Pokkah boeng disease (PBD) caused by Fusarium complex is one of the major diseases in sugarcane with great impact on the sugarcane industry worldwide. F. sacchari is the prevalent species responsible for PBD in Guangxi. Albeit of a long history of study on the disease, the mechanisms underlying the pathogenicity of the pathogen are still far from clear. To tackle this challenge, we generated an insertional mutant library by transformation of the conidial spores from F. sacchari strain FF001 via Agrobacterium tumefaciens-mediated transformation (ATMT). A total of 3018 hygromycin B-resistant transformants were obtained. Among 12 transformants randomly selected, nine out of 12 transformants carried a single copy of T-DNA, as verified by PCR and Southern blot analysis. The mutants were further screened for virulence variation on detached leaves and 30 mutants with obvious changes in virulence were obtained, including 21 mutants with significantly attenuated and 9 mutants with enhanced virulence. The sites of insertion were determined by thermal asymmetric interlaced PCR (TAIL-PCR) and sequence alignment to the genome sequence of F. sacchari. The majority of the insertions were found in coding regions or promotor regions, with a few in terminator or intergenic regions. It was observed that a few insertions were accompanied with genome fragment deletion, resulting in more than one genes being disrupted in a single insertion. Among the 22 mutated genes with annotated functions were those encoding alpha-mannosidase, neutral amino acid permease, oligomeric Golgi complex component 4, oligopeptide transporter 2, acyl-CoA dehydrogenase, acetoacetyl-CoA synthetase, carbonic anhydrase, Bud 10 protein, kinesin-related protein bimC, zinc finger protein ASD 4, transcription initiation factor TFIID, cutinase G-box binding protein, acriflavine sensitivity control protein ACR-2, nuclear VCP-like protein, heat shock protein 30, thioredoxin, type 2C protein phosphatase (PP2C), exoribonuclease, selenoprotein, DNA polymerase eta, survival factor 1, and aldehyde dehydrogenase, several of which, such as zinc finger protein ASD4 in Magnaporthe oryzae, cutinase G-box binding protein in Ustilaginoidea virens, oligopeptide transporter in Colletotrichum gloeosporioides, PP2C in Fusarium oxysporum, have been implicated as pathogenicity genes. The availability of the diversified pathogenic mutants lay a new foundation for further study on the molecular pathogenic mechanisms of F. sacchari.

In order to screen healthy and excellent introduced sugarcane germplasm, enrich sugarcane hybrid parent resources and obtain excellent sugarcane varieties with direct popularization and application value, 41 foreign sugarcane germplasm materials from France, United States, Barbados, Belize, Jamaica, Romania, Guyana and other countries introduced through Visacane, CIRAD, France, responsible for introduction, export and quarantine of sugarcane germplasm from different countries, were planted in quarantine house for two sugarcane growth cycles. During the period, the quarantine disease such as sugarcane white stripe disease, Fiji disease and gummosis disease were monitored. After qualified quarantine, the natural disease occurrence, agronomic traits, cane yield and sugar content were investigated in field experiment. The 41 introduced foreign sugarcane germplasm entries had quarantine diseases and pests. In the field natural disease test, there were nine sugarcane germplasms B03-224, B03-876, FG08-057, FG08-757, FG09-128, FG09-331, FG09-367, FG09-538 and FR89-746 with good disease resistance, which could be used as disease resistant parents. Eight high sugar germplasms with high sugar content, B03-224, BBZ88-343, BJ99-32, BR08-004, CP04-1844, CP05-1526, FG06-691 and FG09-367, were evaluated as 1 grade, which could be used as high sugar parent. Five high-yield germplasms with high yield, BZ93-855, CP00-1446, FG09-124, FG09-346 and FR90-881, were evaluated as grade 1 and could be used as high-yield parents. Eleven germplasms, B03-224, BBZ93-855, BJ99-106, CP00-1446, CP05-1526, FG04-333, FG06-691, FG07-338, FG09-124, FG09-128 and FG09-367, with high-yield and excellent agronomic characters, entered the next round of comparative test to continue screening. In order to select sugarcane germplasms with high yield, high sugar and disease resistance that can adapt to the ecological environment of Guangxi for direct planting, four with excellent comprehensive performance, B03-224, FG09-128, FG09-367 and CP05-1526, were selected for the further variety comparison test. All sugarcane germplasms were kept in Nanning Sugarcane Germplasm Resources Nursery and Sanya Sugarcane Cross Breeding Base of Guangxi Academy of Agricultural Sciences for further evaluation of drought resistance, cold resistance, and subsequent cross utilization. This study could provide reference for the utilization of sugarcane germplasms introduced from abroad.

Single nucleotide polymorphism (SNP) is widely distributed in plant genomes, which is one of the most abundant form of DNA variation. The molecular markers based on single nucleotide polymorphism are considered to be of great application prospect. Penta-primer amplification re-fractory mutation system (PARMS) is a kind of new genotyping system based on single nucleotide polymorphism (SNP) which has the advantages of high throughput, high accuracy, low cost and short time consuming. The establishment of the PARMS system of pineapple is significant in germplasm identification, gene mapping and marker-assisted selection of pineapple. In this study, three germplasms of significant difference in phenotypes were used as the materials. A specific primer SNP31 was designed based on the resequencing data of 130 germplasm resources. The result revealed SNP31 could effectively group the pineapple germplasm resources, and be used for the subsequent optimization of the system. Reaction volume,primer concentration, method of DNA extracting and template DNA amount were optimized. The results showed that reaction volume, primer concentration and template DNA amount could affect the fluorescence signal value of the genotype signal point. The fluorescence signal value of genotypic signal point decreased when the reaction volume was larger or smaller. The optimal reaction volume was 6 μL. When the concentration of primer and template DNA increased, the fluorescence signal value of genotype signal point increased. The optimal concentration of primer and template DNA was 100 μmol/L and 25 ng/μL, respectively. In addition, different methods of genomic DNA extraction could group well the PARMS-SNP for the three germplasms of pineapple. The optimal PARMS reaction system was as follows:total volume 6 μL, containing 1 μL template DNA (25 ng), 3 μL PARMS mix (2×), 0.45 μL primer mix (100 μmol/L) and 1.55 μL ddH₂O. With the optimal PARMS reaction system, high quality results of PARMS-SNP genotyping was produced on sixty-five pineapple germplasm resources, which indicated that the reaction system was accurate and stable. The establishment of the optimized PARMS genotyping system could provide a basis for the genetic diversity analysis, genetic linkage map construction, gene mapping and marker-assisted selection of pineapple in this study.

Passion fruit is an aromatic tropical fruit of the Passiflorat family Passiflora genus. The peel, accounting for 55% of the whole fresh fruit, is rich in dietary fiber, vitamins, anthocyanins, pectin and other active ingredients. The industrial utilization has high environmental value and commercial potential. To make full use of the waste passion fruit peel resources and improve the utilization rate of the active components of passion fruit peel, microwave-assisted, ultrasonic-assisted and microbial fermentation technologies were used to successively extract the effective components such as pectin, anthocyanins and dietary fiber from passion fruit peel, and the process conditions of each stage of co-production were optimized by the response surface methodology. The optimal extraction conditions for pectin from passion fruit peel were liquid to solid ratio of 65∶1 (mL/g), pH 2.5, microwave power of 450 W, and microwave time of 5.0 min. The optimal extraction condition for anthocyanins from the residue after extracted pectin were ethanol concentration 50%, liquid to material ratio 60∶1 (mL/g), pH 3.5, ultrasonic power 550 W, ultrasonic time 35 min. The optimal extraction condition for dietary fiber from the residue after extracted pectin and anthocyanin was liquid to material ratio 12.5∶1 (mL/g), inoculum amount 5.0%, the fermentation temperature was 35 ℃, and the fermentation time was 20 h. Under the process condition, the yield of pectin, anthocyanin and dietary fiber in passion fruit peel was 12.45%±0.06%, 1.21%±0.03% and 55.56%±0.05%, respectively. Compared with single producing, the yield of anthocyanins and dietary fiber from co-produce was reduced by 15.39% and 11.43%, but the material was economized by co-produce, and three products could be obtained through technology process at the same time. Compared with single producing pectin, anthocyanins and dietary fiber, the benefit of co-produce was approximately increased by 2.67, 14.99 and 0.31 times correspondingly. It reduces resources waste, environmental pollution, extractant consumption, and increase the income of farmers.

The technology of planting Sesuvium portulacastrum for ecological restoration has been widely used in Fujian and other places with remarkable results. It is worth discussing whether it can be applied in Hangzhou Bay with eutrophication. The rapid growth of S. portulacastrum can absorb large amounts of nitrogen and phosphorus and remove excess nutrients from water. In this paper, the ecological adaptability of S. portulacastrum to different light intensity, salinity and temperature were studied, and the low temperature and high salinity stress and compound stress were studied further, which is to meet the actual restoration necessary of Hangzhou Bay wetland or water area using S. portulacastrum. S. portulacastrum had a wide tolerance to light intensity, with a light saturation point of 300 μmol/(m²·s), and was intolerant to high light irradiation, but the inhibition of high light on relative electron transfer efficiency was low. S. portulacastrum had a wide range of tolerance to salinity, which could grow in low salinity or fresh water, and the species can tolerate high salt stress more than 25. It grew better in salinity 15 than those of all treatment groups (P<0.05). Appropriate salt treatment could promote root growth and development. S. portulacastrum could tolerate a wide range of temperature expect for very low temperature. S. portulacastrum still maintained a high growth rate in high temperature, 25 ℃ was the best status for the species growth, and the growth rate was significantly higher than that of other treatment group (P<0.05) with accumulation of dry matter faster, plant height, root length grew rapidly and leaf number increased. Low temperature stress in 5 ℃ was reversible and the plant could grow when temperature roise. But the plant was completely dead under 0 ℃ in about 24 days. The plants in the fresh water group died at 5 ℃, but the survival rate of salinity 15 was 100% at 25 ℃, the survival rate of salinity 25 was 40% at 0 ℃, and all plants in the fresh water group died, indicating that salt stress may be beneficial to plant resistance to low temperature stress. Outdoor experiments showed that S. portulacastrum could adapt to Hangzhou Bay climate, but the effect of extreme weather needs to be considered. In conclusion, the ecological restoration technology of S. portulacastrum could be applied in Hangzhou Bay basically, and the study would provide a new idea for the ecological restoration of Hangzhou Bay.

To clarify the adaptability of Oligonychus biharensis in different main rubber varieties, the development and reproduction of O. biharensis in six rubber varieties, 'Reyan 73397' 'Reyan 72059' 'Reken 628' 'Dafeng 95' 'PR107' and 'RRIM600' were observed by biological methods, and the experimental population life table was established. Different rubber varieties had significant effects on the development and reproduction of O. biharensis. The whole generation duration of O. biharensis was the shortest in 'RRIM600' and the longest in 'PR107', which was 11.40 d and 12.07 d, respectively. The survival rate of all mite stage was the highest after feeding on 'Reken 628', which was 100%. The value was 75% when feeding on 'PR107'. The longevity of female O. biharensis mites was prolonged and O. biharensis had large number of fecundity per female when feeding on 'Reken 628' and 'RRIM600', which wase 12.23 d and 28.66 eggs, 10.31 d and 29.56 eggs, respectively. There was no significant difference in the sex ratio of F₁ generation of O. biharensis on different rubber varieties. According to the parameters of population life table, the net reproductive rate of O. biharensis was the largest in 'RRIM600' and 'Reken 628', which was 29.570 and 28.640, respectively. The intrinsic rate of increase and finite rate of increase of O. biharensis were the lowest in 'PR107', which was 0.257 and 1.292. The mean generation time and double population time were the longest in 'PR107', which was 9.539 and 2.702, respectively. In a comprehensive view, it showed that O. biharensis had a good adaptability when feeding on 'RRIM600' and 'Reken 628', while it went against the population growth of O. biharensis in 'PR107'.

Rice blast is the major disease that threatens rice production in Fujian. Investigation of the variation of avrirulence genes (AVRs) in the field population of rice blast fungus could facilitate the release and rotation of the resistance varieties, and subsequently prevent the burst of rice blast disease caused by the loss of rice blast resistance. We firstly investigated the pathogenicity and genetic variation of a field population consisting of 113 Magnaporthe oryzae monoconidial strains isolated from three different major rice planting regions in Fujian province. For pathogenicity and virulence assays of the strains, spray inoculation was performed using 24 monogenic lines carrying 24 different major blast resistance genes. The results showed that the pathogenicity frequency of strains isolated from Jianyang, Ninghua and Shanghang were ranged from 12.50% to 95.83%, 29.17% to 100% and 4.55% to 86.36%, respectively. All strains showed strong pathogenicity toward the monogenic lines carrying Pik^s、Pib、Pi3 and Pi12, while strains isolated from Jianyang and Ninghua also showed strong pathogenicigy toward the monogenic lines carrying other 12 resistance genes, including Pia, Pii, Piz, Pita, Pit, Pis^h, Pi5, Pi7, Pi19, Pi20, Pita² and Pi11. To investigate the genetic variation of AVR genes in the above strains, we performed genotyping of 8 AVR genes: Avr-Pia, Avr-Pib, Avr-Pik, Avr-Piz-t, Avr-Pii, Avr-Pi9, Avr-Pi54, and Avr-Co39. As expected, Avr-Co39 was absent in all the strains, indicating that all the strains collected in the three regions of Fujian province did not carry the AVR gene. The frequency of Avr-Pib in the 113 strains was also very low (37.17%). However, the ratio was much higher than that of the functional Avr-Pib (4.32%), indicating some loss-of-function mutations of Avr-Pib in the Fujian field population. We compared the sequence of selected AVR genes amplified from some field isolates to the reference sequences, and found variation in the promoter region of Avr-Pib, as well as Avr-Pik and Avr-Piz-t. Besides, we also found mutations in the coding region of Avr-Pik and Avr-Pita amplified from some of the Fujian field isolates. Our results suggested that rice cultivars carrying Pi1, Piz⁵, Pi9, Pik, Pik^h and Pik^m still could be used in Fujian Province.

Dendrobium is a class of ornamental plants native to tropical regions, suitable for cultivation in high temperature and high humidity environment, and susceptible to low temperature stress. To investigate the physiological response and cold tolerance of Dendrobium to low temperature stress, Dendrobium 'Sonia Hiasakul' mature (SH) were treated in temperature 15 ℃, 10 ℃ and 5 ℃ for 1 h, 2 h, 4 h, 8 h, and the physiological indexes and morphological changes of SH were surveyed 1 d, 2 d, 4 d, 8 d and 16 d after. The changes of physiological indexes included soluble protein, soluble sugar, free proline, malondialdehyde (MDA), chlorophyll content, electrical conductivity and the defoliation rate of the treated plants. Based on the relative conductivity of different temperature treatments, a Logistic equation was fitted to calculate the half-lethal temperature (LT₅₀) of SH, and a correlation analysis between the half-lethal temperature at low temperature (LT₅₀) and the physiological indexes of cold resistance was conducted, with the aim to investigate the morphological and physiological response characteristics of SH under different low temperature environment and to understand the pattern of its growth and development. The electrical conductivity, free proline, malondialdehyde (MDA) content and the defoliation rate of SH increased significantly with the extension of the stress time and the soluble protein and soluble sugar content fluctuated continuously, in a state of rising, falling, then rising again. The chlorophyll content decreased gradually, reaching the lowest 0.2534 mg/g treated at 5 ℃ for 16 d. Correlation analysis revealed that the free proline, malondialdehyde (MDA), defoliation rate and semi-lethal temperature were all highly significantly correlated and chlorophyll content and semi-lethal temperature were significantly correlated, and it was speculated that the content of the physiological indicators was related to the cold resistance characteristics of SH. The study would provide a theoretical basis for determining the cold tolerance identification index and dealing with cold damage in SH, and lay a foundation for further research on the resistance of Dendrobium hybrids to low temperature damage.

In order to determine the quality of soil fertility of bamboo species in coastal sandy land and guide the construction and management of bamboo shelter forest in coastal sandy land, the difference of soil physical and chemical properties of different bamboo forests in coastal sandy land and evaluate the soil quality were studied. Eight bamboo species in coastal sandy land were selected from Chishan State-owned Farm in Dongshan County, Fujian Province. The physical and chemical properties of the 0-20 cm soil layer of each bamboo species were determined. One-way ANOVA analysis was conducted to test the significance of each index, and principal component analysis weighted comprehensive index method and fuzzy mathematics were used to comprehensively evaluate the soil fertility quality of different bamboo species. Soil moisture content, soil density, capillary porosity, non-capillary porosity and total soil porosity of Oligostachyum lubricum were significantly different from those of other bamboo forest (P<0.05). The average pH of soil ranged from 5.01 to 7.36, and there was no significant difference in the pH of other bamboo forests except the neutral soil pH of Bambusa oldhamii (P>0.05). The average soil organic from 4.43-11.06 g/kg, Pseudosasa amabilis var. convexa was significantly lower than that of other bamboo forests. The average range of soil total potassium and available potassium was 4.59-79.33 g/kg and 0.78-43.11 mg/kg. The average range of soil total nitrogen and total phosphorus was 0.47-2.42 g/kg and 0.09-0.37 g/kg, and soil electrical conductivity, total availability and quick availability of N, P, K. had significant differences among different bamboo forests (P<0.05). The order of soil fertility quality index order of the eight bamboo species was P. japonica>O. lubricum>Phyllostachys nidularia f. farcata>B. oldhamii>Dendrocalamus minor var. amoenus>B. tuldoides 'Swollenintrnode'>B. eutuldoides var. viridi-vittata>P. amabilis var. convexa. The physical and chemical properties and total soil quality of bamboo shelterbelt in coastal sandy land were significantly affected by the types of bamboo stands. P. japonica could effectively improve soil quality, but the effect of P. amabilis var. convexa. on soil improvement was not obvious. Bamboo species and planting methods should be selected rationally for the construction and management of bamboo shelterbelt in coastal sandy land.

Cassava is an important food crop in tropical regions. Cassava bacterial blight caused by Xanthomonas phoseoli pv. manihotis (Xpm) is an important disease of cassava. Excavating and identifying the genes of cassava resistance to Xpm and analyzing its disease resistance mechanism are beneficial to the development of cassava disease-resistant germplasm. Plant heat shock transcription factors (Hsfs) play an important role in the process of plants resisting biotic and abiotic stresses. In this study, the full-length heat shock protein transcription factor gene MeHsfB3a was cloned from cassava cultivar 'Huanan 8' ('SC8') by RT-PCR technology. Bioinformatics analysis found that MeHsfB3a contained two exons and one intron, with a full length of 729 bp, encoding 242 amino acids with 27.9 kDa and pI=7.59. The theoretical instability coefficient was 56.86, which is an unstable protein, and the average hydrophilicity index was-0.880, indicating that the protein has good water solubility, and the fat solubility index was 65.98. The protein was predicted to localize in the nucleus. qRT-PCR analysis found that MeHsfB3a was expressed in young leaves, mature leaves, terminal buds, petioles, tuberous roots and fibrous roots, with the highest expression in mature leaves and less in other organs. The expression of MeHsfB3a was analyzed after 0 h, 3 h, 6 h, 1 d, 3 d and 6 d after infection of cassava 'SC8' leaves by pathogen XpmHN11, and it was found that the expression of this gene was significantly increased after 1 d. This indicated that MeHsfB3a was involved in the response of 'SC8' cassava to XpmHN11. The MeHsfB3a gene of cassava 'SC8' was silenced by the VIGS technology, and the gene silencing efficiency reached 68.26%-82.44%. The leaves of silent plants were inoculated with XpmHN11, and the disease incidence was analyzed on 0 d, 3 d, and 6 d of inoculation, and it was found that the area of disease spots of the silent plants was significantly higher than that of the control. This study identified the heat shock protein transcription factor gene MeHsfB3a involved in the process of cassava resistance to XpmHN11, which would help to further analyze the disease resistance mechanism of cassava to cassava bacterial blight.