In recent years, various mulberry leaf dishes have gradually gained in popularity. The harvesting period of mulberry leaves and the preparation of dried samples are critical for the retention of flavonoid content and activity. In this study, changes in flavonoid levels in mulberry leaves during their growth period (3–6 months), and the effects of four different drying methods [sun drying (SD), air drying (AD), oven drying (OD), and freeze drying (FD)] on flavonoid accumulation and antioxidant capacity were determined. The results showed that mulberry leaves grown for 6 months had higher levels of flavonoids, and different drying methods could significantly affect the flavonoid levels and antioxidant capacity of the leaves. Air drying and FD were the best methods in terms of retaining the antioxidant activity of flavonoids, although AD had lower operating costs than FD in the production process. Therefore, to obtain a high flavonoid content and maximum antioxidant activity, AD is recommended for mulberry leaves.

Cnidoscolus aconitifolius (Mill.) I.M. Johnst is a multipurpose woody plant. In this study, an in vitro efficient propagation system of stem segment explants derived from field-grown C. aconitifolius plants was established for the first time. The sterilization effect, axillary bud initiation, and proliferation efficiency of stem segments were evaluated. The results showed that the sterilization time of 0.1% mercuric chloride, the concentration of Plant Preservative Mixture (PPM), the pretreatment method, and the sampling season had significant effects on the sterilization of stem segments (p < 0.05). The type of medium and plant growth regulators (PGRs) affected the initiation of axillary buds, and the proliferation efficiency was significantly affected by PGRs. The results showed that the best sterilization method for stem segment explants was as follows: a pretreatment by rinsing with running water for 120 min, soaking in 75% ethanol for 50 s, soaking in 0.1% mercuric chloride for 10 min, and medium supplemented with 3 mL/L PPM. When inoculated on the medium in spring, the contamination rate was as low as 25.56%. The optimal initiation medium for axillary buds in stem segments was half-strength Murashige and Skoog (1/2 MS) medium supplemented with 0.5 mg/L 6-benzyladenine (6-BA). The induction rate was as high as 93.33%, and the mean length of axillary buds was 2.47 cm. The optimal proliferation medium was 1/2 MS medium supplemented with 4.0 mg/L 6-BA and 0.2 mg/L indole-3-butyric acid (IBA). The induction rate was up to 80.00%, the total proliferation coefficient was 4.56, and the net proliferation coefficient was 5.69. The 1/2 MS medium supplemented with 0.1 mg/L 6-BA and 1.5 mg/L indole-3-acetic acid (IAA) was most conducive to the elongation of the adventitious shoot, and the adventitious shoot of approximately 1 cm reached 1.93 cm after culturing for 14 days. The best medium for adventitious shoot rooting was 1/2 MS medium supplemented with 0.1 mg/L α-naphthalene acetic acid (NAA), the highest rooting rate was 82.00%, and the survival rate of transplanting was over 90%.

Antibiotic resistance genes (ARGs) are considered environmental pollutants posing a potential human health risk. Silage is an important and traditional feed, mainly for ruminants.

Background: Toonais a critical genus in the Meliaceae, and the plants of this group are an asset for both restorative and restorative purposes, the most flexible of which areToona sinensisandToona ciliata. To concentrate on the advancement of mitochondrial(Mt) genome variety inT.sinensisandT.ciliata, the Mt genomes of the two species were sequenced in high throughput independently, after de novo assembly and annotation to construct a Mt genome map for comparison in genome structure. Find their repetitive sequences and analyze them in comparison with the chloroplast genome, along with Maximum-likelihood(ML) phylogenetic analysis with 16 other relatives.Results: (1) T. sinensisandT.ciliataare both circular structures with lengths of 683482 bp and 68300 bp, respectively. They share a high degree of similarity in encoding genes and have AT preferences. All of them have the largest Phe concentration and are the most frequently used codons. (2) Both of their Mt genome are highly preserved in terms of structural and functional genes, while the main variability is reflected in the length of tRNA, the number of genes, and the value of RSCU. (3)T. siniensisandT. ciliatawere detected to have 94 and 87 SSRs, respectively, of which mononucleotides accounted for the absolute proportion. Besides, the vast majority of their SSRs were found to be poly-A or poly-T. (4)10 and 11 migrating fragments were identified in the comparison with the chloroplast genome, respectively. (5) In the ML evolutionary tree,T.sinensisandT.ciliataclustered individually into a small branch with 100% support, reflecting two species ofToonaare very similarly related to each other.Conclusions: This research provides a basis for the exploitation ofT.sinensisandT.ciliatain terms of medicinal, edible, and timber resources to avoid confusion; at the same time, it can explore the evolutionary relationship between theToonaand related species, which does not only have an important practical value, but also provides a theoretical basis for future hybrid breeding of forest trees, molecular markers, and evolutionary aspects of plants, which has great scientific significance.

Background: Broussonetia papyrifera (L.) L’Hér. ex Vent. has the characteristics of strong stress resistance, high crude protein content, and pruning tolerance. It is an ecological, economic, and medicinal plant. Polyploid plants usually perform better than their corresponding diploid plants in terms of nutrients, active substances, and stress resistance. Results: In this study, the leaves, calli, and seeds of diploid B. papyrifera were used for tetraploid induction by colchicine. The induction effect of colchicine on B. papyrifera was summarized through the early morphology, chromosome count and flow cytometry. It was concluded that the best induction effect (18.6%) was obtained when the leaves of B. papyrifera were treated in liquid MS (Murashige and Skoog) medium containing 450 mg·L^-1 colchicine for 3 d. The comparative analysis of the growth characteristics of diploid and tetraploid B. papyrifera showed that tetraploid B. papyrifera has larger ground diameter, larger stomata, thicker palisade tissue and thicker sponge tissue than diploid B. papyrifera. In addition, the measurement of photosynthetic features also showed that tetraploids had higher chlorophyll content and higher photosynthetic rates. Conclusion: This study showed that tetraploid B. papyrifera could be obtained by treating leaves, callus and seeds with liquid and solid colchicine, but the induction efficiency was different. Moreover, there were differences in stomata, leaf cell structure and photosynthetic features between tetraploid B. papyrifera and its corresponding diploid. The induced tetraploid B. papyrifera can provide a technical basis and breeding material for the creation of B. papyrifera germplasm resources in the future.

Paper mulberry (Broussonetia papyrifera) is a tree species that has many economic, ecological, and social uses. This study developed an efficient protocol for regenerating shoots from leaf explants using Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators (PGRs), which play vital roles in shoot regeneration. The best result, 86.67% induction frequency and 4.35 shoots per explant, was obtained in the MS medium containing 2.0 mg/L N6-benzyladenine (BA) and 0.05 mg/L indole-3-butyric acid. The effects of explant age, orientation, and genotype were also investigated. Explants from young leaves had a greater regeneration frequency than those from old leaves, and the results were better when the distal end of the leaf explant contacted the medium versus the proximal end. Approximately 70.96% of the shoots rooted well in the MS medium containing 0.4 mg/L α-naphthalene acetic acid (NAA). Although some genotypes achieved poorer results, the regeneration protocol is still applicable for mass multiplication and genetic transformation.