Karyotype and nucleic acid content in Zantedeschia aethiopica Spr. and Zantedeschia elliottiana Engl.

Analysis of karyotype, nucleic deoxyribonucleic acid (DNA) content and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were performed in Zantedeschia aethiopica and Zantedeschia elliottiana. Mitotic metaphase in both species showed 2n=32. The chromosomes of both species were quite similar with medium length ranging from 1.55 ± 0.04 to 3.85 ± 0.12 μM in Z. aethiopica and 2.15 ± 0.04 to 3.90 ± 0.12 μM in Z. elliottiana. However, some differences were found in morphology and centromeric position among the chromosomes. Identification of individual chromosomes was carried out using chromosomes length, and centromeric positions. The karyotype of Z. aethiopica was determined to be 2n = 32 = 14 m + 18 sm and of Z. elliottiana to be 2n = 32 = 10 m + 22 sm. The 2C nuclear DNA content was found to be 3.72 ± 0.10 picograms (equivalent to 3638.16 mega base pairs) for Z. aethiopica and 1144.26 ± 0.05 picograms (equivalent to 1144.26 mega base pairs) for Z. elliottiana. Leaf protein analysis showed 11 and 9 bands for Z. aethiopica and Z. elliottiana, respectively, among which some were species specific. These results may provide useful information regarding Zantedeschia for the study of taxonomic relationships, genetics and breeding.Keywords: Zantedeschia, karyotype, mitotic metaphase, chromosomes, flow cytometr

Direct shoot organogenesis from petiole and leaf discs of Withania somnifera (L.) Dunal

An efficient and reproducible procedure is described for direct shoot regeneration using petiole and leaf explants of Withania somnifera (L.). The shoots were mainly induced from the distal end of the petiole, whereas in leaf explants, shoot regeneration was initiated from the basal part and wounded tissue. The regeneration medium that induced the highest numbers of shoots in the petiole and leaf explants was Murashige and Skoog (MS) medium supplemented with 2 mg/l N6-benzyladenine (BA) alone or with 0.1 mg/l a-naphthalene acetic acid (NAA). The frequency of shoot regeneration was greatly influenced by the type of explant, the carbon source, the orientation of the explant, and the basal medium used in the regeneration medium. Explants produced shoot buds and adventitious shoots within four weeks. Histological analysis of the regenerating shoots showed that the shoot buds emerged from sub epidermal parenchymal cells, with no intermediate callus formation. Plantlets were rooted on MS alone or MS containing different concentrations of 3-indolebutyric acid (IBA). The addition of 1 mg/l IBA to the medium was most effective in inducing root formation. The regenerated plantlets were acclimatized in the greenhouse and successfully transferred to the field, with a 90% survival rate. The acclimatized plants showed normal flowering and were not morphologically different from the seed-derived mother plants.Key words: Histology, medicinal plant, plant growth regulator, plant regeneration, Withania somnifera

Winter hardiness of \u3ci\u3eMiscanthus\u3c/i\u3e (III): Genome‐wide association and genomic prediction for overwintering ability in \u3ci\u3eMiscanthus sinensis\u3c/i\u3e

Overwintering ability is an important selection criterion for Miscanthus breeding in temperate regions. Insufficient overwintering ability of the currently leading Miscanthus biomass cultivar, M. ×giganteus (M×g) ‘1993–1780’, in regions where average annual minimum temperatures are −26.1°C (USDA hardiness zone 5) or lower poses a pressing need to develop new cultivars with superior cold tolerance. To facilitate breeding of Miscanthus, this study characterized phenotypic and genetic variation of overwintering ability in an M. sinensis germplasm panel consisting of 564 accessions, evaluated in field trials at three locations in North America and two in Asia. Genome‐wide association (GWA) and genomic prediction analyses were performed. The Korea/N China M. sinensis genetic group is a valuable gene pool for cold tolerance. The Yangtze‐Qinling, Southern Japan, and Northern Japan genetic groups were also potential sources of cold tolerance. A total of 73 marker–trait associations were detected for overwintering ability. Estimated breeding value for overwintering ability based on these 73 markers could explain 55% of the variation for first winter overwintering ability among M. sinensis. Average genomic prediction ability for overwintering ability across 50 fivefold cross‐validations was high (~0.73) after accounting for population structure. Common genomic regions for overwintering ability were detected by GWA analyses and a previous parallel QTL mapping study using three interconnected biparental F1 populations. One QTL on Miscanthus LG 8 encompassed five GWA hits and a known cold‐responsive gene, COR47. The other overwintering ability QTL on Miscanthus LG 11 contained two GWA hits and three known cold stress‐related genes, carboxylesterase 13 (CEX13), WRKY2 transcription factor, and cold shock domain (CSDP1). Miscanthus accessions collected from high latitude locations with cold winters had higher rates of overwintering, and more alleles for overwintering, than accessions collected from southern locations with mild winters

Genome biology of the paleotetraploid perennial biomass crop Miscanthus

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. x giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses

Biochemical and Physiological Changes during Early Adventitious Root Formation in Chrysanthemum indicum Linné Cuttings

Chrysanthemum indicum is an important ornamental and medicinal plant that is often difficult to propagate commercially because of its poor germination and low seed viability. This plant is mostly propagated by cutting, but the rooting is slow and non-uniform. The present investigation evaluated the regeneration capacity of stem cutting by examining the influence of auxins, growth medium, temperature, and explant type on adventitious root formation in C. indicum. The auxin-treated cuttings were planted in different growth substrates under greenhouse conditions. Among the different auxins tested, indole-3-butyric acid (IBA) more effectively induced roots. The cutting position of stock plants influenced rooting capacity. Cutting the stock plants from the apical region enhanced root number and length in the explants. Among the different explant types, apical stem cuts with 2000 ppm IBA produced a significantly higher number of adventitious roots when grown in vermiculite and perlite (V + P) at a ratio of 1:1 at 25 °C. High-performance liquid chromatography (HPLC) analysis revealed that protocatechuic acid, gentisic acid, chlorogenic acid, biochanin A, salicylic acid, caffeic acid, glycitein, and luteolin were the most dominant phenolic compounds present in C. indicum. These results indicate that IBA treatment promoted the synthesis and accumulation of phenolic compounds in C. indicum stem cuttings at the time of root formation. The present results demonstrate that applying auxins is essential for early root initiation and higher rooting success and thus may be beneficial for vegetative C. indicum propagation

Influence of Harvesting Time on Phenolic and Mineral Profiles and Their Association with the Antioxidant and Cytotoxic Effects of Atractylodes japonica Koidz

Plant phytochemical accumulation is influenced by various external factors that change with the seasons (e.g., harvesting time). Atractylodes japonica, an important medicinal plant rich in bioactive compounds, is used to treat several human diseases. We analyzed the influence of harvesting time on phenolic compound concentration and antioxidant activity of A. japonica roots. We investigated the correlation between phenolic compound and minerals contents and antioxidant activity in different harvests. Total phenolic and flavonoid contents varied significantly with the harvesting time. Liquid chromatography–mass spectrometry/mass spectrometry (LC–MS/MS) analysis revealed significant changes in the concentration of various phenolics between harvests. The content of different types of phenolics were significantly higher in the samples collected in October. Among them, chlorogenic acids (133,833.30 µg/g dry weight of root extract) were the most dominant phytochemical compounds detected. Samples harvested in October had higher concentrations of flavonoids, including rutin, orientin, vitexin, and apigenin. Roots harvested in October had a significantly higher (p < 0.05) antioxidant activity than that of those harvested later. Root mineral concentrations also varied with the harvest time. The analysis revealed that macro elements such as Ca ad Mg contents were significantly increased with delaying harvesting time, whereas a different trend was observed for the microelements including Fe, Cu, Al, and As contents in the October harvest. We also found a significant relationship between antioxidant activity and phenolic compound content. The most abundant minerals (Ca, Mg, Mn, Fe, and Al) correlated positively with the antioxidant activity indicating that these elements and compounds may be associated with the A. japonica antioxidant potential. Furthermore, A. japonica root extracts inhibited NIH/3T3 cellular proliferation in a season- and dose-dependent manner. Hence, harvesting time influenced the antioxidant properties and phenolic compound accumulation of A. japonica roots. These results indicate that the harvesting time is essential for obtaining the specific phytochemicals

Profiling of Phenolic Compounds Composition, Morphological Traits, and Antioxidant Activity of Miscanthus sacchariflorus L. Accessions

Miscanthus sacchariflorus is a potential source of sustainable biofuel and other bioactive compounds. The high adaptive range of M. sacchariflorus may cause variation in its morphological traits and phytochemical composition. Although some metabolites have been reported from M. sacchariflorus, little is known about its phenolic compound composition and antioxidant or oxidant properties. This study evaluated the morphological traits, antioxidant properties, and phenolic compound profile of M. sacchariflorus collected from various regions of China, Korea, Japan, and Russia. The antioxidant potential of the leaf extracts of various accessions of M. sacchariflorus was estimated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and 2,2′-azinobis 3-ethylbenzothiazoline-6-sulfonate (ABTS). An extensive study of the antioxidant activity and phenolic compounds of M. sacchariflorus obtained from different locations in four different countries could provide a comprehensive catalogue of the phytoconstituents and antioxidant properties of M. sacchariflorus accessions to consumers and nutraceutical industries. A total of 22 phenolic compounds were identified and quantified, among which p-coumaric acid, ferulic acid, p-hydroxybenzoic acid, chlorogenic acid, vitexin, and luteolin were the most dominant phytochemical compounds detected in the majority of the accessions. The antioxidant potential (DPPH) of the leaf extracts of all of the accessions ranged from 28.85 ± 1.53 µg mL−1 in MS-447 to 99.25 ± 1.63 µg mL−1 in MS-190. The antioxidant properties (ABTS) of the leaf extracts of all accessions ranged from 25.65 ± 2.06 in MS-258 to 83.62 ± 2.02 in MS-271. Pearson’s correlation analysis showed a significant and positive correlation between antioxidant activity and total phenolic content, and total flavonoid content varied widely among M. sacchariflorus accessions from the four geographical study regions. A strong and positive association was observed between DPPH with total phenolic content and total flavonoid content. Moderately positive correlations were observed between DPPH scavenging activity with gentisic acid, p-hydroxybenzoic acid, chlorogenic acid, p-coumaric acid, rutin, and quercetin (r = 0.385, r = 0.379, r = 0.362, r = 0.353, r = 0.490, and r = 0.372, respectively), suggesting that phenolic compounds are major contributors to the antioxidant potential of M. sacchariflorus. Thirty-two accessions collected from four different countries (China, Korea, Japan, and Russia) were characterized for 17 quantitative morphological traits. A wide range of diversity was observed in the morphological traits, with plant height ranging from 18.00 ± 1.00 cm to 163.20 ± 4.00 cm. Plant height was significantly correlated with biomass yield (fresh weight; r = 0.439, p < 0.05) and also had moderately positive correlations with culm length (r = 0.356, p < 0.05). Culm length was moderately correlated with the biomass yield fresh weight (r = 0.419*, p < 0.05) and the biomass yield dry weight (r = 0.425*, p < 0.05); however, it exhibited weak and negative correlations with compressed plant circumference (CCirc) (r = −0.374, p < 0.05) and total culm node number (TCmN) (r = −0.440, p < 0.05). Principal components analysis was performed to assess the variation in 17 morphological traits in 32 accessions of M. sacchariflorus. The first two principal components explained 51.24% of the morphological variations. A dendrogram generated from unweighted pair group method with arithmetic mean (UPGMA) clustering based on morphological characters was not found to be consistent with another dendrogram based on phytochemicals. In both cases, the number of studied accessions collected from different geographical regions grouped into two major groups. However, no clear correlation between these two different approaches was found. The substantial variation in the morphological traits, bioactive properties, and phenolic compounds among the accessions may provide useful information for breeding programs attempting to obtain M. sacchariflorus varieties with improved phenolic compounds traits and improved bioactive properties

Allelopathic Potential of Phenolic Compounds in Secale Cereale Cultivars and Its Relationship with Seeding Density

In this study, we investigated the allelopathic effect of Secale cereale cultivars on different weeds that grow in the cultivated fields of Perilla frutescens. Two S. cereale cultivars, Paldong and Singhi, were used to test the allelopathic effect on in vitro grown Digitaria ciliaris, Chenopodium album, Amaranthus lividus, Portulaca oleracea, Pinellia ternata and Commelina communis. The results indicated that S. cereale extracts affect callus growth of weeds in terms of fresh weight and percentage of growth inhibition. The inhibitory effects of both S. cereale cultivars combined with grass cover extracts were higher than using grass weeds alone. Concentrations of all identified phenolic compounds were significantly higher in the leaves extracts of Paldong compared to Singhi. Particularly, syringic acid in leaves extract of the Paldong cultivar were 12.87-fold higher than in the Singhi cultivar. The other predominant phenolic compounds such as salicylic acid, p-coumaric acid, vanillic acid, and p-hydroxybenzoic acids were 3.30, 4.63, 3.11, and 1.28 times higher, respectively, in the leaves extracts of Paldong compared to Singhi. Principal component analysis (PCA) results indicated that the composition of phenolic compounds was significantly related to cultivar types and plant parts used. In addition, biomass increase caused increased weed inhibitory capacity of S. cereale both in tillage and no-tillage regimes. These results suggest that the biomass of cover crops negatively influenced weed density

Biochemical and Physiological Changes during Early Adventitious Root Formation in <i>Chrysanthemum indicum</i> Linné Cuttings

Chrysanthemum indicum is an important ornamental and medicinal plant that is often difficult to propagate commercially because of its poor germination and low seed viability. This plant is mostly propagated by cutting, but the rooting is slow and non-uniform. The present investigation evaluated the regeneration capacity of stem cutting by examining the influence of auxins, growth medium, temperature, and explant type on adventitious root formation in C. indicum. The auxin-treated cuttings were planted in different growth substrates under greenhouse conditions. Among the different auxins tested, indole-3-butyric acid (IBA) more effectively induced roots. The cutting position of stock plants influenced rooting capacity. Cutting the stock plants from the apical region enhanced root number and length in the explants. Among the different explant types, apical stem cuts with 2000 ppm IBA produced a significantly higher number of adventitious roots when grown in vermiculite and perlite (V + P) at a ratio of 1:1 at 25 °C. High-performance liquid chromatography (HPLC) analysis revealed that protocatechuic acid, gentisic acid, chlorogenic acid, biochanin A, salicylic acid, caffeic acid, glycitein, and luteolin were the most dominant phenolic compounds present in C. indicum. These results indicate that IBA treatment promoted the synthesis and accumulation of phenolic compounds in C. indicum stem cuttings at the time of root formation. The present results demonstrate that applying auxins is essential for early root initiation and higher rooting success and thus may be beneficial for vegetative C. indicum propagation