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.

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.

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.

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.

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.

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.

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.

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 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.