Curcuma alsimatifolia is a perennial bulbous herb of the genus Curcuma in the Gingeraceae.family The inflorescence of C. alismatifolia resembles tulips and enjoys the reputation of “tropical tulips”. C. alsimatifolia was introduced into China from Thailand and it is acclaimed by an ever-increasing number of consumers. The varieties of C. alismatifolia are relying on import in China today. The lack of new varieties with proprietary intellectual property rights limits the development of C. alismatifolia industry in China. Three different cross combinations of 327 hybrid offspring were constructed using the Siam TM Sitrone variety of C. alismatifolia as the female parent to breed new varieties of C. alismatifolia with independent intellectual property rights and increase the variety diversity. Eleven pairs of SSR primers were selected to analyze the hybrid F₁ generation of the three cross combinations and the parents, and five pairs of specific SSR primers were selected for each cross combination to identify the authenticity of the hybrid F₁ generation. The genetic segregation pattern and genetic diversity and genetic relationship of the parental and hybrid F₁ generation populations were also analyzed. The results showed that the eleven pairs of SSR markers had high resolution and good amplification polymorphism for the three parental materials, and each parent had its specific SSR markers, which could effectively identify the genetic authenticity of the hybrid offspring. True hybridization rates of 91.8%, 90.8% and 93.4% were identified in 327 F₁ individuals The SSR molecular marker primers had high polymorphism and could be directly used for C. alismatifolia genetic diversity analysis, hybrid identification and other related studies, providing efficient and reliable SSR marker selection for future identification of hybrid progeny, while the identified true C. alismatifolia progeny population could provide germplasm for genetic studies of superior traits. The identification of authentic C. alismatifolia progeny could provide germplasm materials for genetic research on superior traits and provide scientific basis for the selection of new varieties.

A nitrogen fixing bacteria strain named BWLY3X-6 was isolated from the rhizosphere soil of wild banana (Musa nana Lour. sp) in Hainan, China using Ashby nitrogen free medium, and .its morphological characteristics, physiological and biochemical characteristics, 16S rRNA and gyrB sequence analysis, nitrogen fixation characteristics and growth promoting ability to different banana varieties were studied. The strain was identified as an azotobacter Klebsiella variicola, and its extracellular ammonia nitrogen content was (17.98±1.88)μg/mL, nitrogenase activity was (220.51±8.21) ng/L. The results of the growth promoting test of the strain on different banana varieties showed that, compared with the blank control and 0.5% urea treatment, after inoculation with BWLY3X-6, under the inoculation concentration of 10⁶ CFU/mL and 10⁸ CFU/mL, there were significant changes in various biomass of M. acuminata AAA Cavendish cv. Nantianhuang and M. acuminata AAA Cavendish cv. Baxi (P<0.05), with more significant changes in root length, with the increase ratio of 43.5% and 54.6% respectively. In this study, nitrogen fixing bacteria with good nitrogen fixing ability were screened, and this strain had a good promoting effect on banana growth, wihich would provide a theoretical basis for its subsequent practical application in agricultural production.

Gypsophila paniculata L. is one of the most popular and bestselling cut flowers in the world. Stem rot is among the common disease of G. paniculata L. causing plant withering and death in serious cases, affecting the ornamental and utilization value of the flowers and causing certain economic losses. In March 2021, a severe wilt due to stem rot was observed on G. paniculata L. in Haikou town, Kunming, Yunnan, China. The disease mainly affected the stem base which was manifested by rot on stem base and wilting. In order to identify the pathogenic microorganism, we isolated and identified the pathogen associated with the stem of G. paniculata L.. Koch’s postulates proved that the isolate caused similar symptom on tissue culture and potted seedlings of G. paniculata L., and the isolate had similar morphology with initially isolated from with the naturally infected seedlings in the field. Through morphological identification, the isolate produced a large number of dense aerial hyphae with color ranging from white to light orange or yellow with dark red pigment deposition on the back of the colony. The conidia of the isolate was sickle-shaped with flat ventral side, the dorsal side was arched, with three to six septation. The macroconidia was in the range (21.1-57.9)µm×(2.7-5.1)µm (n=100), no microconidia were observed. The morphology was similar to that of Fusarium pathogenic fungi. Through the identification of ITS gene sequence and morphology, the isolate was initially identified as F. graminearum species complex (FGSC). In order to further identify the subspecies, the TEF-1α sequence was used for sequencing. It was found that the isolate was 100% homologous with F. meridionale. Therefore, combined with morphological and molecular biological characteristics, the pathogen of the stem rot of G. paniculata L. was identified as F. meridionale. This is the first report on the stem rot of G. paniculata L. in China, which would provide an important basis for the prevention and control of the disease.

Phosphorus (P) is an essential macro-element for crop growth and is involved in critical physiological and biochemical processes in plants. Pitaya is an important economic crop in tropical and subtropical regions. High fruit P concentration and huge yield require high P demand for pitaya growth. However, the P absorption characteristics of pitaya and the relationship of root morpho-physiological processes and P uptake are still unclear. In this study, pitaya variety Soft Dahong, which is the most popular cultivar in China, was used. Five P gradients of 0, 0.01, 0.1, 0.5 and 1.0 mmol/L were set by hydroponic experiment to explore the changes of root morphology and physiological process of pitaya under different P application rates. At the same time, the content of phosphorus and other nutrient elements in the aboveground part were analyzed to clarify the mechanism of root morphological and physiological traits for efficient P use and the effect of P supply on other nutrients uptake in pitaya. The results showed that compared with no P, P fertilizer application did not affect the accumulation of aboveground biomass. P uptake and P concentration of shoot increased with the P application rates. The total root length and the number of fine roots with diameter≤0.05 mm in low P treatment (0.1 mmol/L) were significantly higher than those of other treatments. High P supply inhibited root growth, showing that the total root length was the shortest, and the number of coarse roots with diameter≥2 mm was higher than that of other treatments. Low P (0.01 mmol/L) treatment had the highest total organic acid content and higher root CEC content. Compared with no P, the organic acid secretion rate and root CEC content decreased under high P supply (1.0 mmol/L). In terms of the absorption of other nutrient elements, the absorption concentration of iron in the mother branch and the primary branch decreased gradually with the increase of P rate. The contents of nitrogen, calcium, magnesium, manganese and zinc in the second order branches decreased gradually with the increase of P rate, showing a significant negative correlation. This study showed that low P and moderate P supply (0.01 mmol/L or 0.1 mmol/L) could promote root growth, root organic acid secretion and ion absorption capacity of pitaya, while excessive P supply (1.0 mmol/L) significantly inhibited root growth and significantly reduced the absorption of trace elements accumulation in shoots. Therefore, rational application of P fertilizer is of great significance for pitaya to maximize its root biological potential and improve the P use efficiency, and also plays a key role in the balance of trace elements uptake in plants.

Anthracnose is a common disease of coffee, which causes serious loss to the yield and quality of coffee fruit. The research on pathogenicity and biological characteristics of the pathogenic bacteria causing coffee anthracnose and screening of effective antagonists would provide reference for the biological control of coffee anthracnose. Four coffee anthracnose pathogens Wyq1 (Colletotrichum siamense), Yyq1 (C. fructicola), Xbd1 (C. gloeosporioides) and Hb1 (C. theobromicola) were isolated and tested for pathogenicity by spore suspension, and the most virulent strains were selected for further experiments. The biological characteristics of the pathogenic bacteria were studied by the plate culture method. Screening of antagonistic bacteria was done by the plate confrontation method. Xbd1 strain could infect healthy coffee leaves, and its virulence was the strongest among the four strains. The most suitable medium for the vegetative growth was PDA. The optimal nitrogen source was tryptone. The most suitable carbon source was glucose. The optimum temperature was 28 ℃. The optimal pH was 7. The difference of vegetative growth was not significant under different light conditions. Bacillus subtilis MC4-2, B. tequilensis D5-8, B. velezensis MC2-1 and B. flexus ZLSY3 and B. amyloliticus GJ7 showed good antagonistic effect in indoor screening. B. subtilis MC4-2 had the best antagonistic effect, with an inhibitory rate of 57.8%. The study would lay the foundation for the control of anthrax and the development of biocontrol agents.

Pterocarpus santalinus is one of the most famous rosewood (Hongmu) species in the world. Its large-scale development is restricted due to limited seed production in China. A grafted clone seed orchard was established recently using suprior tree materials by Experiment Station of Research Institute of Tropical Forestry, Chinese Academy of Forestry in Jianfengling, Hainan Island, and most trees in the orchard have flowered and fruited. The differences in seed quality among superior trees in the introduction garden and the grafted clones need to be studied. Here the morphological traits were measured, and germination tests were conducted for the seeds of P. santalinus collected from six superior trees in the introduction garden and the grafted clones in the seed orchard at the experiment station. The coefficients of variance for the seed morphological traits were much lower than those for seedling growth traits among superior trees or the grafted clones, and the coefficients of variance was the lowest for the weight of 1000-grain seeds, indicating that the variations of seedling growth were more abundant than those of seed morphorlogy Seed length was significantly different at 0.05 level among the superior trees with No. 7 performing the best, and seed length, width and thickness differed remarkably among the grafted clones, in which No. 9^# performed the best in seed length and width, and No. 7^# did the best in seed thickness. The germination rate and potential differed significantly among superior trees (No. 3 and No. 9 performed the best, respectively) or the clones (No. 5^# did the best), and significant difference occurred in the length of epicotyl, hypocotyl, radicle and total seedling among the superior trees (No. 3 did the best), and in the length of radicle and total seedling among the grafted clones (No. 7^# did the best), demonstrating that abundant variation in seed germination and seedling growth existed among superior trees and among the grafted clones. Significance of difference between each superior tree and its clone varied with gene type, and clones performed as a whole, better than relevant superior trees in seed length and width, seed germination and seedling growth. It was indicated from relationship analysis that seed weight was significantly correlated with germination rate at 0.01 level, the germination rate of the plumper seeds was higher. In conclusion, seeds from the grafted clone seed orchard performed better in the seed morphorlogy and germination than those from the superior trees in the introduction garden, and significant difference was absent in seed weight among the superior trees or the grafted clones, and between each superior tree and its clone (P≥0.05), the seeds developed fully in the seed orchard with 1000-grain weight near 100 g, more than that for scattered individuals early grafted (92.9 g). The findings would provide scientific evidences for elite variety selection, seed orchard establishment and robust seedling cultivation.

Amomum tsao-ko (AT) is a medicinal and food homologous crop rich in polyphenols and flavonoids. The germplasm of AT is relatively mixed, and it is urgent to carry out research on AT germplasm resources and screening of high-quality AT seed sources. This study aimed to screen and evaluate the content of polyphenols and flavonoids and antioxidant activities of laxative active components of AT resources, and to explore the possible factors of component accumulation. In this study, a total of 57 samples were collected in Laos, Myanmar, Sichuan, Guangxi and Yunnan in China, and the polyphenol content and flavonoid content of AT aqueous extract were determined by forinphenol method and NaNO₂-Al (NO₃)₃-NaOH colorimetric method, and the DPPH radical scavenging ability of AT aqueous extract was detected. The correlation between polyphenol and flavonoid content, DPPH radical scavenging capacity and geographic factors was analyzed. The results showed that the content of polyphenols and flavonoids in spindle-shaped AT resources was higher than that of oval fruit and round fruit, and the content of flavonoids in AT resources abroad and Nujiang was higher than that in other regions (outside the province, western Yunnan, southwest Yunnan, Wenshan and Honghe). The content of AT polyphenols and flavonoids was significantly positively correlated with DPPH radical scavenging capacity and altitude (P<0.05), and negatively correlated with longitude (P<0.05) and latitude (P>0.05), so it was speculated that the accumulation of AT polyphenols and flavonoids may be related to temperature, light, ultraviolet rays and soil moisture. Finally, according to polyphenols, flavonoids, the classification standards were formulated, and the AT resources were divided into three grades, which would provide an analysis method for the establishment of the AT quality grade evaluation system. The excellent AT resources were screened by this method as Nujiang samples GS-3 and GS-10 and foreign samples MDL-1 and MGK-2. This study would provide a scientific basis for the investigation and collection of AT, as well as the study of origin and evolution, and also lay a solid foundation for the utilization of AT resources and the development of industry in the future.

Cordyceps chanhua is an important Chinese traditional medicine and food, that has important application value in the development of green functional food and new resource drugs. Taking one wild fungi Chanhua collected from Qujing of Yunnan province as the experimental material, the biological characteristics and artificial cultivation conditions were studied for the purpose of domestication and cultivation. Based on the morphological anatomy and molecular phylogenetic analysis, a wild ascomycetes was identified as C. chanhua. The biological characteristics and domestication of C. chanhua strain were studied by single factor experiments and orthogonal tests. The result showed that the branch stalk of C. chanhua was orange yellow or yellow white, (8.0-28.0) mm×(1.5-3.0) mm, and the conidia was oblong, (4.0-8.5)µm×(1.5-3.5)µm. The optimum temperature for the mycelial growth was 24 ℃, the optimum pH value was 6, the carbon source, nitrogen source and mineral salt was sucrose, yeast powder and magnesium sulfate respectively. The results of orthogonal test based on three factors under the optimum pH value and temperature showed that carbon source had the greatest impact on the mycelial growth, followed by nitrogen source and mineral salt, with range 1.21, 0.39 and 0.13 respectively. Therefore, the optimal combination of factors for the mycelial growth of C. chanhua was sucrose 20 g/L, yeast powder 2 g/L and magnesium sulfate 2 g/L. The artificial cultivation of C. chanhua utilized the 1∶1 mixed medium of wheat and rice, and the harvest cycle of fruiting body was about 40-45 days, and the average dry weight of each cultivated Chanhua was about 9.56 g. The external morphological characteristics of artificially harvested C. chanhua were significantly different from those of wild fruiting body. The fruiting body was yellowish to light yellow, with few branches, 1.5-5.0 cm in length, 0.3-0.8 cm in width and 0.1-0.2 cm in depth. The sporangium bundles were covered with dirty white flocculent or powdery conidia. The screening of excellent strains and optimal culture conditions of C. chanhua would provide a theoretical basis for its study on the diversity of germplasm resources, protection and utilization.

The effect of composite passivators on the in-situ Cd contaminated soil and its absorption and accumulation of Cd in cabbage were explored, which would provide a scientific basis for the treatment and restoration of medium and mild Cd contaminated farmland. Field experiments were carried out in Cd polluted farmland soil with five passivator combinations: red mud + lime + phosphate rock powder (T₁), red mud + lime + biochar (T₂), lime + humic acid + sepiolite (T₃), sepiolite + biochar + red mud (T₄), sepiolite + biochar + phosphate rock powder (T₅), in order to study the effects of the five passivating agent combinations on the content of various forms of Cd, enzyme activity, microbial carbon (MBC), microbial nitrogen (MBN) and the absorption and accumulation of Cd in various parts of Chinese cabbage in the cultivated layered soil. The five compound passivating agents could improve soil pH and reduce the availability of Cd in the soil in different degrees. Soil pH in T₃, T₄ and T₅ treatments was significantly higher than that in CK, and soil available Cd content in T₂, T₃, T₄ and T₅ treatments was significantly lower than that in CK. In each form of Cd, in T₅ treatment, the content of Cd in weak acid extraction state and reducible state was significantly higher than that in CK, while the content of Cd in residue state was significantly lower than that in CK. Compared with CK, T₁, T₃, T₄ and T₅ treatments significantly increased soil sucrase and acid phosphatase activities by 42.06%-152.46% and 15.95%-26.48%, respectively. Treatments T₁, T₂, T₃ and T₄ significantly increased urease activity by 18.43%-35.19%, treatments T₃ and T₄ significantly increased catalase activity by 18.78%-19.01%, treatments T₁, T₂ and T₃ significantly increased soil MBC content by 31.83%-53.19%. T₂, T₃ and T₄ treatments significantly increased soil MBN content by 19.14%-59.89%. Different treatments had different effects on Cd absorption and accumulation in different parts of Chinese cabbage. Compared with CK, T₄ and T₅ treatments significantly reduced Cd content in roots, T₁, T₄ and T₅ treatments significantly reduced Cd content in stems, and the five treatments significantly reduced Cd content in leaves, and the enrichment and transport capacity of Cd in leaves of Chinese cabbage was greater than that in stems and roots. In terms of comprehensive passivation effect, T₄ and T₅ treatments, namely sepiolite + biochar + red mud (3∶5∶3), sepiolite + biochar + phosphate powder (3∶5∶3), had better passivation effect in the field soil mildly polluted by Cd during in-situ passivation restoration, which could effectively reduce the absorption of heavy metal Cd in soil by plants.

Rhododendron hainanense Merr. has high ornamental and ecological value. It is of great significance for the protection and application of this plant through the study of ecological requirement and applicable range. In this paper, MaxEnt model and ArcGIS were used to simulate the potential geographical distribution of R. hainanense in China, based on the existing geographic distribution information, climate factors of this plant. And the key environmental factors, affecting the potential distribution of R. hainanense and suitable thresholds are analyzed. The results showed that under the contemporary climate scenario (1970—2000), the maximum entropy model (MaxEnt) can predict the suitable area of R. hainanense with high accuracy. The temperature and precipitation have a great influence on R. hainanense. The main factors affecting the potential distribution of R. hainanense are precipitation of warmest quarter (bio18) and mean diurnal range (bio2). When the precipitation of warmest quarter (bio18) is between 610-3990 mm and the mean diurnal range (bio2) is 5-7 ℃, the climate environment is suitable for the growth of R. hainanense. In a certain range, the probability of presence of R. hainanense will increase with the increase of precipitation. In China, the suitable habitat area of R. hainanense is mainly distributed in Hainan, Guangxi, Guangdong, Taiwan, eastern Sichuan, Chongqing and Guizhou. The total suitable habitat area of R. hainanense under contemporary climate scenarios is 132.36×10⁴ km². The purpose of this paper is to provide a scientific basis for the protection and application for the species.