Biomass is a key factor in plant evolutionary adaptation and yield, and obtaining high-yield crop varieties is always a basic requirement for crop breeding. In this study, a mutant Mu with increased biomass was discovered during the tissue culture of Setaria viridis ME34, and the trait can be stably inherited to the next generation. Through the observation of the phenotype of S. viridis and statistical analysis of the agronomic traits of seedlings and adults, it was found that the biomass (fresh and dry weight) of the mutant seedlings and the adult plant height of S. viridis mutant was significantly higher than that of the wild-type plants, and the spike length and seed length were also significantly longer than those of the S. viridis wild-type plants, reaching a highly significant level. Transcriptome sequencing was performed on the leaves and stems of ME34 and Mu, and some genes were validated by RT-PCR. Differential expression gene analysis revealed that the genes related to nitrogen metabolism and regulation accounted for about 20% of the total differential genes. GO functional and KEGG enrichment analysis also revealed a close relationship between biomass and nitrogen metabolism and regulation. The DEGseq method was used to analyze the changes in the differentially expressed genes, and some related genes involved in nitrogen absorption, transport, assimilation, and reuse were obtained, such as nitrate transporter NRT, ammonium transporter AMT, nitrate reductase NR, nitrite reductase NiR, glutamate synthase GOGAT, NLP family transcription factors, and serine threonine protein kinase. Through the above research, important molecular basis and foundation are provided for the breeding work of crops such as foxtail millet.

Longan (Dimocarpus longan Lour.) is an important economic crop in tropical subtropical areas. Under normal circumstances, longan can become flowers only when induced by low temperature in winter together with appropriate measures to control the winter tips, but potassium chlorate, as the only known compound that can induce longan to become flowers in the opposite season, the anatomical process and physiological mechanism of the potassium chlorate-regulated flower formation are not clear, and the carbon and nitrogen nutrition is closely related to flower formation. Carbon and nitrogen nutrition are closely related to flower formation, therefore, analyzing the changes of carbon and nitrogen content of longan by potassium chlorate is also an important perspective to reveal the mechanism of flower formation. In this study, we used Shixia longan (Dimocarpus longan Shixia) as the test material, and induced the antiseasonal flower formation of longan by soil application of potassium chlorate to investigate the anatomical changes of the terminal buds of the antiseasonal longan during flower formation, and analyzed the changes in the C and N contents as well as the relationship between C/N and the development of the terminal buds. By observing the growth point of the terminal buds in the control group, which always showed a more pointed leaf bud state, the terminal buds after potassium chlorate treatment clarified the three stages of flower bud differentiation according to the changes in the morphology of the growth point: the stage of physiological differentiation of flower buds, the stage of inflorescence formation of flower buds, and the stage of floral organ formation. The carbon content of terminal buds treated with potassium chlorate showed a continuous increasing trend, while the carbon content of the control showed an increasing and then decreasing trend, the nitrogen content of both groups showed an increasing and then decreasing trend, and the C/N trend of the two groups showed a “stable-decreasing-increasing” trend. At the stage of flower bud physiological differentiation, the C/N content of terminal buds increased more than that of the control after KClO₃ treatment, while the N content of both groups did not change much. The C/N content of terminal buds increased from 22.82 to 23.41, while that of the control decreased from 22.82 to 22.63, showing a smooth trend in both groups. During the inflorescence formation stage of flower buds, the increase in total carbon content of terminal buds was smaller than that of the control, while the increase in total nitrogen content was larger than that of the control after potassium chlorate treatment; the C/N of terminal buds decreased from 23.41 to 17.65 after potassium chlorate treatment, while that of the control decreased from 22.63 to 20.29, and the decrease of terminal buds was larger after potassium chlorate treatment than that of the control. At the stage of inflorescence emergence, the whole carbon and nitrogen contents of terminal buds showed an increasing trend after potassium chlorate treatment, while the opposite was true for the control. The C/N of terminal buds increased from 17.65 to 21.44 after potassium chlorate treatment, while that of the control increased from 20.29 to 22.92, but the rate of increase of terminal buds was greater after potassium chlorate treatment than that of the control. This study reveals that a more than 21.47% increase in the C/N ratio of longan terminal buds is conducive to flowering. The application of potassium chlorate through soil leads to a continuous increase in total carbon content and an initial increase followed by a decrease in total nitrogen content in longan terminal buds, resulting in a significant rise in the C/N ratio, which is beneficial for the development of terminal buds towards floral formation.

Camellia oleifera is a significant woody oil tree species that is extensively cultivated in southern China. It displays a notable degree of diversity in phenotypic traits, such as fruit, leaf and tree shapes, etc.. In the present study, 100 C. oleifera seedling trees were collected and 33 phenotypic traits were subjected to the comprehensive evaluation. In the diversity analysis of quantitative traits, the coefficient of variation (CV) was ranged from 8.81% to 56.85%, with the number of flowers per unit area (NFPUA) exhibiting the greatest variability (56.85%), and the fruit shape index (FSI) demonstrated the least variability (8.81%). The diversity index of quantitative traits exhibited a range of 1.13 to 4.61, indicating a notable degree of genetic diversity in fruit and leaf traits. Cluster analysis classified the 100 germplasm accessions into five categories. The first category was characterized by dark fruit colour, a rounder fruit shape, and taller trees. The second category exhibited flattened fruit shape and heavier fruit weight with narrower tree cannopy. The third category was characterized by longer fruit shapes with heaviest single fruit weight, and smaller but denser tree canopies. The fourth category was distinguished by mainly round fruits, lighter single fruit weight, and larger leaf area. The fifth category exhibited elongated fruits with thicker peels and more opened tree canopy. Principal component analysis yielded 12 principal components, collectively accounted for 79.174% of the cumulative contribution rate, including traits such as fruit diameter, single fruit weight, and fresh seed weight. Based on the results of the principal component analysis, superior C. oleifera accessions were selected for further observation. This study demonstrated that C. oleifera germplasm resources in Hainan province exhibited a high level of phenotypic trait diversity. The research would provide a theoretical base for the genetic improvement of C. oleifera.

Helopeltis theivora Waterhouse belongs to the genus Helopeltis of the family Miridae of the order Hemiptera, and is one of the most important sap-sucking pests in the tropical tea plantations in Hainan, China. The nymphs and adults of H. theivora mainly damage by piercing and sucking in the young tissues of tea shoots, which causes the black brown spots that necrosis on the leaf and results in the reduction of tea yield and quality. The research on the H. theivora in Hainan tea region is still rare. In this paper, we first investigated the external morphological characteristics of H. theivora, then, the growth and development characteristics such as egg hatching, nymph molting, and adult emergence, as well as the behavioral characteristics including feeding, mating and oviposition were recorded and analyzed, respectively. The results showed that the egg of H. theivora was in a sausage shape, with two respiratory processes on the egg operculum at different length. The color of the freshly laid egg was white. It was then gradually transformed to the orange and ultimately exhibited the orange-red as it approached incubation. The nymphal stage was divided into 5 instars, the color of the freshly hatched nymph was orange-red, and then gradually turned to pale green and green. The adult H. theivora possessed a small head, an elongated beak, and two black compound eyes. The antennae presented filamentous, and the length was twice more than the body. The color of adult H. theivora was brown or yellowish brown. The duration of incubation of H. theivora was (53.25±9.00)min. The hatchability was very low while the rate of egg- hatching was only 69.9% under the laboratory conditions. The moulting of nymphs and the emergence of adults happened mainly on the back of leaves, hanging upside down, and the duration was (6.20±0.97)min and (8.40±1.33)min, respectively. Particularly, as approached to the molting and eclosion, the feeding frequency became significantly less and the activity became weaker. The H. theivora preferred to sucking the saps of the young leaves and stems of tea shoots, and the feeding time was mainly concentrated in the evening. The mating behavior of adults H. theivora mainly happened between 9: 00 and 10: 00 and between 17: 00 and 18: 00, and the duration of each mating was (117.75±18.70) min. In addition, when a female decided to refuse a male’s request for courtship, it generally rolled her abdomen inwards. The stage of the fertilized egg of H. theivora was short. During the oviposition, the female arched itsr abdomen, its head was downward, and the whole body was in a curvedly arched state. The oviposition site was mainly in the epidermis of the tender stems, while a small part of eggs was laid in the petiole and leaf vein. The egg stage was 6-8 days. The results of this study would provide a theoretical basis for the further study on the morphological identification and behavioral ecology of H. theivora in Hainan tea region.

Rubber tree latex metabolic processes are regulated by a variety of mechanisms, among which ubiquitination modification is the most significant. The phloem protein PP2 belongs to the F-box protein family and is specifically highly expressed in latex, which may be involved in the regulation of latex regeneration. In this study, bioinformatics and expression pattern analysis were conducted on 17 F-box members of the HbPP2 gene identified in the genome of Hevea brasiliensis. The results revealed that the majority of proteins encoded by the rubber tree PP2 genes were unstable hydrophilic proteins with molecular weights ranging from 9.402 to 61.206 kDa. Phylogenetic analysis showed that the 17 HbPP2 genes in the H. brasiliensis could be divided into three subgroups (Subgroup Ⅰ, Subgroup Ⅱ, Subgroup Ⅲ), in which HbPP2 members were completely absent in subgroup I. Analysis of cis-acting elements revealed that the rubber tree PP2 gene family contained diverse functional elements involved in growth and development regulation, hormone response, and light response. Subcellular localization analysis indicated that PP2 proteins were primarily localized in chloroplasts or cytoplasm. Tissue expression analysis showed that, except for some members with tissue-specific expression, most members of the rubber tree HbPP2 family were expressed in various tissues. In latex, the expression levels of six genes, HbPP2-B1, HbPP2-B1.1, HbPP2-B10.1, HbPP2-A13.2, HbPP2-B13 and HbPP2-A15.1, were relatively high, but tapping treatment significantly upregulated the expression of HbPP2-A13.2 and HbPP2-B13. This study would provide preliminary insights into the physicochemical and expression characteristics of the HbPP2 family members in the H. brasiliensis, laying a foundation for further research on the functions of this genes family in rubber trees latex synthesis and metabolism.

Mango (Mangifera indica L.), as a typical climacteric fruit, undergoes ripening and senescence processes closely related to ethylene. Ethylene-responsive factors (ERF) play crucial roles in plant growth, fruit ripening and ethylene signaling transduction. Mango variety Guifei was used, MiERF20, 492 bp long and encoding 163 amino acids, was cloned and analyzed. Bioinformatics analysis revealed that MiERF20 was an unstable, hydrophilic protein without signal peptides or transmembrane regions, containing 25 phosphorylation sites and one AP2 conserved domain. The secondary structure was dominated by 40.49% irregular coils, 33.13% α-helices, 16.56% extensions and 9.82% β-rotations. Its secondary structure comprised irregular coils, α-helices, extended chains, and β-turns, consistent with AP2 domain features. MiERF20 showed 83.89% homology with ERF20 of Lacertidae pistachio. Subcellular localization indicated that MiERF20 was located in the nucleus and possessed transcriptional activation activity. Prokaryotic expression assays demonstrated that the protein could be inducibly expressed in a prokaryotic system. Real-time fluorescence quantification showed that MiERF20 was ethylene-inducible, suggesting its role in ethylene-regulated fruit ripening. This study would provide a foundation for further analysis of the functions and regulatory mechanisms of ERF transcription factors during postharvest fruit ripening.

The total RNA of Aquilaria sinensis vitro roots was extracted using the EASYspin Plus Plant Rapid Extraction Kit after three consecutive generations of salt stress treatment, and sequenced using the HiSeq 2500 high- throughput sequencing platform, aiming at exploring the roles of miRNAs in the three generations of A. sinensis vitro roots under salt stress and the metabolic pathways that may be involved in the regulation, and providing references to reveal the mechanisms of A. sinensis. The miRNA expression profiles of the first, second and third generations were obtained by using the high-throughput sequencing platform and bioinformatics technology, and the differential miRNAs in the three generations of vitro roots were screened, and the target genes of the differential miRNAs were predicted, and then the target gene analysis was performed to obtain the miRNAs that might be involved in the secondary metabolites of A. sinensis and those that were related to the response to salt stress. The results showed that 508 known miRNAs and 764 new predicted miRNAs were detected in the first-generation samples; 444 known miRNAs and 673 new predicted miRNAs were detected in the second-generation samples; 904 known miRNAs and 1100 new predicted miRNAs were detected in the third-generation samples. A total of 59 differentially expressed miRNAs and 275 target genes were obtained from the three samples. The up-regulated miRNA target genes were mainly involved in flavonoid biosynthesis and glutathione metabolism, while the down-regulated miRNA target genes were mainly involved in phenylpropanoid biosynthesis, Plant hormone signal transduction, plant-pathogen interactions and other signaling pathways. The key miRNAs were selected for NR annotation, and it was found that miR8020-x and novel-m0628-5p might be involved in the synthesis of secondary metabolites in A. sinensis vitro roots, and miR7494-y, miR477-y, miR5185-y, miR7757-y, miR408-z, and novel-m0628-5p might be responded to A. sinensis vitro roots salt stress. In this study, we used high-throughput sequencing to obtain miRNA expression profiles of A. sinensis vitro roots under salt stress, and bioinformatics analysis to obtain miRNAs that may be involved in secondary metabolites of A. sinensis and those related to the response to salt stress. The results of the present study will help to enhance the understanding of the miRNA regulatory mechanisms of A. sinensis under salt stress conditions and provide a new pathway for the synthesis of secondary metabolites of A. sinensis.

Based on 24 phenotypic traits, statistical analysis, correlation analysis, principal component analysis and systematic cluster analysis were carried out on 187 pepper hybrid combinations introduced from different ecological regions in China to screen out the best hybrid combinations of pepper suitable for planting in Jiangxi. The Shannon-Weaver genetic diversity index of 12 descriptive traits was ranged from 0.36 to 1.95, with an average of 0.82. The genetic diversity index of fruit shape was highest (1.95). The variation coefficient of 12 quantitative traits was ranged from 16.61% to 84.48%, and the variation coefficient of single fruit weight was the largest. The genetic diversity index was ranged from 0.67 to 2.08, with an average of 1.80. Correlation analysis showed that the correlation coefficient (r_s) between single fruit weight and fruit diameter was the highest, reaching 0.86. In addition, yield was significantly positively correlated with fruit diameter, fruit flesh thickness and single fruit weight. Principal component analysis simplified the 24 traits index into 3 principal components, and the cumulative contribution rate reached 69.164%. The cluster analysis showed that the 187 hybrid combinations could be divided into 5 groups at 8.10 Euclidean-distance, and there were significant differences in single fruit weight, fruit color, fruit shape and plant height among the groups. After comprehensive scoring, 10 excellent hybrid combinations suitable for planting in Jiangxi were selected. The above results would provide scientific basis for the comprehensive evaluation, selection and application of pepper hybrid combination.

Gene TFL1 belongs to the phosphatidylethanolamine binding protein (PEBP) family and is closely related to plant flowering regulation. To explore the functions of TFL1 gene in Dendrobium hybrid, based on the transcriptome data of floral in Dendrobium hybrid, a TFL1 gene was cloned and named DenTFL1. And the bioinformatic analysis protein structure and subcellular localization prediction, expression patterns analysis were done to explored the functional of DenTFL1. The results showed that the full length of DenTFL1 cDNA sequence was 522 bp, encoding 173 amino acids. Bioinformatics analysis showed that the molecular formula of DenTFL1 was C₈₇₀H₁₃₅₄N₂₄₆O₂₄₉S₆, the theoretical relative molecular mass of the protein was 19.43 kDa, and the theoretical isoelectric point was 7.82, and the protein was hydrophilic and structurally stable. Subcellular prediction showed that it was located in the cytoplasm, without signal peptide and transmembrane domain. The secondary structure was dominated by 61.85% of random curl, also contained 23.70% of the extended chain, 14.45% of α-helix. The three-dimensional structural model was basically consistent with the secondary structure. The conserved domain analysis showed that DenTFL1 had a conserved PEBP domain and amino acid sequence alignment and phylogenetic tree analysis showed that DenTFL1 was closely related to D. nobile and D. thyrsiflorum. The constructed protein network showed that DenTFL1 mainly interacted with AT5G63440, LFY, SOC1, AGL24, AGL8. Expression analysis showed that DenTFL1 was expressed in all tissues of different development stages of Dendrobium hybrid, and had the highest expression level in the stems of young and mature plantlet and the flower stalks, and had a lower expression level in the roots of young plantlet and the leaves and roots of medium plantlets. Moreover, it had a high expression in different development stage of inflorescence except 3.0 cm long inflorescence. It also showed high expression in 7.0 mm and 9.0 mm width floral bud and the tissues of fully open flower, but expressed lower in the tissues of early development stages of floral bud. The research could provide a reference for the flowering regulation of Dendrobium hybrid, and add relevant information for the study of TFL1.

Mulberry is a fruit tree with rich nutrition and dual functions of food and medicine, which is deeply loved by consumers. The fragrance is a significant factor in the sensory quality of mulberries, playing a crucial role in consumer purchasing behavior. Mulberry Baichang is a unique variety that emits a strong, creamy fragrance, which has enormous potential market value. However, the key metabolites and mechanisms responsible for the formation of this fragrance are still unclear. In this study, we utilized GC-MS and RNA-seq technology to examine the volatile organic compounds (VOCs) and gene expression in Baichang and Hongchang, which lacking a distinct fragrance. The results showed that 661 volatile metabolites were detected in both varieties. Most of these were found in higher relative amounts in Baichang, with 47 types being present only in Baichang, suggesting a rich composition of VOCs in this variety. A total of 312 metabolites were identified as differential metabolites; combining the sensory annotation information and relative content of VOCs, 70 candidate VOCs were annotated as being related to the formation of “sweet, waxy, coconut and oily” sensations. These could potentially be the key metabolites contributing to the unique aroma of Baichang. The relative odor activity value (rOAV) analysis revealed that 5-hexyldihydro-2(3H)-furanone (also known as γ-decalactone) was the key VOC contributing to the formation of the special aroma of Baichang. Using RNA-seq, 19 key structural genes related to ester synthesis were screened, including AAT, ACX, ALDH, CYP, EHL, FAD, HPL and LOX. The high expression levels of these structural genes in Baichang may contribute to the unique creamy aroma of this variety; however, the underlying mechanisms require further investigation. This study would provide insights into the aroma differences among different kinds of mulberries.