growth and pruning conditions. The results showed that 261 volatile compounds were identified by GC-MS technology. It reveals that there are obvious differences in aroma substances between raw tea and finished tea of the natural growth Shuixian and pruned Shuixian with the help of principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Compared with the raw tea of pruning Shuixian, the raw tea of natural growth Shuixian showed significant differences in 41 volatile substances (Selection standard: VIP>1, and the FC≥1.5 or the FC≤0.67), in which the relative content of hexyl hexanoate, plant alcohol, isophytol, trans-nerolidol are higher, however, the relative content of β-cedrene, γ-junitene and 2-methoxyfuran are lower. Compared with the finished tea of pruning Shuixian, the finished tea of natural growth Shuixian showed significant differences in 71 volatile substances, such as hexyl hexanoate, methyl caproate, trans-nerolidol, (Z)-β-farnesene, 1-heptanol, 2-heptanone with fruity aroma, and 3-ethyl-1H-pyrrole, 2-formyl-4with baking aroma, whose relative content are higher. There are also great differences in aroma substances between natural growth Shuixian and pruned Shuixian before and after baking, with 91 and 70 different substances respectively. The analysis of aroma activity value (OAV) showed that (E)-3-hexenol, indole, trans-nerolidol, epoxy-β-ionone, (E)-linalool oxide, 2-phenylethanol and methyl salicylate may be important substances for the aroma formation of natural growth Shuixian. Analysis of the main flavor substances showed that there were obvious differences in catechin components and caffeine between natural growth Shuixian and pruned Shuixian. The results of sensory evaluation are consistent with the results of physical and chemical test, showing that natural growth Shuixian with rich fruit fragrance, mellow taste and better quality. This study has a guiding role in scientific management of tea gardens and tea quality control.

In this study, 75% ethanol solution was used to prepare the total extracts of arecanut nut (ANE). Then different fractions of the extracts were prepared by fractionating with petroleum ether (PE-ANE), ethyl acetate (EAC-ANE), n-butanol (BU-ANE) and water (W-ANE) in turn. The inhibition of hypertension from ANE was determined by angiotensin converting enzyme (ACE) activity inhibition assay in vitro. The inhibitory was evaluated with the fraction displayingthe best ACE inhibitory activity by the enzyme kinetic method. In addition, the contents of total polyphenols, total sugar and total protein in each fraction of ANE were determined. The correlation between the contents of the compositions and ACE inhibitory activities was analyzed. Finally, phenoliccomponents in the four fractions were analyzed. The results showed that all the fractions of ANE at different polar parts exhibited ACE inhibitory activity, and EAC-ANE displayed the best. Enzyme kinetics tests showed that the inhibitory effect of EAC-ANE from tender areca on ACE was a mixed type of competitive inhibition and non-competitive inhibition. The correlation analysis showed that the IC₅₀ value of the ACE inhibitory activity of each polar part of ANE was significantly negatively correlated with the content of polyphenols and total sugar. And the absolute value of the correlation coefficient between the IC₅₀ value of ACE inhibitory activity and the polyphenol content reached a very strong correlation (r=-0.912). And a variety of polyphenol components such as catechin, L-epicatechin, procyanidin B₂, protocatechuic acid, and quercetin were identified in the four different polar parts, and the content of polyphenol components in EAC-ANE was the highest. In conclusion, ANE has a certain blood pressure lowering potential, and the ethyl acetate extraction site is the best, and the polyphenol content has a strong correlation with the ACE inhibitory activity of each extract. It can be preliminarily inferred that polyphenols may be the main substances that inhibit the activity of ACE in ANE.

In 2022, a stiff fruit disease was found on seedless litchi in Hainan, which was obviously different from the common litchi diseases in Hainan, such as anthracnose and acid rot. It mainly damaged young fruits. There was no significant change in the appearance of young fruits when the disease occurred. When the fruit was broad bean, the outer peel of the diseased fruit became darker, and the inner peel became irregularly brown after dissection. The fruit no longer expanded, forming fleshless stiff fruit, which was easy to cause serious economic losses. In this study, the pathogen of the disease was isolated, identified, invasion way and rapid detection techniques were studied. The pathogen was identified as Fusarium pernambucanum by morphological identification, ITS, RPB2 and TEF1 gene sequence analysis. The pericarp of seedless litchi fruit at young fruit stage was susceptible to pathogen invasion after being damaged by farming operations, wind, piercing-sucking insects, while the fruit surface was not diseased without wounds. The main invasion period of the pathogen was 3.2-4.8 mm in the longitudinal direction of the fruit. After the fruit was bigger than 9.8 mm, the probability of pathogen invasion gradually decreased. Based on the TUB gene sequence, the specific primers for rapid detection of F. pernambucanum were obtained, and a rapid and efficient molecular detection method based on ordinary PCR was constructed. The detection method is sensitive and efficient, and would provide support for early diagnosis and prevention of seedless litchi stiff fruit disease.

Hypothenemus hampei (Ferrari), a newly invading pest in Hainan in 2019, is a serious threat to coffee production all over the world, posing a major threat to the healthy development of the coffee industry in Hainan and even the whole country. In order to understand the habits of this insect and provide basic data for the prevention and control of this insect in the future, this experiment observed its death-feigning, hunger tolerance ability, and discussed the lethal effect of short-term high temperature on it. The results showed that 24 h without feeding any food had no significant effect on the death-feigning of H. hampei adults. After the treatment at 45 ℃ for 2 h, the proportion and duration of death-feigning of H. hampei adults were significantly increased. The proportion of suspended death reaction was 72.0% and the duration of death-feigning was 320.33 s, which was significantly higher than 43.26 s at 26 ℃. H. hampei had a strong hunger tolerance ability, without providing any food, its longest survival time could reach 204 h, the average survival time was 90.17 h. After short-term high temperature treatment, both treatment temperature and treatment duration significantly affected the survival of adults of H. hampei. With the increase of treatment temperature and treatment duration, the mortality rate increased gradually. The corrected mortality rate was 94.92% after 6 h treatment at 45 ℃, and the mortality rate reached 100% after 12 h. Treatment at 36 ℃ and 39 ℃ for 6 h or less had little effect on the viability of H. hampei, and the mortality rate was 16.94% and 23.73% after 24 h, respectively. The Lt₅₀ of different short-term high temperature treatments decreased with the increase of treatment temperature, and the Lt₅₀ also decreased with the extension of observation time. The shortest Lt₅₀ for 24 h and 48 h after 45 ℃ treatment was 3.11 h and 2.70 h. The longest Lt₅₀ treated at 36 ℃ was 17.85 h and 11.42 h. The LT₅₀ was 39.53 ℃ and 38.66 ℃ for 24 h and 48 h after 6 h of different short-time high temperature treatments, and the LT₅₀ reduced with the extension of observation time.

Dendrobium kingianum belongs to Orchidaceae family, which is widely grown as an ornamental plant in China. In recent years, a blight disease in D. kingianum is observed in Guangdong province, China. This disease infects the stems and leaves of D. kingianum, causing brown rot and plant death. It has a serious impact on production. A fungus was isolated from the diseased plants of D. kingianum. The pathogenicity test showed that this fungus could infect healthy potted plants and cause the disease. The symptoms on inoculated plants were similar to field symptoms. Morphological characteristics of the fungus from the inoculated plants were consistent with that of the original fungus from field samples. The pathogen was identified by both morphological characteristics and β-tubulin (tub) gene sequence analysis. The morphological characteristics of the isolates were similar to Phytophthora palmivora. BLAST results showed both the sequences of two isolates in this study were 99% identical to the sequence of P. palmivora. In the maximum likelihood (ML) tree based on tub gene sequences, the strains in this study clustered with P. palmivora with 100% support. Therefore, P. palmivora was identified as the pathogen of Phytophthora blight on D. kingianum based on morphological characteristics and phylogenetic analysis. This is the first report of P. palmivora causing Phytophthora blight on D. kingianum in China and worldwide. The inhibitory effect of 10 fungicides on P. palmivora was determined using the mycelial growth rate method. The results showed that four fungicides, namely diacetylomyamide, dimethomorph, metalazepine and metalazepine · mancozeb, were the top four toxic to P. palmivora, and the EC₅₀ value was 0.000 03 μg/mL, 0.0628 μg/mL, 0.2381 μg/mL and 0.5457 μg/mL, respectively. It was followed by chlorothalonil, pyrimethole and mancozeb, the EC₅₀ was less than 10 μg/mL. However, the effect of downy mildew hydrochloride and triethylphosphonate was poor, and the EC₅₀ was more than 100 μg/mL. Carbendazim showed no inhibitory effect, the EC₅₀ was more than 1000 μg/mL. The result would provide a theoretical basis for the prevention and control of Phytophthora blight in Dendrobium.

Colletotrichum siamense is the main pathogen of anthracnose in many crops in tropical and subtropical regions. SSK1 is a response regulator protein of the two-component system. Studies have shown that SSK1 in pathogenic fungi is related to the morphogenesis, stress response, drug resistance and pathogenicity of pathogens, but SSK1 homologues have distinct functions in different fungi. In order to understand the function of CsSSK1 in C. siamense, the CsSSK1 gene deletion mutant ΔCsSSK1 and the complement strain ΔCsSSK1 (CsSSK1) were constructed and phenotypically observed. The results showed that the deletion mutant ΔCsSSK1 showed slightly retarded mycelial growth, shorter conidia, lower sporulation and conidial germination rate. ΔCsSSK1 significantly increased the sensitivity of C. siamense to NaCl, sorbitol, sucrose, glucose and Congo red, and the sensitivity to fluconazole and tebuconazole, but decreased the sensitivity to fludioxonil. The pathogenicity of ΔCsSSK1 was significantly reduced. The results showed that CsSSK1 gene was involved in the regulation of C. siamense morphogenesis, response to salt stress, osmotic stress, Congo red stress and fungicide stress, affecting the pathogenicity of C. siamense. The results would lay a foundation for further understanding the function of CsSSK1 gene in C. siamense and analyzing the molecular mechanism of pathogenic fungi response to stress.

The effects of different nitrogen forms on the growth, rhizosphere soil nutrients and soil enzyme activities of cassava variety Huanan 9 (SC9) were studied to provide theoretical basis for the scientific fertilization of cassava in Hunan Province. CK (no nitrogen fertilizer), T₁ (amide nitrogen-urea), T₂ (ammonium nitrogen-ammonium sulfate) and T₃ (nitrate nitrogen-calcium nitrate) were set in the study. The level of soil fertility was the same, and the application rate of nitrogen fertilizer was 180 kg/hm². Effects of different nitrogen forms on plant height, stem diameter, soil nutrients, soil enzyme activity, yield and quality of cassava were studied. Compared with CK, different nitrogen treatments improved plant height, stem diameter, yield and quality of cassava. T₂ had the highest plant height, stem diameter, yield, dry matter rate and starch content, which was significantly higher than that of CK by 13.51%, 32.24%, 61.72%, 6.44%, 19.86%. Nitrogen application changed the nutrient content of rhizosphere soil, and T₂ had the best effect on the nutrient content of cassava rhizosphere soil. The contents of soil organic matter and alkali-hydrolyzable nitrogen in T₂ were higher than those in the other treatments. The content of available potassium in T₂ was higher than that in other treatments at root formation stage and root expansion stage. Compared with CK, nitrogen application increased soil enzyme activity in cassava rhizosphere. With the passage of the growth period, urease activity increased gradually, sucrase activity decreased at first and then increased, catalase and nitrate reductase activity increased at first and then decreased. Among them, the soil sucrase activity in T₂ was the highest. Comprehensive analysis, in Hunan, the effects of different nitrogen forms on cassava growth and soil environment were different. Compared with CK, nitrogen application improved soil fertility, and then improved the growth of aboveground parts of cassava, thus improving the yield and quality of cassava. Among them, the application of ammonium nitrogen fertilizer is more beneficial to the growth and yield of cassava SC9.

The structural characteristics of the rhizosphere bacterial communities of cucumber plants under different proportions of mushroom residue and sawdust were analyzed, and it was found that mushroom residue and sawdust compound substrate could replace conventional commercial matrix peat (CK) cultivation cucumber, which providing a basis for the application of a new substrate cultivation mode. Compared with CK, cucumber cultivated with substrate composed of mushroom residue and sawdust in three different proportions significantly increased its yield, rhizosphere bacterial diversity and richness index, and also affected the metabolic function of rhizosphere bacteria, among which the ratio of mushroom residue to sawdust was 1∶1 (T₂). At the classification level, the proportion of bacterial abundance in Proteobacteria of cucumber plants under the cultivation of mushroom residue and sawdust compound substrate was lower than that of CK, but the proportion of bacterial abundance of Bacteroidota was higher than that of CK, and Bacteroidota was the dominant bacterial phylum shared by mushroom residue and sawdust compound substrate cultivation. At the taxonomic level, unclassified_c__Gammaproteobacteria, Limnobacter and Chujaibacter were the dominant bacterial genera unique to the root system of cucumber plants under CK conditions. Bradyrhizobium, Brevundimonas, and Dokdonella were the dominant bacterial genera with a 1∶3 (T₁) ratio of mushroom residue to sawdust. Under the conditions of 1∶1 (T₂) and 3∶1 (T₃) ratios of mushroom residue to sawdust, respectively, no dominant bacterial genus was found in the rhizosphere of cucumber plants. Through species Venn analysis, the ratio of mushroom residue to sawdust at the species classification level increased the number of rhizobacteria species in cucumber plants under the treatment of 1∶3 (T₁), 1∶1 (T₂) and 3∶1 (T₃), and the richness and diversity of rhizosphere bacteria were improved.