We have discovered and reported a litchi male sterile line MS1 recently but the characteristics of this male sterile was still unclear. In this study, grafted litchi male sterile line MS1 was used as the experimental materials and all the materials were planted in plastic pots. Anther fertility of the litchi male-sterile line MS1, characterized by off-season flowering, was assessed via morphological observation and paraffin sectioning. The results demonstrated that MS1 produced a low proportion of male flowers during high-temperature seasons. Moreover, both male and female flowers lacked viable pollen grains yet exhibited parthenocarpic ability. This study confirmed the stable male sterility of the MS1 line under high-temperature conditions, which lays the groundwork for determining its sterility type, and provides preliminary strategies for achieving off-season flowering in litchi.

Germplasm resources are the key material support for the breeding of new mango varieties and the sustainable development of the industry, and the efficient conservation and utilization are of great significance for mango research. In the study, 431 mango germplasm accessions were used. Combining different sampling strategies and genetic distances, the optimal sampling strategy combination for constructing the mango core collection was screened by the UPGMA clustering method, and the core collection was subsequently established. The results showed that the average effective number of alleles (Ne), average Shannon's information index (I), and average Nei's diversity index (H) of 12 pairs of primers was 4.0993, 1.534 and 0.7361, respectively, indicating that the mango germplasm possessed rich genetic diversity. The t-test results of genetic diversity parameters revealed that the core collection constructed by the combination of the locus priority sampling strategy and Nei & Li genetic distance had the highest Ne, H and I among all tested groups, with value of 4.2603, 0.7486 and 1.5855, respectively, demonstrating that the combination was the optimal method for constructing the mango core collection. The established core collection comprised 85 accessions, accounting for 19.72% of the original germplasm. The retention rate of Ne, I and H in the core collection reached 103.93%, 103.35% and 101.45%, respectively, indicating that although the core collection was much smaller in quantity than the original germplasm, it exhibited superior performance in genetic diversity-related indicators. Principal coordinate analysis (PCoA) showed that the distribution of the core collection uniformly covered the distribution range of the original germplasm in the principal coordinate space, suggesting that the core collection could comprehensively retain the genetic diversity characteristics of the original germplasm and had good representativeness.

Elucidating the response of rhizosphere soil microorganisms to the invasion of Fusarium in pepper provides a theoretical foundation and technical support for research on pepper rhizosphere microecology, the exploration of superior biocontrol resources, and the targeted control of pepper Fusarium wilt. Rhizosphere soil samples were collected from healthy (CK), mildly diseased (T₁), moderately diseased (T₂) and severely diseased (T₃) pepper plants. High-throughput sequencing and bioinformatics analyses were employed to compare the community structure and diversity of rhizosphere microorganisms and to assess the functional differences. CK had the highest number of unique bacterial OTUs, while T₁ had the highest number of unique fungal OTUs. At the genus level, the dominant bacterial genera included unclassified Acidobacteriaceae、unclassified Bacteria、unclassified Rhodospirillales、Gaiella、unclassified Betaproteobacteria、Terrimonas、unclassified Desulfuromonadia and Fontisphaera the dominant fungal genera included Thermoascus, Mortierella, Apiotrichum, Fusarium, Rasamsonia, unclassified Fungi, Paracremonium, Talaromyces, Debaryomyces and Metarhizium. With increasing disease severity, the richness of both bacteria and fungi initially increased and then decreased, while the diversity showed a trend of initial increase, followed by a decrease, and then a subsequent increase. PCoA results revealed distinct differences in bacterial and fungal communities among the treatments. Linear discriminant analysis (LEfSe) identified 14, 2, 6 and 6 bacteria-specific species at the genus level, respectively, and 12, 10, 7 and 9 fungi-specific species for CK, T₁, T₂ and T₃, respectively. Cross-domain correlation analysis between rhizosphere bacteria and fungi demonstrated that Fusarium was negatively correlated with Acidibacter, Bradyrhizobium and Bryobacter. As disease severity increased, the network parameters of bacterial and fungal community interactions exhibited an initial rise, followed by a decline, and then a subsequent rise. The abundance of potentially pathogenic microorganisms was significantly higher in diseased plants than that in healthy peppers, while the abundance of stress-tolerant microorganisms initially increased significantly and then decreased. The relative abundance of saprotrophs was significantly higher in severely diseased plants compared to healthy peppers, and the abundance of plant pathogens showed a significant increase-decrease-increase trend. Pepper Fusarium wilt significantly altered the characteristics of the rhizosphere soil microbiome. In the early stages of disease, pepper roots likely resist Fusarium infection by recruiting beneficial microorganisms, stimulating bacterial stress tolerance, and enhancing fungal saprotrophic and symbiotic functions. In the middle and late stages, intensified root damage leads to a decline in recruitment capacity, allowing pathogens to dominate and beneficial microbial communities to be suppressed.

Konjac (Amorphophallus spp.) is an important medicine and food economic crop in China, but its industrial development has long been threatened by soft rot disease, known as the konjac 'cancer'. Hainan is an emerging konjac producing area, but the current epidemiological pattern of konjac soft rot disease and pathogenic bacteria population structure is not clarified. The study was aimed to carry out soft rot disease investigation, pathogen isolation and identification, and to provide a scientific basis for the control of the disease. The survey of konjac soft rot disease in six cities and counties in Hainan showed that the highest incidence rate (46.01%) was found in the third team of Danzhou Experimental Farm, while that of Wenchang planting base is low (8.25%). Combining morphology, molecular biology (16S rDNA, proA, gapA and mdh multigene phylogenetic analysis) identifications and distribution information of pathogens, Dickeya fangzhongdai (88.64% of the total), Pectobacterium aroidearum (6.82%) and P. colocasium (4.54%), were the cause of the disease. Pathogenicity assay showed that D. fangzhongdai was high pathogenicity, and indoor screening showed that 0.3% tetramycin had the best inhibitory effect on D. fangzhongdai, with the lowest inhibitory concentration (MIC) of 1.825 μg/mL, followed by 80% ethacrynicin (MIC of 25 μg/mL) and 25% bromoxynil (MIC of 125 μg/mL). The dynamic changes of defence antioxidant enzymes and malondialdehyde in konjac in response to D. fangzhongdai infestation were determined by pot inoculation experiment. The results showed that the activity of superoxide dismutase (SOD) and peroxidase (POD) reached 182.57 U/g and 300.33 U/g, respectively, after 72 h of infestation, which was 2.27-fold and 7.03-fold higher than that of the control, while the activity of catalase (CAT) peaked at 24 h (1093.67 U/g) and decreased to 658.01 U/g in the later period (72 h). Malondialdehyde (MDA) content increased incrementally with infestation time and increased by 30.51% at 72 h compared to the control, and β-galactosidase (β-GAL) activity continued to rise [97 nmol/(min·g)] and increased by 36.86% compared to the control.

High yield with cold resistance clones is the core objective of rubber tree breeding in Yunnan. In this study, the cold-resistant clone GT1, which exhibits strong tolerance to radiative chilling injury, was selected as the female parent, and the widely cultivated fast-growing, high-yielding variety Yunyan 277-5 was used as the male parent. Through artificial isolated pollination, hybrid offspring were obtained. After a sexual family trial, individual plants with potentials were selected from the progeny population and entered into small-scale and large-scale clone comparative trials. This process led to the selection of an excellent clone, Yunyan 76-235, which is characterized by high yield and fast growth with the cold resistance and latex production type comparable to the clone RRIM600. Thirty years of systematic evaluation demonstrated that Yunyan 76-235 exhibits rapid early growth, with an average annual girth increment of 6.0 cm by the 6^th year after planting in the primary trial area, which is 115.4% of the clone RRIM600. It also shows high yield of dry rubber, with an average annual dry rubber yield per tree of 2.64 kg in years 1-5 of tapping in the small-scale clone comparative trials, representing 149.26% and 168.54% of the RRIM600 and GT1, respectively. In the large-scale clone comparative trials, the average annual rubber production per tree in years 1-13 of tapping was 4.6 kg, which is 140.12% of the RRIM600. Its cold resistance is stronger than that of RRIM600 but weaker than that of GT1 and Yunyan 77-4. The successful breeding of clone Yunyan 76-235 enriches the genetic resources for rubber cultivation in areas of Yunnan where prone to mild and moderate cold damage, providing variety support for the development and enhancement of the local rubber industry.

The aim of the study was to characterize the chloroplast genome structure and phylogenetic relationships within the genus Bulbophyllum. We sequenced, assembled, and annotated the chloroplast genomes of B. rothschildianum and B. longissimum for the first time. Comparative analyses of codon usage bias, repeat sequences, and sequence variation were then conducted with the available chloroplast genomes from four previously published Bulbophyllum species. The chloroplast genome of B. rothschildianum and B. longissimum was 148 447 bp and 151 095 bp, respectively, both showing a typical circular quadripartite structure containing 126 and 129 functional genes. Codons encoding leucine exhibited the strongest usage bias, with codons ending in A/U being particularly abundant. SSR analysis revealed mononucleotide repeats (predominantly A/T type) were most abundant, and palindromic repeats dominated among long repeats. Highly variable regions were mainly located in non-coding regions and selected coding genes (e.g., matK and ycf1), with evident expansion and contraction at IR/SC boundaries. Phylogenetic analysis showed that the 32 Bulbophyllum species formed a strongly supported clade and exhibited clear geographic differentiation into Asian and Central and South American lineages, with B. rothschildianum and B. longissimum clustering together within the Asian lineage and being closely related. The study would provide molecular insights into resource development, genetic conservation, and systematic research in the genus Bulbophyllum.

Plant annexin is a conserved calcium-dependent phospholipid binding protein involved in plant growth, development and stress resistance. The sequence characteristics and expression patterns of the ANX gene family in C. oleifera remain unclear. For this reason, the present study aims to investigate the expression regulatory mechanisms of this gene family in the stress resistance responses of C. oleifera. Three ANX genes were identified from the whole genome of C. oleifera, and the physical and chemical characteristics, evolutionary relationship, gene structure, conserved sequence, chromosome location, expression level in different tissues and the content of annexin under drought stress were analyzed in the study. Phylogenetic analysis showed that 15 different families were clustered into 5 groups, among which CsANX and CoANX1/2 from Camellia were clustered into a large branch with similar motif patterns. Many cis-elements involved in light response and plant hormone response were identified in the promoter region of CoANX. Chromosome localization showed that the three CoANX genes were distributed on three chromosomes (A_chr 09/13/14) of C. oleifera. The expression pattern analysis showed that CoANX showed tissue-specific patterns in different growth stages and tissues. In addition, stress analysis showed that CoANX3 showed a high expression trend under drought conditions, while the expression of CoANX3 in the treatment group sprayed with brassinolide decreased. Under phosphorus and aluminum stress, the expression of ANX in C. oleifera increased significantly. The above results indicate that CoANX may play a key role in the stress resistance of C. oleifera. This study would lay a foundation for elucidating the molecular mechanism of ANXs in regulating the biological processes of plant growth and development.

Ten melon germplasm accessions were treated under simulated low-temperature and weak-light conditions in this study to establish an efficient identification system for low-temperature and weak-light tolerance of melon (Cucumis melo L.) germplasm at the seedling stage. The relative changes in 8 growth indicators (including plant height, stem diameter, leaf area, etc.) and 10 physiological indicators (including chlorophyll content, root activity, relative electrical conductivity, etc.) were determined, and the damage indexs were calculated to initially evaluate the low-temperature and weak-light tolerance of each germplasm. Based on the membership function method in fuzzy mathematics, 19 identification indicators were standardized. Dimensionality reduction was performed via principal component analysis (PCA), and 5 principal components with strong correlations to the low-temperature and weak-light tolerance index, peroxidase (POD) activity, root length, root activity, and soluble protein content were extracted (cumulative contribution rate: 87.026%). Cluster analysis was conducted on the 10 melon germplasm accessions, which were classified into three groups. Group Ⅰ including Vedrantais and M18, was classified as strong low-temperature and weak-light tolerant. Group Ⅱ includding IranH, Topmark, M4 and Nantais oblong, was classified as moderate low-temperature and weak-light tolerant. Group Ⅲ including PI124111, MR1, M76 and PMR5, was classified as weak low-temperature and weak-light tolerant. Finally, stepwise linear regression was used to establish a prediction model for low-temperature and weak-light tolerance of melon at the seedling stage, D=-0.058+0.008X₁₅+0.442X₉+0.058X₁-0.017X₁₉ (R²=0.998, P<0.001), X₁₅ is proline content; X₉ is root length; X₁ is low temperature and low light tolerance index; X₁₉ is peroxidase activity. To verify the reliability of the above identification results, the expression patterns of CmADF1 and CmCYP195 (key genes responding to low-temperature and weak-light stress) were analyzed in germplasm accessions M4, PI124111 and PMR5 at different time points after low-temperature and weak-light treatment. The results showed that the expression characteristics of CmADF1 and CmCYP195 were consistent with the identified low-temperature and weak-light tolerance types of the germplasm, which further confirmed the reliability of the identification system. The results could serve as identification criteria for evaluating low-temperature and weak-light tolerance of different melon germplasm accessions and provide breeding materials for subsequent improvement of melon varieties with low-temperature and weak-light tolerance.

The study was aimed to solve the problems of relatively extensive cultivation and low soil quality of Pandanus amaryllifolius that restrict the improvement of yield and quality. Different ratios of biochar combined with mushroom residue were used to improve the soil, clarify its yield-increasing effect and mechanism, and to provide technical support for efficient cultivation of Pandanus. Under basic fertilization, four treatments were set up, 800 kg/hm² mushroom residue (MD), 800 kg/hm² mushroom residue + 1600 kg/hm² biochar (MDB1), 800 kg/hm² mushroom residue +3200 kg/hm² biochar (MDB2), and no mushroom residue or biochar added (CK). A field plot experiment was conducted to study the effects of different treatments on plant growth and yield, soil physicochemical properties and microbial community structure of Pandanus. Compared with CK, the yield increase effect of mushroom residue alone (MD) did not reach a significant level, while the biochar combined application treatments (MDB1, MDB2) significantly increased the fresh leaf yield of P. amaryllifolius. This was related to the significant increase in leaf SPAD value and net photosynthetic rate of MDB1 and MDB2, which significantly increased the average fresh leaf weight, but there was no significant difference in yield between MDB1 and MDB2 treatments. Soil nutrient results showed that compared with CK, MD, MDB1 and MDB2 all significantly increased soil pH and available potassium content, but MD treatment significantly reduced soil organic matter, alkali-hydrolyzable nitrogen and available phosphorus content, which may be related to the utilization of soil organic matter by a large number of organic matter-decomposing microorganisms in the mushroom residue leading to nutrient consumption, while the combined application of high-dose biochar (MDB2) alleviated this effect, thus increasing organic matter content and alkali-hydrolyzable nitrogen content. PCA analysis based on soil bacterial OTUs found that there were significant differences in community structure among different treatments. Compared with CK, MD soil bacterial Shannon diversity index decreased and Simpson dominance index increased, while MDB1 and MDB2 significantly improved soil bacterial diversity. Compared with MD, they significantly increased beneficial plant growth-promoting bacteria such as Pedomicrobium, Streptomyces, MND1, Nocardioides and Pseudomonas. RDA analysis showed that soil alkali-hydrolyzable nitrogen was the main environmental factor affecting bacterial community structure. In summary, although mushroom residue application alone has yield-increasing potential, its effect on soil improvement is poor; combined application of biochar can significantly increase soil pH, available potassium content, improve soil microbial diversity, promote the enrichment of beneficial microorganisms, thereby increasing leaf chlorophyll content, enhancing leaf photosynthesis, and ultimately promoting a significant increase in P. amaryllifolius yield. Therefore, the synergistic application of biochar and mushroom residue is an efficient and safe soil improvement strategy, providing green and sustainable technical support for efficient cultivation of Pandanus.

This study represents sequencing of the chloroplast genome of the tea plant variety Zhuyeqi, with a focus on analyzing its structural characteristics, codon usage bias, and phylogenetic relationships. The results revealed that its chloroplast genome had 157 072 bp, with 135 functional genes annotated. The GC content in the IR region was found to be the highest (42.96%), and several intron-containing genes, such as clpP and ycf3, were identified. Codon usage bias analysis indicated a relatively weak bias, primarily driven by natural selection (contribution rate of 86.6%). Optimal codons were mostly A/U-ending, deviating from expectations based on mutational pressure. Phylogenetic analysis further confirmed that Zhuyeqi formed a highly supported monophyletic clade with cultivated types such as Pu-erh tea and Baihao tea, demonstrating close maternal genetic relationships. This study would provide important insights into the evolution of Theaceae species and the functional optimization of chloroplast genomes.