In this study, the effects of different concentration and ratio of growth regulators on seed germination, rapid propagation and in vitro flowering of Mengzia foliosa were studied. The results showed that the seeds had strong activity and high germination rate at 105 days after artificial self-pollination, and 1/2MS+0.6 mg/L NAA+1.0 mg/L 6-BA medium was more suitable for seed germination. Meanwhile, 2.0 mL/L 6-BA without NAA was more suitable for cluster bud proliferation; and 1/2MS+1.0 mL/L NAA+30 g/L potato homogenate medium was the best for rooting and hardening-off. In addition, 1.0 mg/L 6-BA+0.5 mg/L NAA+1.0 mg/L PP₃₃₃ medium had the highest flowering rate. Our results not only contribute to the conservation and sustainable use of the species, but also provide important materials and technical support for wild population restoration and reconstruction.

In the Orchidaceae family, Paphiopedilum exhibits extraordinary ornamental value and promising market prospects due to its unique appearance. However, Paphiopedilum is at risk of extinction worldwide due to slow growth rate, high environmental demands, and continuous collection by humans. Artificial seedlings can serve as a potential solution for ex situ conservation, reintroduction and commercial production. Unfortunately, artificial propagation is challenged due to low seed germination rate, slow growth rate, and limited resistance to ecological environments. Mycorrhizal symbiosis between plants and fungi has played a crucial role in the natural development of Paphiopedilum, particularly endophytic fungi, which significantly contribute to seed germination and plant growth. This article presents an analysis of features of endophytic fungi of Paphiopedilum, methods of endophytic fungi separation, types and functions of research, and the application prospects, while also outlining future research direction for the conservation of wild Paphiopedilum, seed germination and commercialization. This study aims to provide a comprehensive reference for future research on Paphiopedilum conservation, seed germination and commercialization.

Six nuclear extracts and three leaves of different development stage were screened to establish the flow cytometry (FCM) method for determining the genomic size of Piper L. and Cucumis sativus L. was used as the DNA reference standard. Result showed that the modified nuclear extract and inverted leaf were suitable for the flow cytometry of Piper L. The genome size of cultivated varieties, including Kuching, Aman and EMAS, ranged from 667.94 to 719.32 Mb, and Reyin1, microphylla variety from Cambodia, Panniyur-1 and 73F5 ranged from 759.69 to 785.38 Mb. Therefore, the genome size was significantly different among cultivated varieties. Furthermore, it is speculated that the chromosome numbers of P. wallichii and P. hancei, with genome size larger than 900 Mb, should be larger than 52 with a multiple of 13, and the number of chromosomes of germplasm, with genome size ranged from 600 to 800 Mb, may be 52. The hybrid not only had similar phenotypes to cultivated varieties and P. flaviflorum, but also had an average genome size of cultivated varieties and P. flaviflorum. Therefore, it is speculated that the hybrid may be the hybrid offspring of cultivated varieties and P. flaviflorum. This study would provide a method for the determination of the genome size of Piper L. germplasm, and provide a technical basis for the study of Piper L. germplasm evaluation and distant hybridization.

In order to understand the diversity and distribution characteristics of orchids in Gexigou National Nature Reserve in Sichuan province, a systematic survey was conducted using the line transect combined with sample sampling method from 2020 to 2021. A total length of 95 km including 17 lines were set up, covering various function, habitat and elevation of the reserve. 34 species of Orchidaceae in 20 genera were investigated. Among them, 10 were rare and endangered species, five were wild species under second-class national protection; and two (Liparis brunnea and L. rostrate) were new record species in Sichuan province. Most of them were mainly in terrestrial orchid of life type and absolutely dominant in north temperate zone of geographical. A total of 6703 orchids of 34 species were investigated and distributed in 290 sites. Galearis spathulata and Neottia megalochila were the most and least abundant species respectively, and Epipactis helleborine was the most widely-distributed. Among them, the height of Cypripedium guttatum showed a significant negative correlation with elevation, while there was a slightly correlation in other species. Most of Orchidaceae genera were distributed in 3100-3300 m, followed by 2900-3100 m, while the maximum number of individuals were distributed in 3900-4100 m. The number of Cephalanthera longifolia was positively correlated with slope significantly, the number of Galearis spathulata was positively correlated with elevation significantly, the number of Herminium lanceum was positively correlated with vegetation significantly, the number of whole genus of Herminium was positively correlated with elevation moderately. In general, the orchid resources in Gexigou Nature Reserve are relatively rich, and more distribute in the middle elevation. The number of some species is significantly correlated with environmental factors. Compared with the previous investigations in this reserve, the number of orchid species is significantly increased. However, three national protected species of Cypripedium with high ornamental value were not found, and the population of one species of Cypripedium decreased. Therefore, it is urgent to protect, publicize and enforce the law on orchids in the reserve.

Ploidy identification is one of the basic tasks for germplasm resources and new variety breeding of tropical flowers. In this study, flow cytometry was used to identify the ploidy level of Cymbidium hybrid seedlings. aiming at the key links such as the type of dissociated liquid, the tissue organ of the test material, evaluation indexes such as the nuclear dissociation, the clear degree of the main peak, the easy degree of sampling, and the coefficient of variation. A technique system was established and the stomatal traits of different ploidy were analyzed. The results showed that CyStain UV Precise P was the best of the three dissociated liquid and young leaves were most suitable. Six triploid and two tetraploid were identified from the offspring of the three hybrid combinations. There were significant differences in stomatal length, width and density between different ploidy (P<0.05). The rank of stomatal length and stomatal width was tetraploid>triploid>diploid, while stomatal density was reversed. This study is valuable for the polyploid selection and use of different ploidy germplasm resources for cross breeding of Cymbidium hybrid.

Phalaenopsis arunachalensis K. Gogoi & Rinya is reported as a little known species from Medog, Tibet Autonomous Region, China. The detailed morphological descriptions and photos are also provided. This species is similar to P. honghenensis F. Y. Liu, P. wilsonii Rolfe and P. taenialis (Lindl.) Christenson & Pradhan. However, this species has a minutely spurred that bends down, the free part of lateral lobes which are less than half length of the mid-lobe, and dagger-like of lateral lobes ends, which can distinguish from other species.

Phalaenopsis has a rich variety of flower colors, a long-lasting flowering period, a unique flower type, and high ornamental value. It is considered the most popular and commercially valuable orchid in the market. The axillary buds at the base of each leaf of Phalaenopsis orchid can form pedicels, but most of the axillary buds are in a dormant state during the flowering period. Studying the germination law of latent axillary buds can help improving the proportion of multiple flower stalks in Phalaenopsis, and has good application prospects. The main environmental factors (temperature, plant hormones, light environment, nutrient accumulation, etc) affecting the germination of Phalaenopsis bud and the regulatory methods to promote flower bud germination will be reviewed, in order to provide a reference for the application of regulating more flower bud germination in Phalaenopsis industry in the future.

Corynespora leaf fall disease is one of the most severe leaf diseases in major rubber planting countries worldwide, which can cause serious yield and economic losses. The selection, creation, and utilization of resistant germplasms are the most effective prevention and control strategies for this disease. This study evaluated the disease resistance of 821 F₁ populations from three hybrid combinations Yunyan 277-5×IAN 873, RRIC103×Reyan 8-79, Yunyan 277-5×Reken 525 and identified the level of disease resistance. Based on the evaluation results of disease resistance, 32 candidate F₁ generation individual plants were selected from two hybrid combinations that conform to normal distribution. Using three divergent clusters of Corynespora cassiicola and two evaluation methods to identify the resistant candidate F₁ clone seedlings, five resistant germplasms were ultimately obtained by measuring the activity of defense enzymes and analyzing the expression characteristics of disease-related genes in five new resistant germplasms. Further investigation confirmed that the interaction relationship between five new resistant germplasms and multi host C. cassiicola during the infection process. This study provides excellent germplasm materials and a theoretical support for the early selection, cultivation, and utilization of resistant germplasms for the disease resistance of Corynespora leaf fall disease.

Eight germplasm resources of Camellia sect. Chrysantha from Daweishan Mountain of Yunnan province were studied to provide scientific basis and research materials for the exploitation and utilization of Camellia plants. In this study, the leaf length and width of 13 cultivars of Camellia sect. Chrysantha were evaluated by direct observation of leaf phenotype, using five known germplasm resources as the control and mature leaves as the test materials, the content of six mineral elements (Cu, Zn, Fe, Mn, Ca, Mg) was determined by the wet ashing method, the contents of four functional components (tea polyphenols, total polysaccharides, total saponins and total flavonoids) were determined by the UV photometer method, the relationship between them and germplasm resources of Camellia sect. Chrysantha was analyzed by the cluster analysis. The results showed that the leaf shape of 13 Camellia sect. Chrysantha could be divided into two types: elliptic and oblong, and there were great differences in leaf area, leaf color and leaf serration. The highest and lowest content of Cu, Zn, Fe, Mn, Ca and Mg in leaves was 2.1, 1.9, 4.3, 6.6, 1.4 and 1.8 times, respectively. The content of total saponins, tea polyphenols, polysaccharides and flavonoids was 10.9, 5.8, 5.0 and 2.0 times, respectively. The correlation analysis showed that tea polyphenols had a significant negative correlation with leaf length/leaf width, a significant positive correlation with leaf color and leaf quality, and a significant negative correlation with leaf length/leaf width and zinc, there were significant positive correlations between leaf color and manganese, villi and copper. The results of cluster analysis showed that the 13 germplasm resources could be divided into 5 groups when the distance coefficient was 4.5, group I (including ‘Honghe 1’ Camellia sect. Chrysantha, JHC-2, JHC-3, JHC-4) and Group IV (including ordinary Camellia sect. Chrysantha, JHC-8, Camellia pubipetala Wan et Huang) contained relatively high contents of the constituents, JHC-2 and JHC-8 may have higher medicinal and health-care functions, but the mineral element contents and contents were generally higher, so the later development and utilization value was higher. The results of this study would be useful for further studies on the accumulation mechanism of important functional components in Camellia sect. Chrysantha, it would also provide theoretical basis for breeding new varieties of Camellia and further development and utilization of Camellia group plants in the future.

Ca²⁺ is a second messenger in plant cells, and Ca²⁺-ATPase (ACA/ECA), as an important protein in Ca²+transport, plays a crucial role in ensuring the balance of intracellular calcium ions and abiotic stress in plants. To investigate the biological function of Ca²⁺-ATPase (ACA/ECA) in Hevea brasiliensis, 45 ACA/ECA gene family members were identified from the rubber tree genome using the ACA/ECA protein sequence of the model plant Arabidopsis as a probe, including 38 ACA members and 7 ECA members. Expasy and Plant-mPLoc were used to comprehensively analyze the physicochemical properties, gene structure, chromosomal localization, phylogeny, and expression patterns of the 45 members. Physicochemical properties analysis showed that the number of amino acids encoded by each member was 86-1142, the molecular weight of amino acids ranged from 10 048.04 to 125 412.75 Da, and the protein products were mostly localized on the cytoplasmic membrane, with a few members localized on the endoplasmic reticulum, chloroplast, vacuole, and nucleus. In evolutionary, members of the ACA/ECA family were clearly clustered into ACA and ECA two branches, and rubber tree members were always in close proximity to cassava in both branches, indicating that there was a close relative between rubber tree and cassava during phylogeny. Chromosomal localization revealed that the 45 members of the ACA/ECA family were unevenly distributed across 14 chromosomes and one contig in rubber tree, in which, chromosomes 2 and 9 had the largest member distribution of 11 members. Expression analysis showed that there were obvious differences in the expression of some members in different groups, HbACA31 was expressed the most in leaves, HbACA36 was expressed the most in latex, and the expression of HbACA36 was obviously up-regulated in latex after treatment with ethenol. In addition, we also analyzed the influence of tapping on ACA/ECA gene expression, and found that HbACA36 was at a high expression level during tapping of the two rubber tree varieties, PR107 and Reyan 8-79, and significantly up-regulated during tapping of high-yield variety Reyan 8-79, which speculated that HbACA36 was involved in the regulation of rubber biosynthesis and played an important role. The results presented in this study reveal the physicochemical properties and expression patterns of ACA/CA family members for the first time in rubber tree, and would provide a foundation for further investigation of the biological functions of ACA/ECA genes in H. brasiliensis, especially in the regulation of the rubber production.