Rubber tree is an important economic tree species. In order to explore the reasonable amount of fertilization in rubber plantations, field experiments with different nitrogen fertilizer dosages were set up to clarify the nitrogen transportion characteristics of rubber plantations after mid- and late-stage fertilization. Four treatments were set up: ① blank control (CK), no fertilization; ② conventional fertilization (C, total fertilization 2 kg/plant, early stage∶middle stage∶late stage=5∶3∶2); ③ reduced fertilization (J, total fertilization 1.6 kg/plant, early stage : mid dle stage∶late stage=5∶3∶2), and the reduction of fertilization is equivalent to a 20% reduction in conventional fertilization; ④ simultaneous fertilization (T, total fertilization 1.6 kg/plant, early stage∶middle stage∶late stage=3∶3∶2). The results showed that the characteristics of soil nitrogen transportion in rubber plantations with different fer tilization treatments were different, mainly vertical transportion, and horizontal transportion fluctuated significantly within 5 cm, and there was no obvious change with the increase of horizontal distance. The ammonium nitrogen in the mid-term fertilization mainly transported to 40-60 cm, while the ammonium nitrogen in the later fertilization mainly stayed at 0-20 cm. The trend of inorganic nitrogen was consistent with that of ammonium nitrogen, the main form of soil inorganic nitrogen under different fertilization treatments was ammonium nitrogen. The transportation ability of both ammonium and nitrate nitrogen was reduced and the transportation to deep soil was reduced in the late fertilization. Therefore, adjusting the amount and time of fertilization is beneficial to improving the utilization rate of nitrogen fertilizer in rubber plantations and reduce nitrogen loss.

FRK1 is a marker gene downstream of the innate immunity in Arabidopsis thaliana (At), and FRKI's expression implies the initiation of the PTI pathway. This experiment screened eight FRK1-like genes from the cassava local genomic database via the Blastp method. Bioinformatics analysis reveals that all the eight FRK1-like genes encode receptor-like protein kinases with amino acid lengths between 804-921 aa and an average protein sequence length of 863 aa. The eight genes were found unevenly distributed on cassava chromosomes, mainly on chromosomes 11 and 4. The analysis of the gene structures showed that the eight genes could be classified into two groups, which in agreement with the results of the evolutionary tree analysis. Based on the location of the conserved motifs and the length of amino acid residues, it was found that MeFRK1, MeFRK4 and MeFRK5 shared three conserved motifs with AtFRK1, and the length of the conserved motifs was between 50 and 250 aa. By comparing with AtFRK1 and factoring in the results of protein motifs, chromosome positioning and evolutionary relationships, MeFRK1 was identified as a marker gene downstream of the innate immunity in the cassava genome. The experiment was conducted on cassava SC8 group-cultured seedlings, and the expression of MeFRK1 gene in leaves was measured by fluorescence quantitative PCR after treatment with the hormones SA, JA and the pathogenic bacteria Xam, respectively. The experiment unveiled that the expression of MeFRK1 gene after the treatment of hormones SA, JA and Xam all demonstrated an increasing trend followed by a decreasing one. After the treatment of the hormone SA and JA, the expression of MeFRK1 gene both peaked at 15 min, with the expression under SA treatment slightly higher than that of JA. While after the treatment of Xam, the expression peaked at 4 d at which time the expression was significantly higher than that of SA and JA treatments, 2.84 times that of the SA treatment and 3.06 times that of the JA treatment. It is evident that MeFRK1 has a positive regulatory effect in response to SA and JA signaling pathways for a short period of time, and the response is relatively rapid. Pathogenic Xam could better induce the expression of MeFRKI gene, thus improving the resistance of cassava to pathogenic bacteria Xam. The results may lay the foundation for further establishment of a molecular system for cassava disease resistance.

Cassava (Manihot esculenta Crantz) is an important food and bioenergy crop globally. One of the most significant methods for germplasm development and variety selection is hybridization. However, a series of problems including difficulty in seed germination hinder severely the development of new cultivars. Thus, in present study, seed dormancy characteristics as well as dormancy breaking methods were investigated with freshly harvested natural hybrid seeds of SC124. The cassava seeds are oval and contain a seed coat, endosperm and embryo according to the observation of anatomy and scanning electron microscopy. The outer epidermis is smooth and contains epidermal layer, spongy parenchma and densely arranged palisade parenchma from outside to the inside. The seed coat and seed caruncle slow down the water absorption of cassava seeds, while the primary reason for inducing seed dormancy is the mechanical hindrance of seed coat and the existence of the inhibitor, which could be classified as physiological dormancy. Treatments by scarified seed micropyle, removing seed coat and scarified seed micropyle + two alternating cycles of moist cold temperature (0 ℃) for 2 h followed by moist warm temperature (30 ℃) for 2 h could effectively break seed dormancy and improve seed germination percentage. Treatment by scarified seed micropyle was the most effective methods, which promoted seed germination from 2% to 88% and germination rate was also the fastest. The optimum temperature for germination of cassava seeds was 35 ℃, and the germination percentage and germination index was 88% and 36.6, respectively. The research could provide scientific basis for understanding seed structure, seed dormancy characteristics and the best broken method for cassava seeds in production practice, and also provide a theoretical reference for the expression of excellent traits of cassava hybrid offspring.

The current preservation methods of Phallus rubrovolvatus not only result in short shelf life and rapid quality deterioration but also greatly limit its market sales. Consequently, exploring the characteristics of quality deterioration during the preservation of P. rubrovolvatus and corresponding key control points is essential to slow down the deterioration and prolong the shelf life. In this study, the samples were processed with no treatment (control), silica gel desiccant treatment, ozone and silica gel desiccant treatment, silica gel desiccant and preservative paper treatment, and silica gel desiccant, active paper, and preservative paper treatment, respectively. After treatment, the samples were preserved at low temperature (4 ℃) and normal temperature (25 ℃), respectively, and were collected regularly for sensory evaluation, enzyme activity determination, and texture determination. The quality deterioration characteristics and key control points of P. rubrovolvatus during preservation were revealed based on the changes in sensory indexes decay rate, weight loss ratio, color and odor, the changes in enzyme activity of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and chitinase, etc., and the changes in texture indexes such as hardness, elasticity, and chewability. The results showed that silica gel desiccant treatment at normal temperature, ozone and silica gel desiccant treatment at low temperature had a significant effect on maintaining the weight of P. rubrovolvatus, with the 4.82% and 7.36% at low temperature, respectively, followed by ozone and silica gel desiccant treatment at normal temperature, silica gel desiccant treatment at low temperature with a weight loss ratio of 7.66% and 7.42%, respectively. With ozone and silica gel desiccant treatment, the decay rate was 13% at normal temperature at 2 d and 0% at low temperature at 22 d. The sensory evaluation under ozone and silica gel desiccant treatment demonstrated that the yellowing degree and odor deterioration score were the lowest, and the changes in yellowing degree and odor intensity were slow. According to the texture determination, ozone and silica gel desiccant treatment presented the highest comprehensive score and had the best inhibitory effect on deterioration-related enzymes, which effectively prolonged the shelf life of P. rubrovolvatus from 5 d to 20 d. Based on the results, ozone treatment at the initial stage can effectively reduce the species and quantity of miscellaneous bacteria on the surface of fruiting bodies of P. rubrovolvatus, and slow down the proliferation rate of miscellaneous bacteria during subsequent preservation, thus inhibiting the decay and yellowing of the fruiting bodies of P. rubrovolvatus. In addition, silica gel desiccant treatment can decrease the surface humidity, slow down the damage of chitinase to the cell wall, and inhibit the reproduction of miscellaneous bacteria on the surface, thereby delaying the softening, collapse, and yellowing of P. rubrovolvatus. The best treatment for the preservation of P. rubrovolvatus is ozone and silica gel desiccant treatment at low temperature.

Pleurotus giganteus is a kind of rare edible fungus newly developed in China. It has typical high temperature resistance and plays an important role in the development of edible fungus industry in tropics. With the large-scale cultivation of P. giganteus in tropics, two strains with different fruiting temperature types were selected, which are suitable for cultivation in hot season and cold season respectively, and can effectively ensure the annual supply of the local P. giganteus market. In order to fully understand the nutritional needs and suitable culture conditions of P. giganteus mycelia, the screened high-temperature strain (PG46) and med-temperature strain (PG79) of P. giganteus were used as the materials to compare and analyze the biological characteristics and liquid fermentation conditions with single factor and orthogonal experimental methods, and the dynamic changes of mycelia growth in liquid fermentation were further studied. The experimental data were analyzed by SPSS 26 software. The experiment results of biological characteristics showed that in the single factor experiment, the growth conditions of PG46 and PG79 were basically the same, the optimal carbon source was maltose, the optimal nitrogen sources were yeast extract powder and peptone, the optimal pH was 7, and the optimal temperature was 25-28 ℃. However, the mycelia of PG79 began to suffer from heat stress at 30 ℃, and the colony morphology became irregular. The orthogonal experiment proofed the single factor results, and the impact order of each factor on the mycelia growth of P. giganteus was: nitrogen source > pH > temperature > carbon source. The experimental results of liquid fermentation showed that on the basis of biological characteristics, when the rotating speed was 150 r/min, the liquid volume was 120 mL, and the inoculation amount was 12%, it was more suitable for the mycelia growth of P. giganteus. The mycelial growth of PG46 and PG79 showed a dynamic pattern of "logarithmic growth", and the highest mycelia biomass was obtained at 15 d (0.95 g) and 13 d (1.09 g) respectively. The mycelia biomass of PG79 was always higher than that of PG46, which was consistent with the difference in growth rate between them (PG79>PG46). The study could provide references for the large-scale cultivation of P. giganteus strains with different temperature types, the optimization of heat stress conditions, cross breeding, and the further study of the phenotype and genotype of P. giganteus.

Three-line matching is the main research direction of pepper breeding, identification and development of restorer gene linkage markers in pepper is a difficult problem in restorer line breeding. In this study, the F₂ segregation population was constructed by using 014A and 014C as parents, the segregation ratio of fertility and sterility was 3∶1 by χ² test, indicating that CMS fertility recovery trait of capsicum was controlled by one pair of dominant genes. Using the BSA method to construct the mixed pool of fertile and sterile DNA, the whole genome was re-sequenced and compared with the reference genome, by SNP-index Method and Fisher Test, the cytoplasmic male sterility restorer gene was mapped in the region of 1.44-8.28 Mb at the tip of the chromosome 6. The primers were designed according to the SNP/InDel difference between parents, and the polymorphic primers were screened in both parents and extreme pools, and the molecular markers PP5 and OP59 were obtained. The accuracy of the two markers was 100% in extreme population validation; The marker OP59 was a co-dominant marker, which was located at the candidate gene T459-15819 interval of 17 232 bp. The accuracy of the marker was 100% in the sterile population and 97.21% in the fertile population; PP5 was located 318 bp downstream of the candidate gene T459-15819 of the restorer gene. The accuracy of PP5 was 100% in both sterile and homozygous fertile populations. In this study, we obtained two markers closely linked with the restorer gene, which would lay the foundation for accelerating the selection of CMS restorer lines in pepper.

Cassava is an important food crop and economic crop in the world. Tetranychus urticae is one of the important alien invasive pests and one of the four major cassava pests in China. Breeding and utilization of mite resistant varieties is an important means to realize green integrated pest control. The exploitation and utilization of secondary metabolites with mite resistance function and their regulation genes can effectively breed mite resistant varieties in crops. Flavonoid play an important role in plant defense against phytophagous pests, however, there is little knowledge about the function of flavonoid pathway genes in cassava resistance to mite. Based on this, this study used mite-resistant and mite-susceptible cassava cultivars were used to analyze the flavonoid pathway genes related to plant insect resistance and to analyze the difference of gene expression after mites fed for 1 d and 4 d, respectively. The results showed that, compared with before those mites fed, the relative expression of CHS, PGT1, F3H, FLS, LAR, C3'H and CYP93B_16 genes in the cassava cultivars of BREAD, SC9 and BAR900 showed a trend of first decreasing (1 d) and then increasing (4 d) to the levels before the mites feed (0 d), while the relative expression of the above genes in the mites-resistant cassava cultivars C1115, SC9 and Myanmar showed a trend of first significantly increasing (1 d) and then decreasing (4 d). However, they were all significantly higher than those of the levels before the mites feed (0 d). Further comparison of the differences in the expression of the flavonoids synthesis pathway gene in the mites-resistant and sensitive tapioca cultivars before and after mites was infested, it was found that after the pest of the two-spotted spider mites was harmed for 1 d, the expression of CHS, PGT1, FLS and C3'H in the mites-resistant cassava cultivars was significantly higher than that in the sensitive mites cassava varieties. Correlation analysis showed that the expression of the four genes was significantly and positively correlated with cassava mite resistance. Before mites (0 d) and 4 days after mites infestation, the expression of the above genes in mites-resistant cassava varieties was generally higher than that of the tapioca cultivars. The results speculated that mite-resistant cassava cultivar could activate flavonoid pathways to defend T. urticae infestation. This study would lay a theoretical foundation for further elucidating the molecular mechanism of cassava resistance to mite, and for breeding and creating mite-resistant cassava cultivars.

In order to clearify the potential of entomopathogenic nemotodes (EPNs) on the control of Rhynchophorus ferrugineus, the pathogenucity of Heterorhabditis bacteriophora H06 against all stages of R. ferrugineus and the behavior of the invading red palm weevil larvae was studied using laboratory bioassay methods. The results showed that the mortality of eggs was the highest in all stages after R. ferrugineus was infected by EPNs, and LC₅₀ was 104.85 IJs/mL, followed by 1-2 instar larvae, 3-4 instar larvae and 5-6 instar larvae, LC₅₀ was 165.34 IJs/mL, 215.31 IJs/mL and 292.26 IJs/mL respectively; No significant differences were observed in the sensitivity between 7-10 instar larvae and pupae to EPNs. Among the effects of inoculation site on the mortality of different instar larvae, the mortality of the 3rd instar larvae was the highest when inoculated with spiracle and anus, which was 91.11% and 78.89% respectively, while the lethal rate of inoculation with mouthparts was the highest in the treatment of the 6th and 8th instar larvae. No significant difference presented in the mortality of different instar R. ferrugineus larvae when treated with vent inoculation. The R. ferrugineus body color changed to red or reddish brown, no spontaneous response when touching, and the body wall of R. ferrugineus shrinked after treated by EPNs. When the nematode approached the spiracle of R. ferrugineus larval, it stayed around the spiracle for a moment, and finally entered the insect body, and the number of EPNs successfully invaded was about 33.33%.

During the evolution from lower plants to higher plants, lignification is the key to adapt to the terrestrial environment, while lignin deposition in the cell wall is an important manifestation of lignification, and MYB61 plays an important role in lignin synthesis pathway. In order to explore the molecular mechanism of MYB61 in lignin synthesis of Impatiens chlorosepala and Impatiens uliginosa, MYB61 genes, named IcMYB61 and IuMYB61 in this study, were cloned by using the RT-PCR method. The full-length cDNA was 1035 bp and 1002 bp, encoding 344 aa and 333 aa, containing an intron of 84 bp and 66 bp, respectively. Physicochemical analysis suggested that IcMYB61 and IuMYB61 were unstable hydrophilic protein. Domain analysis of protein showed that IcMYB61 and IuMYB61 contained two typical SANT conserved domains. The comparison of amino acid sequences of MYB61 with that of other species showed that there were highly conserved R2 and R3 regions at the N-terminal, which was speculated to be R2R3-MYB gene. Based on the phylogenetic analysis, it found that IcMYB61 and IuMYB61 were clustered together with I. glandulifera, confirming that the same genus is more closely related. The qPCR showed that IcMYB61 and IuMYB61 were expressed in three different parts of the two periods, and the expression levels were the lowest in roots. In I. chlorosepala, the highest expression of IcMYB61 was in the leaves at the seedling stage, and the highest expression level was in the stem at the mature stage. In I. uliginosa, the expression of IuMYB61 was the highest in the stems of both periods. By measuring the total lignin content in stems and leaves of the two species, it was found that the lignin content of both species was the highest in stems, which was consistent with the expression trend of MYB61. It is speculated that MYB61 mainly regulates the biosynthesis of lignin in the stems of I. chlorosepala and I. uliginosa. The above-mentioned results would provide some basic data and scientific basis for exploring the regulation mechanism of MYB61 on the lignin synthesis of Impatiens and the culture of new varieties.

Beiyuan Tribute tea (BTT), originated from Jian'ou city in Fujian province, is a bright pearl in the history of tea development in China. In this paper, the fresh leaves of Shuixian tea varietiy in Jian'ou were used as the raw materials, cake tea (Dragon and Phoenix cake tea) and loose tea (Nanlu Shuixian tea) were produced by the traditional process of ground tea and the modern process of Oolong tea in Jian'ou of Northern Fujian, respectively. The cake tea was then taken as the material to obtain tea foam and liquid with the Diancha technique. To provide scientific data supporting for the quality and cultural mining of BTT and its Diancha, the content of the main quality components of cake tea and loose tea, as well as the difference in the composition of the tea foam and liquid of cake tea, were compared and analyzed by using a series of biochemical component determination methods and extensive targeted metabolome detection technique. The results showed that there was no significant difference in water content, water extract content and total free amino acids between cake tea and loose tea, but the total polyphenol and caffeine contents of cake tea were significantly higher than that of loose tea, and the contents of theaflavin, thearubin and theafuscin were significantly lower than that of loose tea. Moreover, 1245 common metabolites in 12 categories were detected from the tea liquid and foam of the cake tea, and no specific substances were detected. Through principal component analysis and orthogonal partial least squares discriminant analysis, 26 differential metabolites in 5 categories were screened. Among them, except that the content of astilbin in tea liquid was significantly higher than that in tea foam, 25 differential metabolites in tea foam were significantly higher than that in tea liquid, mainly including lysophosphatidylcholine, lysophosphatidylethanolamine, free fatty acids and other lipid substances. The differential metabolites were mostly reticular, lighter than water, and easy to float on the upper layer of tea liquid, and they were the good foam stabilizers that mainly acting as emulsions and surfactants. Therefore, tea foam can be formed and stably suspended on tea liquid. The results of this study would provide a theoretical basis and scientific support for the industrial development, cultural inheritance and innovation of BTT