Codon bias is an important factor affecting gene expression, and it is also one of the key clues to reflect gene evolution. Orchidaceae plants are the "flagship" group in plant protection, and most species have medicinal and ornamental values, but seeds are not easy to germinate. ABI3 (abscisic acid insensitive 3) gene is the central regulator of ABA signal transduction, involved in seed development and dormancy processes, and is the key factor to regulate plant seed germination. Therefore, in-depth study of codon bias of orchid ABI3 gene can lay a foundation for analyzing the function of the gene and optimizing the codon composition. Using Arabidopsis thaliana ABI3 gene as a probe, 45 Orchidaceae ABI3 genes were screened from the public database (NCBI), and the codon use patterns and preferences were analyzed by bioinformatics programs such as CodonW, SPSS and MEGA. The ENC (effective number of codon) value of the genes ranged from 40.84 to 58.46, of which 82.2% was greater than 52. The average value of CAI (codon adaptation index) was 0.203, far less than 1, indicating that the codon usage bias of ABI3 gene was relatively weak. Neutral plot analysis showed that the slope of the regression curve between GC₁₂ and GC₃ was 0.6103, R²=0.7928 (P<0.05), indicating that the base composition has an important influence on codon bias. In ENC plot analysis, the ENC value of all genes was lower than the expected value, but the difference was small, indicating that the codon of orchid ABI3 gene is mainly affected by base mutation and other factors such as selection pressure. Parity preference analysis showed that most genes were distributed in the right region of the plan, and the use frequency of A/T (U) at codon 3 was higher than that of G/C. Through RSCU and ΔRSCU analysis, 26 optimal codons were identified, including 14 codons ending in A/T (U) and 10 codons ending in T (U), indicating that ABI3 gene of orchid plants relatively prefers to use codons ending in A/T (U), especially codons ending in T (U), which is different from that of most monocotyledonous plants. This study may provide a theoretical basis for the phylogenetic and functional elucidation of ABI3 genes in Orchidaceae and for improving ABI3 gene expression efficiency, as well as facilitating codon biology in plants and the improvement of exogenous genes.

In order to understand the characteristics of the wild seed plant system in Nanning and provide a scientific basis for the conservation and rational development and utilization of biodiversity in the region, the author investigated and analyzed its plant resources, compiled a list of wild seed plants in Nanning using statistical methods of literature collection, line survey and sample survey, judged their affinities with 15 neighboring areas using cluster analysis and principal component analysis, and analyzed their systemic characteristics, the results show that: there are 3574 species of wild seed plants in 197 families and 1114 genera in the region, 24 species of 14 genera in 8 families of gymnosperms and 3552 species of 1100 genera in 189 families of angiosperms. The ratio of the number of seed plant families, genera and species in Guangxi is 77.87%, 60.02% and 42.90% respectively, indicating that the wild seed plants in Nanning are rich and diverse. The ratio of large families is 27.41%, and the number of species contained is 78.44%, which is the main component of the system. Monospecific and oligospecific genera accounted for 85.28% of the total number of genera, but the number of species contained in medium and multiple genera accounted for 51.65% of the total number of species, indicating that the family is rich in species but less differentiated. There are 14 genus-level distribution area types in the region, with rich and complex geographical components, among which tropical components account for 69.55% of the total number of genera and temperate components account for 22.16%, showing obvious tropical attributes and some temperate attributes. 223 rare and endangered plants in the region, rich in species, including Orchidaceae, Camellia petelotii and other endemic plant species, the regional characteristics of Guangxi plants are obvious, and the protection value is high. The system belongs to the Beibu Gulf region and the Yunnan-Guizhou-Guangxi region, and its R/T value (3.08) is in the middle compared with the neighboring regions, similar to the R/T value (2.32) of the six counties on the border of Qian-Guizhou, and the largest difference from the R/T value (8.80) of the coastal zone of Beibu Gulf, and the R/T value is negatively correlated with latitude. In terms of genus-level phytogeographic composition, Nanning was the most similar and closely related to Hainan and Xichu, and the most distant from Murray. Overall, the wild seed flora of Nanning is rich in species, ancient in relics, with more rare and endangered plants, showing a tropical and subtropical transitional nature, reflecting the characteristics of the Beibu Gulf and Yunnan-Guizhou-Guizhou flora.

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'.

Soil salinization is one of the important factors limiting crop growth. Cultivating new salt-tolerant rice varieties is of great significance to expand rice planting area. In order to explore the change trend of growth and physiology of different varieties of rice seedlings and clarify the salt tolerance of different rice varieties at seedling stage, five rice varieties were used as the experimental materials. The effects of different concentrations of NaCl (0 mmol/L, 70 mmol/L, 140 mmol/L) on the growth and related physiological indexes were studied at rice seedlings using hydroponic method. The principal component analysis and membership function method were used to comprehensively evaluate the salt tolerance of five rice seedlings. The results showed that under salt stress, salt inhibited the root length, root surface area, root volume, root tip number and root mean diameter of all rice varieties in general. The root growth index values of 'HH11' and 'Nipponbare' changed little. The root length, root volume, root surface area and root tip number of '9311' and 'JX99' were significantly inhibited. The average root tip number of 'HD961' was the largest among the five rice varieties. With the increase of NaCl concentration, the plant height and root activity of each variety showed a gradual downward trend, and the total chlorophyll content, relative conductivity, MDA content, proline content and Na⁺/K⁺ of root showed an overall upward trend, and the root Na⁺ and K⁺ contents showed a trend of first increase and then decrease. Among them, the relative electrical conductivity and proline content of '9311' and 'JX99' increased the most, the MDA and root Na⁺/K⁺ of 'Nipponbare' and 'HH11' increased the least, the plant height of Nipponbare decreased the least, and the root activity of 'HH11' decreased the least under salt stress. Principal component analysis showed that three independent comprehensive indexes explained 94.23% of the changes of 16 single indexes under salt stress. Among them, root length, root volume, root tip number, total chlorophyll content, malondialdehyde content and electrical conductivity could be used as the main factors to evaluate salt tolerance at seedling stage, and K⁺, Na⁺/K⁺ and plant height could be used as the secondary factors to evaluate salt tolerance at seedling stage. The results of membership function analysis showed that the salt tolerance of the five rice varieties from strong to weak was 'HH11'>'HD961'>'Nipponbare'>'9311'>'JX99'.

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.

Laticifer cells present in aging calli of Hevea brasiliensis. Methyl jasmonate (MeJA) and jasmonic acid (JA) belong to jasmonates (JAs). However, the effect of MeJA on laticifer cell differentiation of the rubber tree anther calli is unclear. In the present paper, the effect of MeJA on laticifer cell differentiation of anther calli was systematically studied. MeJA added to media in the range of 0-1 mg/L did not influence the growth of anther calli, while higher concentration of MeJA in media in the range of 2-3 mg/L severely inhibited callus growth. MeJA concentration in media was negatively correlated with callus growth. Histochemical sections showed that low concentration of MeJA in media greatly promoted the differentiation of callus laticifer cells and remarkably increased the occurring frequency, while high concentration of MeJA in media gravely impeded callus laticifer cell differentiation and strikingly decreased the occurring frequency. Among them, 1 mg/L MeJA in media was the optimal concentration to improve the differentiation of laticifer cells in calli. qPCR results showed that when the media were supplemented with MeJA, the change trend of the expression level of genes that was essential in latex biosynthesis, such as small rubber particle protein (SRPP), rubber elongation factor (REF), and cis-prenyl transferase (CPT), was basically consistent with that of the occurring frequency of callus laticifer cells, which further confirmed that MeJA promoted the differentiation of callus laticifer cells. Transmission electron microscopy observation showed that callus laticifer cells contained some specific organelles, such as rubber particles and lutoids. The results of this paper are of great significance for promoting the application of rubber tree callus in the study of laticifer differentiation, and for developing rubber tree novel yield-increasing reagents.

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.

Agave spp. is main resource of hard fiber. Zebra disease, caused by the pathogen Phytophthora nicotianae, is one of the most devastating sisal oomycete diseases. RXLR effector proteins are important cytoplasmic effectors of oomycete and more than 300 RXLR effector genes were identified in the genomes of P. nicotianae. RXLR effectors have the ability to manipulate or suppress host immunity by directly binding host proteins. A typical RXLR effector (named PnRXLR5863) that induced programmed cell death (PCD) was identified from P. nicotianae, but the targets in Agave were still unknown. This study aims to obtain the host plant proteins that are interacting with PnRXLR5863 in A. hybrid No.11648. A normalized cDNA library was constructed by combining Switching Mechanism at 5′ end of RNA Transcript (SMART) and Duplex-Specific Nuclease (DSN) technology. The capacity of cDNA library was 5.32×10⁷ CFU/ml, the independent clones was 1.064×10⁸ CFU, and the lengths of inserts ranged from 0.5 kb to 3.0 kb, with the recombination rate of 100%. A total of 23 proteins interacting with PnRXLR5863 were obtained by sequencing and homology analysis. Some of target proteins involve several physiological events, such as ubiquitination, protein synthesis, protein translation and protein translation, suggesting that PnRXLR5863 effector may act on protein metabolism of Agave spp. This research would lay a foundation for further study of the pathogenic mechanism of PnRXLR5863.

Macadamia nuts contain abundant source of unsaturated fat acid (UFA), but the molecular mechanism of biosynthesis of UFA remains to be further analyzed. Stearoyl acyl-carrier- protein desaturase catalyses the insertion of a double bond into saturated fatty acid bound in saturated acyl chains bound to ACP in higher plant, which is the key enzyme in unsaturated fatty acid biological synthesis pathway. The Macadamia intergrifolia plant as research object, the full-length gDNA and cDNA of SAD gene encoding stearoyl acyl-carrier- protein desaturase were isolated from M. integrifolia using PCR technique. The structure, function and expression pattern of MiSAD were preliminarily studied. The gDNA of SAD was 6947 bp and contained 3 exons and 2 introns. The open reading frame was 1191 bp and encoded 396 amino acids which was highly consistent with the public MtSAD sequence, and SAD was a water soluble enzyme with a total predicted molecular mass of 45.22 kDa and isoelectric point (pI) 5.93 located in chloroplast or plasmids stroma. The amino acid sequences of SAD involved in active site showed highly conserved and significant difference in N-end and C-end. The highly conserved region contained 2 central motifs of E-X-X-H iron atoms which formed the active site of this enzyme. The α-helix and random curl were predominate in the secondary structure. The helix-turning-helix was found in the prediction of tertiary structure for formation of fatty acyl chain binding site. Derived amino acid sequence showed the highest homology 94.2% with Telopea speciosissima, and the homology is above 80%in other species of SAD, close to Nelumbo nucifera in phylogentic tree. The SAD gene expression trends were basically identical by qRT-PCR. The SAD expression were found in root, stem, leaf, flower and macadamia nut, and the highest level was in nut. The expression of SAD gene increased about 90days after and reached the highest level at 100 days, then declined gradually in the following days during the macadamia nut maturation and presenting a normal distribution trend. This study would build a foundation for elucidating the molecular mechanism of MiSAD in biosynthesis of unsaturated fatty acid in macadamia.

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.