Hainan is the southernmost litchi production area in China, but the problems of excessive nutrient input and soil degradation are serious, and the reasonable nutrient input standard is lacking. The study analyzed the current situation of litchi yield, nutrient management and soil fertility in the main producing areas of Hainan, based on the principle of nutrient balance, by quantifying the crop nutrient demand law and the reasonable nitrogen surplus level under the conditions, specifying the upper limit of litchi nutrient usage, proposing the reduction target of nitrogen, phosphorus and potassium nutrient inputs for litchi in Hainan, and analyzing the differences in nutrient management levels of different types of farmers and the impact on soil fertility. The upper limit of nitrogen, phosphorus and potassium dosage of litchi at different yield levels in Qiongshan region was 200 kg/hm², 100 kg/hm², and 260 kg/hm² (<10 t/hm²), 273 kg/hm², 136 kg/hm², 355 kg/hm² (10-20 t/hm²), 439 kg/hm², 220 kg/hm², 571 kg/hm² (20-42 t/hm²), respectively. The phenomenon of excessive fertilizer input of farmers was prominent, and the excess nutrient input was aggravated with the increase of management scale. 60%, 97% and 131% of small farmers, medium operators and large-scale operators were higher than the upper limit of nitrogen fertilizer input. Phosphorus input was 204%, 236%, 258% higher than the upper limit of input; potassium content was 70%, 101% and 119% higher than the upper limit. The fertilization intensity was also significantly higher than the national NPK fertilization level of 70.8%, 189.9%, 123.4%. The surplus of nitrogen, phosphorus and potassium in Hainan litchi orchard was 365 kg/hm², 377 kg/hm² and 542 kg/hm², respectively, and the nutrient use efficiency (NUE) was 34%, 21% and 27%, respectively. A lot of phosphorus was fixed and lost in the soil. There were significant differences in the nutrient management among different types of farmers. Only 1.2% of small farmers were in the range of high N output and low N surplus, while the middle and high operators were all in the range of high N surplus. Soil phosphorus accumulation and soil acidification were prominent problems in the litchi orchards, and 46% of the orchards had soil phosphorus content over 0.96 g/kg, which was at a relatively rich level. 94% of the orchards were acidic soil (pH 4.5-5.5), and 77% of the orchards had low soil quality index (IFI) comprehensive rating. For the current Hainan litchi nutrient inputs unreasonable and soil degradation, the quota system should be adopted and promoted as soon as possible, and the use efficiency of organic and chemical fertilizer should be greatly improved, so as to realize the sustainable development of litchi fruit industry.

In the current study, one newly recorded genera of wild orchids, Neuwiedia Blume, as well as five newly recorded species, including Goodyera brachystegia Hand. -Mazz, Neuwiedia zollingeri var. singapureana (Baker) E. F. de Vogel, Odontochilus drymoglossifolius (Hayata) T. Yukawa, O. saprophyticus (Aver.) Ormerod and O. yakushimensis (Yamam.) T. Yukawa in Fujian province were illustrated. The voucher specimens of the plants are preserved in the Herbarium of Fujian Normal University (FNU). The discovery of the newly recorded orchids has great significance for further studies on the diversity and conservation of Orchidaceae in Fujian, China.

Spathiphyllum Schott is a perennial herb of Araceae, which is an important foliage plant for ornamental. Phenotypic diversity of germplasm resources is the basis of ornamental plants breeding and application. In the current study, 27 important ornamental traits of 20 Spathiphyllum germplasm resources were observed and the phenotypic diversity was analyzed by multivariate statistical analysis methods including variance analysis, correlation analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results of variance analysis showed that the coefficients of variation of the 16 quantitative traits ranged from 27.2% to 69.9%. The plant height, number of shoots, number of leaves, blade width, petiole diameter, spadix length and number of flowers were highly variable, while the plant width and spadix diameter had small variation. Eleven descriptive traits could be divided into 2~4 grades according to the observed characteristics. And the Shannon-Wiener indices of 11 descriptive traits ranged from 0.20 to 1.01, among which the Shannon-Wiener indices of leaf shape were the highest, whereas that of perianth separation and perianth color were the lowest. The hierarchical cluster analysis tree of 27 traits supported that when the euclidean distance was 3, they could be divided into two groups: Group A and Group B. The result of Pearson correlation analysis revealed that the correlation coefficient between 27 traits ranged from -0.72 to 0.91. In Group A, most of the traits were significantly correlated with each other, and the correlation coefficients between bud length and bud width, bud length and inflorescence length were 0.91. In Group B, most of the traits pairs were not significantly correlated. Both hierarchical cluster analysis and principal component analysis supported that the 20 Spathiphyllum germplasm resources could be divided into 2 Groups (Group I and Group II) based on data of 27 traits. Group I contained 7 accessions including S. cannifolium, S. ortgiesii, S. Clevelandii, S. Bright, S. Princess, S. Middle Flower and S. Sensation, and they were taller and had larger leaves, larger spathes, and larger spadixes. Group II was consisted of S. floribundum, S. Coddy Color, S. Water Grass, S. Parrish, S. Mini, S. Vicki Lynn, S. Mojo, S. Tyler Green, S. Crisis, S. Sweet Chico, S. Sweet Claudio, S. Dark Green and S. Sunshine Dream. And the 13 accessions of Group II had more buds and leaves, and were smaller and more compact. The research results could provide a reference for evaluation and breeding of Spathiphyllum germplasm resources.

In recent field survey and specimen examination, eight species of pteridophytes belonging to seven genera in five families are reported as new records in Fujian province, Gymnocarpium oyamense (Baker) Ching, Pronephrium parishii (Beddome) Holttum, Athyrium drepanopterum (Kunze) A. Braun ex Milde, Diplazium okinawaensis Tagawa, D. hainanense Ching, Hymenasplenium excisum (C. Presl) S. Lindsay, Asplenium ensiforme Wallich ex Hooker & Greville and Microsorum membranaceum (D. Don) Ching. Among them, G. oyamense is a newly recorded genus in Fujian province, and P. parishii, A. drepanopterum, D. okinawaensis, D. hainanense and M. membranaceum are newly recorded species in East China.

Iron (Fe) is one of the essential trace mineral elements in plants to maintain normal growth and development that plays an important role in various life processes. Researches towards molecular mechanism of Fe uptake, transport and distribution are mainly focused on the annual model plants. Biological functions of genes towards Fe uptake and transport in fruit trees are still unknown. In this study, 11 ferric reduction oxidase encoding genes (FROs) were isolated and identified from diploid mango Guire 82, named by MiFRO1–MiFRO11. All mango FRO had ten typical motifs except for MiFRO1 lacking Motif2–Motif5. All mango FRO possessed similar tertiary structure, with the exception that MiFRO3 exhibited distinct tertiary structure. The amino acid sequences of FRO from 11 plants shared an overall identity of 42.07%, while mango FRO shared an overall identity of 62.43%. Phylogenetic tree analysis showed that mango FRO were prone to be closely clustered together lonely, which was far away from the homologs of the other ten plants in genetic distance. Quantitative real-time PCR (qRT-PCR) analysis showed that MiFRO3 was the most abundant expressed gene during different parts of Guire 82 mango on the whole. In particular, MiFRO4, MiFRO5, MiFRO8 and MiFRO11 were highly expressed in the leaves of both mature trees and grafted seedlings. MiFRO6 and MiFRO7 were highly expressed in phloem or stem, MiFRO1 and MiFRO10 were highly expressed in young fruits, MiFRO2 and Mi-FRO9 were highly expressed in seedling roots, while MiFRO3 was highly expressed in full bloom flowers. In addition, expression of FRO in mango roots were mainly induced under iron depletion and NaCl stress, respectively, while Mi-FRO3, MiFRO5 and MiFRO8 were significantly reduced under iron toxicity. Expression of MiFRO2, MiFRO5 and Mi-FRO7 were increased under ABA treatment, and MiFRO1 and MiFRO5 were enhanced under PEG treatment. Expression of MiFRO2, MiFRO6 and MiFRO7 were decreased under low temperature (4 ℃). However, FRO changed little under heat stress (45 ℃) in mango roots. This study would provide gene resources to elucidate the molecular mechanisms of Fe uptake and transport in mango, and lay a theoretical foundation to reveal Fe nutrition and high utilization in tropical fruit crops.

The study was aimed to cope with the rapid increase in demand for patchouli [Pogostemon cablin (Blanco) Benth.] and to solve the problems of lack of patchouli medicinal materials, germplasm degradation, confusion of germplasm sources, and vulnerability to diseases and pests. Callus, cluster buds and rooting seedling of patchouli were irradiated with a gradient dose of ⁶⁰Co-γ rays. The appearance and morphology of regenerated plants were observed, the mutated plants were screened, the agronomic traits and physiological and biochemical indicators were measured, and the content of pogostone and patchouli alcohol, the main volatile components, were determined by gas chromatography-mass spectrometry (GC-MS). The results showed that calluses and cluster buds were more sensitive to ⁶⁰Co-γ rays and had higher mortality rate, while rooting seedlings were more tolerant to ⁶⁰Co-γ rays and had lower mortality. The best way to breed mutagenesis is ⁶⁰Co-γ treated rooting seedlings with irradiation doses of 100 Gy with a mutagenesis rate of up to 10%. In this experiment, 29 patchouli variant plants were obtained, which were divided into seven morphological types, namely three-leaf whorls, heteromorphic leaves, deep-split leaves, narrow leaves, coiled leaves, undercoiled leaves and purple leaves. The contents of osmotic conditioning substances [soluble sugar, soluble protein and free proline (Pro)], antioxidant substances [malondialdehyde (MDA), peroxidase (POD), catalase (CAT)], pogostone and patchouli alcohol were compared and analyzed. According to the analysis results of the above determination indicators, 15 potential plants were finally screened, namely: stress-resistant plants with high effective components SY7 and ZY1; environmentally sensitive plants with high effective components SY15, SY18 and XY1; stress-resistant plants SY2, SY6, SY19, YY2, YY9 and XJY1; high active ingredient plants SY10 and SY17; “pogostone-type” patchouli plants SY3 and JY1. Among them, SY7 and ZY1 are new germplasms with double excellent characteristics, and the two “pogostone-type” patchouli plants have application value for solving the problems of the lack of authentic medicinal materials and the degradation of germplasm. In this study, patchouli variant plants bred by the ⁶⁰Co-γ ray irradiation mutagenesis method have the advantages of strong stress resistance and high active ingredients, which would provide mature methods and potential germplasm for patchouli mutagenesis breeding and new variety breeding.

In order to clarify the alleviating effect of heterologous double-root on coffee continuous cropping obstacle, the soil of the continuous cropping obstacle garden of coffee was used to cultivate Caffea liberica, No. 1 and C. canephora, Reyan No. 1 heterologous double-root grafting coffee seedling. The mechanism of heterologous double-root alleviating continuous cropping obstacle was clarified through different root separation ways, and the differences and synergies of heterologous double-root in alleviating continuous cropping obstacle were discussed. Compared with non-rhizosphere soil, the seedling quality index and plant biomass of heterologous double-root coffee or homologous double-root coffee decreased significantly after culturing in rhizosphere soil. After non-rhizosphere soil culture, there were no significant differences in the seedling quality index or plant biomass between heterologous double-root coffee and homologous double-root coffee. The seedling quality index, root biomass of C. liberica and C. canephora, and total plant biomass of heterologous double-root coffee were significantly higher than those of homogenous double-root coffee after rhizosphere soil culture. Continuous cropping obstacle inhibited the growth of coffee, but had more effect on homologous double-root coffee. Heterogenous double-root coffee alleviated the growth obstacle of continuous-cropping coffee by C. liberica roots. The seedlings quality of the heterologous double-root coffee separated root by nylon net was better than that of root undivided or separated root by double pot under continuous cropping, and the root growth of C. canephora was the best in nylon net separation. Root allelochemicals of C. liberica promoted the root growth of C. canephora. There was no significant difference in the seedlings quality of heterologous double-root coffee between root undivided and separated root by double pot, and the C. liberica root growth of root undivided was worse than that of double pot separation. The root growth of C. canephora inhibited the root growth of C. liberica when the heterologous double-root were in contact with each other, but this inhibition was not related to the allelopathic substances in the C. canephora rhizosphere. The root growth of C. liberica had no significant difference in nylon net separation and double pot separation. There was no effect on the root growth of C. liberica with or without the allelopathic substances. of C. canephora. The root system of C. liberica alleviated the continuous cropping obstacle by reducing the inhibition of allelopathic environment and promoting the root growth of C. canephora by its allelopathic substances. The results would provide a theoretical basis for the application of heterologous double-root grafting in the field.

To clarify the effects of short-term high temperature stress on the developmental, reproductive characteristics and offspring fitness of Eotetranychus sexmaculatus females, the females were exposed to 33 ℃, 36 ℃, 39 ℃, 42 ℃, 45 ℃ for 1 h, 2 h, 4 h, respectively. The longevity, fecundity, offspring developmental period and sex ratio of E. sexmaculatus females were observed. The results showed that the oviposition period of E. sexmaculatus was prolonged and the fecundity was increased exposed to from 33 ℃ to 42 ℃ for 1 h, 2 h, 4 h and 45 ℃ for 2 h and 4 h. The population growth of E. sexmaculatus was the most favorable exposed to 39 ℃, the oviposition period was the longest exposed to 39 ℃ for 1 h, which was 12.67 d, and the fecundity of single female was the highest, which was 32.65. The intrinsic rate of increase (r_m) of E. sexmaculatus was the highest exposed to 39 ℃ for 1 and 4 h, which was 0.29, and the population doubling time was shorter, which was 2.42 d and 2.38 d, respectively. Exposed to short-term high temperature stress, there was no significant effect on the offspring sex ratio of E. sexmaculatus. The survival rate of E. sexmaculatus was decreased, the fecundity was decreased, the longevity was prolonged, and the r_m value was decreased exposed to 45 ℃ for 1 h. Therefore, the population development of E. sexmaculatus was inhibited at 45 ℃ high temperature stress for 1 h.

Salt stress is the most prevalent abiotic stress globally, severely affecting crop growth. Rice is an important food crop, it is important to improve the salt tolerance of rice through chemical control technology. To further provide the theoretical basis for the application of hemin to rice cultivation under salt stress, it is important to study the adverse effects of NaCl on rice seedling growth and to understand how hemin regulating the physiological process to alleviate stress. A pot experiment was carried out with the rice varieties Huanghuazhan and Xiangliangyou 900 as the materials. During the three leaves and one heart period, after 48 hours of 5 μmol/L hemin treatment, 50 mmol/L NaCl was applied to the corresponding cultivated soil. Each variety had three treatments, (1) control group: distilled water, (2) S group: 50 mmol/L NaCl solution; and (3) SH group: 50 mmol/L NaCl +5 μmol/L hemin solution. Measurements of seedlings growth characteristics, gas exchange parameters, and physiological indicators were taken after the 3^rd, 6^th, 9^th and 12^nd days after NaCl treatment, respectively. NaCl stress inhibited the seedling growth of the two rice varieties, reduced the photosynthetic rate, and increased reactive oxygen species. Compared with CK, the antioxidant enzymes activities of S group increased significantly in the early stage, but decreased significantly as the extension of stress time. Among them, the inhibitory effect of NaCl stress on Huanghuazhan was stronger than that of Xiangliangyou 900. Compared with NaCl treatment, exogenous hemin increased plant height, stem base width, biomass, total root length, root surface area, root volume, and root tip number of the two rice varieties. Hemin inhibited reactive oxygen species (O₂·^- and H₂O₂) accumulation, decreased malondialdehyde (MDA) content, and electrolyte leakage (EL). The photosynthetic capacity and SPAD were enhanced. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were increased. Meanwhile, the ascorbic acid (AsA) and soluble protein levels were up-regulated in leaves. The results of this experiment indicate that NaCl stress inhibit rice seedlings, and the application of hemin can mitigate the damage caused by NaCl stress on rice seedlings by enhancing the net photosynthetic rate, increasing antioxidant activity or content, and reducing membrane lipid peroxidation.

Bacillus subtilis Czk1 is a rhizosphere antagonist with a very broad-spectrum antagonistic, growth promotion and induction of plant resistance. In order to fully utilize organic nutrients in agricultural wastes and promote biological control of soil-borne plant diseases, Czk1 was used as the research object in this study, chicken manure as the base fertilizer, corn straw, mushroom bran and coconut bran compost were used as the raw materials, and the liquid-solid two-phase fermentation process was adopted. The total number of viable bacteria and the number of spores were determined by the dilution plate colony counting method. The formula, process parameters and culture conditions of Czk1 solid fermentation materials were determined by the single factor and orthogonal experiment method. The results showed that the optimal conditions for solid fermentation of Czk1 are raw material was mushroom bran and chicken manure compost with the inoculated weight of Czk1 at 10%, the added amount of soybean powder at 10%, the water content at 40%, the fermentation temperature at 37 ℃ and the turning once every 72 h. Under the conditions, the total number of viable bacteria in Czk1 strain could reach 8.63×10⁸CFU/g. The number of spores was 8.37×10⁸CFU/g. The best fermentation material was corn straw and chicken manure compost, Czk1 inoculation amount of 10%, adding 5% soybean powder, 40% water content, fermentation temperature of 37 ℃, turning once every 72 h, the total number of viable bacteria in Czk1 inoculation strain could reach 6.53×10⁸CFU/g. The number of spores was 5.97×10⁸CFU/g. The total number of viable bacteria and the number of spores of Czk1 strain could reach 8.70×10⁸CFU/g and 6.90×10⁸CFU/g, respectively, when 30% mushroom bran was added. The physical and chemical properties of four fermentation biological fertilizer raw materials were determined, and significant differences were observed in their organic matter content and carbon to nitrogen ratio. Among them, chicken manure had the highest pH, total phosphorus, and total potassium content, while the carbon to nitrogen ratio was the lowest. The total content of nitrogen, phosphorus, and potassium was higher than that of corn straw, coconut bran, and mushroom bran; Corn straw has the highest electrical conductivity and organic matter content as the raw material; Coconut bran has the highest total nitrogen content, while mushroom bran has the highest carbon to nitrogen ratio. The seed germination index of bio-organic fertilizer with different combinations of chicken manure, mushroom bran, corn straw, and coconut bran is greater than 80%. Therefore, high quality bioorganic fertilizer can be prepared from agricultural waste by selecting suitable fermentation production conditions. B. subtilis Czk1 has good development and utilization value.