Hasil untuk "Botany"

Ph. Gitta L. Coaker, Graduate Program Coordinator Theresa Garcia, Lead Faculty Advisor Johan Leveau et al.

M. L. C. Vieira, Luciane Santini, A. L. Diniz et al.

Abstract Microsatellites or Single Sequence Repeats (SSRs) are extensively employed in plant genetics studies, using both low and high throughput genotyping approaches. Motivated by the importance of these sequences over the last decades this review aims to address some theoretical aspects of SSRs, including definition, characterization and biological function. The methodologies for the development of SSR loci, genotyping and their applications as molecular markers are also reviewed. Finally, two data surveys are presented. The first was conducted using the main database of Web of Science, prospecting for articles published over the period from 2010 to 2015, resulting in approximately 930 records. The second survey was focused on papers that aimed at SSR marker development, published in the American Journal of Botany's Primer Notes and Protocols in Plant Sciences (over 2013 up to 2015), resulting in a total of 87 publications. This scenario confirms the current relevance of SSRs and indicates their continuous utilization in plant science.

Hany M. El-Naggar, Shimaa M. Ali, Amira R. Osman

Abstract The postharvest life of cut flowers is limited, which is a major challenge and varies greatly depending on plant varieties, cut flower stage, flower length of the harvested shoots, and storage conditions including postharvest treatments. As a result, improving the vase life and quality of cut flowers in regulating postharvest characteristics and overcoming these challenges is critical to the horticulture business. Novel engineered nanocomposites were created and tested for possible impacts on flower bud opening, postharvest life extension, longevity regulation, and preservation and enhancement of the strength and appearance of cut flowers. The experiment was conducted as a factorial experiment using a completely randomized design (CRD) with two factors. The first factor was two holding solutions (without or with sucrose at 20 gL−1). The second factor was 12 pulsing treatments for 24 h; distilled water as a control, 75 ppm GA3, multi-walled carbon nanotubes MWCNTs at 10, 20, 30, 40, and 50 ppm, and MWCNTs (10, 20, 30, 40, and 50 ppm)/GA3 (75 ppm) composites; each treatment had 3 replicates, for a total of 72 experimental units. In the present study, gibberellic acid (GA3) was synthesized in functionalized (MWCNT/GA3 composites) as a novel antisenescence agent, and their effect on the vase life quality of cut rose flowers Rosa hybrida cv. ‘Moonstone’ was compared by assaying several parameters critical for vase life. The adsorption of GA3 on MWCNTs was proven by performing FTIR spectroscopy which ensures that the formation of the MWCNTs/GA3 composite preserves the nanostructure and was examined by high-resolution transmission electron microscopy (HR-TEM). The results revealed that sucrose in the holding solution showed a significant increase in fresh weight, flower diameter, and vase life by 10.5, 10.6, and 3.3% respectively. Applying sucrose with MWCNTs 20 ppm/GA3 75 ppm composites or MWCNTs 20 ppm alone, was critical for the significant increase in flower opening by 39.7 and 28.7%, and longevity by 34.4 and 23.2%, respectively, and significantly increased chlorophyll a, b, total chlorophyll, anthocyanin, total phenolic content, and 2,2-Diphenyl-1-picrylhydrazyl scavenging activity as compared to the control.

Nancy Pérez-Mejía, María Luisa Villarreal, Jessica Nayelli Sánchez-Carranza et al.

<i>Bursera fagaroides</i>, popularly used in México, possesses bioactive lignans. These compounds are low in the bark, and its extraction endangers the life of the trees. The aim of the present investigation was to search for alternative sources of cytotoxic compounds in <i>B</i>. <i>fagaroides</i> prepared as leaves and in vitro callus cultures. The friable callus of <i>B. fagaroides</i> was established using a combination of plant growth regulators: 4 mgL⁻¹ of 2,4-dichlorophenoxyacetic acid (2,4-D), 1 mgL⁻¹ Naphthaleneacetic Acid (NAA) and 1 mgL⁻¹ Zeatin. The maximum cell growth was at day 28 with a specific growth rate of μ = 0.059 days⁻¹ and duplication time td = 11.8 days. HPLC quantification of the dichloromethane callus biomass extract showed that Scopoletin, with a concentration of 10.7 µg g⁻¹ dry weight, was the main compound inducible as a phytoalexin by the addition of high concentrations of 2,4-D, as well as by the absence of nutrients in the culture medium. In this same extract, the compounds γ-sitosterol and stigmasterol were also identified by GC-MS analysis. Open column chromatography was used to separate and identify yatein, acetyl podophyllotoxin and 7′,8′-dehydropodophyllotoxin in the leaves of the wild plant. Cytotoxic activity on four cancer cell lines was tested, with PC-3 prostate carcinoma (IC₅₀ of 12.6 ± 4.6 µgmL⁻¹) being the most sensitive to the wild-type plant extract and HeLa cervical carcinoma (IC₅₀ of 72 ± 5 µgmL⁻¹) being the most sensitive to the callus culture extract.

Ruijie Wang, Meng Zhang, Hui Wang et al.

Abstract Background As a vital type of noncoding RNAs, circular RNAs (circRNAs) play important roles in plant growth and development and stress response. However, little is known about the biological roles of circRNAs in regulating the stability of male fertility restoration for cytoplasmic male sterility (CMS) conditioned by Gossypium harknessii cytoplasm (CMS-D2) cotton under high-temperature (HT) stress. Results In this study, RNA-sequencing and bioinformatics analysis were performed on pollen grains of isonuclear alloplasmic near-isogenic restorer lines NH [N(Rf 1 rf 1 )] and SH [S(Rf 1 rf 1 )] with obvious differences in fertility stability under HT stress at two environments. A total of 967 circRNAs were identified, with 250 differentially expressed under HT stress. We confirmed the back-splicing sites of eight selected circRNAs using divergent primers and Sanger sequencing. Tissue-specific expression patterns of five differentially expressed circRNAs (DECs) were also verified by RT-PCR and qRT-PCR. Functional enrichment and metabolic pathway analysis revealed that the parental genes of DECs were significantly enriched in fertility-related biological processes such as pollen tube guidance and cell wall organization, as well as the Pentose and glucuronate interconversions, Steroid biosynthesis, and N-Glycan biosynthesis pathways. Moreover, we also constructed a putative circRNA-mediated competing endogenous RNA (ceRNA) network consisting of 21 DECs, eight predicted circRNA-binding miRNAs, and their corresponding 22 mRNA targets, especially the two ceRNA modules circRNA346-miR159a-MYB33 and circRNA484-miR319e-MYB33, which might play important biological roles in regulating pollen fertility stability of cotton CMS-D2 restorer line under HT stress. Conclusions Through systematic analysis of the abundance, characteristics and expression patterns of circRNAs, as well as the potential functions of their parent genes, our findings suggested that circRNAs and their mediated ceRNA networks acted vital biological roles in cotton pollen development, and might be also essential regulators for fertility stability of CMS-D2 restorer line under heat stress. This study will open a new door for further unlocking complex regulatory mechanisms underpinning the fertility restoration stability for CMS-D2 in cotton.

Paola Fernanda Agüero-Martínez, Leonardo Cardozo, Carlos A. Gómez et al.

<i>Chenopodium hircinum</i>, the putative wild ancestor of quinoa, is a source of traits that could improve the tolerance of crop quinoa to high temperatures. However, seeds of <i>C. hircinum</i> have physiological dormancy (PD), which is an obstacle for plant propagation and use in breeding programs. We studied the intraspecific variability in morpho-anatomical traits of embryo covering structures and their association with PD. We also evaluated the effects of different dormancy-breaking treatments on PD alleviation and germination. Seeds were dispersed with a remnant perianth and a persistent pericarp that could be removed by scraping. The seed coat was formed by palisade cells impregnated with tannins, and the seed contained a thin layer of peripheral endosperm surrounding the embryo. In our investigation, the thickness of the pericarp (P) and/or seed coat (SC) varied among populations. Populations with higher P and/or SC thickness showed lower percentages of germination and water absorption. The combined dormancy-breaking treatment (bleach + perforated coverings + gibberellic acid) promoted dormancy release and increased germination. <i>C. hircinum</i> seeds showed non-deep physiological dormancy. Based on previous knowledge about quinoa, and our results, we conclude that embryo coverings, especially the seed coat, have an important role in dormancy control, imposing a mechanical restraint on radicle emergence.

P. Pablo Ferrer-Gallego, Jacek Wajer

A neotype for the widespread and ecologically important plant Lavandula pedunculata Mill. (Lamiaceae) [≡ Stoechas pedunculata (Mill.) Cav.] is designated. The neotype is seleccted from a modern specimen preserved at the VAL herbarium (VAL 174683) and collected in Spain.

Estefany Goncalves, Ileana Herrera, Jake Alexander et al.

Alien plant species are colonizing high-elevation areas along roadsides. In this study, we evaluated whether the distributions of alien plants in the central Chilean mountains have reached climatic equilibrium (i.e., upper distribution limits consistent with their climatic requirements). First, we evaluated whether the upper elevational limits of alien plants changed between 2008 and 2018 based on the Mountain Invasion Research Network (MIREN) database. Second, we compared the observed upper elevational limits with the upper limits predicted by each species’ global climatic niche. On average across species, the upper elevation limit did not change between 2008 and 2018. However, most species maintained the same limit or shifted downward, while only 23% of the species shifted upwards. This lack of change does not mean that the species’ distributions are in equilibrium with the climate, because the observed upper limit was lower than the limit predicted by the global niche model for 87% of species. Our results suggest that alien species in this study region may not only be climate-limited, but could also be limited by other local-scale factors, such as seed dispersal, intermittent disturbance rates, soil type and biotic interactions.

Qingqing Shen, Zhenfeng Qian, Tianju Wang et al.

The NAC (NAM, ATAF1/2, and CUC2) transcription factor family is one of the largest families unique to plants and is involved in plant growth and development, organs, morphogenesis, and stress responses. The NAC family has been identified in many plants. As the main source of resistance genes for sugarcane breeding, the NAC gene family in the wild species Saccharum spontaneum has not been systematically studied. In this study, 115 SsNAC genes were identified in the S. spontaneum genome, and these genes were heterogeneously distributed on 25 chromosomes. Phylogenetic analysis divided the SsNAC family members into 18 subgroups, and the gene structure and conserved motif analysis further supported the phylogenetic classification. Four groups of tandemly duplicated genes and nine pairs of segmentally duplicated genes were detected. The SsNAC gene has different expression patterns at different developmental stages of stems and leaves. Further qRT–PCR analysis showed that drought, low-temperature, salinity, pathogenic fungi, and other stresses as well as abscisic acid (ABA) and methyl jasmonate (MeJA) treatments significantly induced the expression of 12 SsNAC genes, indicating that these genes may play a key role in the resistance of S. spontaneum to biotic and abiotic stresses. In summary, the results from this study provide comprehensive information on the NAC transcription factor family, providing a reference for further functional studies of the SsNAC gene.

Y. Sanath K. De Silva, Uma Maheswari Rajagopalan, Hirofumi Kadono et al.

Reliable seed screening that can speedily detect qualities such as dormancy and seed germination can be of great significance in improving plant growth, crop yield, and quality. On the other hand, Optical Coherent Tomography (OCT) has been extensively used as a potential tool in visualizing structures of biological objects, especially the retina. However, its role in visualizing temporal changes that accompany these structures as speckle noise remains relatively underexplored. The present study of biospeckle OCT or bOCT demonstrates the potential of speckles in plant physiological studies. In this paper, the potential of bOCT in speedily investigating the positive and negative phenotyping of increasing Zn concentrations on lentil seed (Lens culinaris) germination and seedling growth were demonstrated. Lentil seeds were exposed to three different Zn concentrations of 0 (control), 5, 10, and 100 mg/L for 24 h, and the structural OCT images were acquired to calculate the temporal fluctuations in the image as a quantity called the average speckle contrast (γ). The average speckle contrast was calculated after 6 h, 12 h, and 24 h of exposure to different concentrations. Statistically significant differences were observed even within 12 h of exposure under all the Zn treatments compared to control. In comparison, the conventional measurements of germination rate, root and shoot lengths, and fresh and dry weights of seedlings took nearly 48 h to observe significant changes. Furthermore, the Zn uptake measurements were significant for all the tested concentrations after seven days of exposure. Further, bOCT results showed a clear concentration dependent effect with 5, 10 mg/L producing positive effects, while a high concentration of 100 mg/L showing a detrimental effect on seed germination and seedling growth. Thus, the current study results imply that bOCT can be used to investigate the positive and negative effects of increasing Zn concentrations on seed germination and seedling growth at an early stage before germination.

Jia-Huan Shang, Wen-Jie Sun, Hong-Tao Zhu et al.

Background: Root rot is a serious destructive disease of Panax notoginseng, a famous cultivated araliaceous herb called Sanqi or Tianqi in Southwest China. Methods: The chemical substances of Sanqi rot roots were explored by chromatographic techniques. MS, 1D/2D-NMR, and single crystal X-ray diffraction were applied to determine the structures. Murine macrophage RAW264.7 and five human cancer cell lines were used separately for evaluating the antiinflammatory and cytotoxic activities. Results and Conclusion: Thirty dammarane-type triterpenes and saponins were isolated from the rot roots of P. notoginseng. Among them, seven triterpenes, namely, 20(S)-dammar-25-ene-24(S)-hydroperoxyl-3β,6α,12β,20-tetrol (1), 20(S)-dammar-3-oxo-23-ene-25-hydroperoxyl-6α,12β,20-triol (2), 20(S)-dammar-12-oxo-23-ene-25-hydroperoxyl-3β,6α,20-triol (3), 20(S)-dammar-3-oxo-23-ene-25-hydroperoxyl-12β,20-diol (4), 20(S),24(R)-epoxy-3,4-seco-dammar-25-hydroxy-12-one-3-oic acid (5), 20(S),24(R)-epoxy-3,4-seco-dammar-25-hydroxy-12-one-3-oic acid methyl ester (6), and 6α-hydroxy-22,23,24,25,26,27-hexanordammar-3,12,20-trione (7), are new compounds. In addition, 12 known ones (12–16 and 19–25) were reported in Sanqi for the first time. The new Compound 1 showed comparable antiinflammatory activity on inhibition of NO production to the positive control, whereas the known compounds 9, 12, 13, and 16 displayed moderate cytotoxicities against five human cancer cell lines. The results will provide scientific basis for understanding the chemical constituents of Sanqi rot roots and new candidates for searching antiinflammatory and antitumor agents. Keywords: 20,24-epoxylated, Dammarane-type triterpenes, Hydroperoxylated, Panax notoginseng, Inhibition of NO production

Shakira Johnson, Dan Jones, Amali H. Thrimawithana et al.

Venturia nashicola, the cause of scab disease of Asian pears, is a host-specific, biotrophic fungus. It is restricted to Asia and is regarded as a quarantine threat outside this region. European pear displays nonhost resistance (NHR) to V. nashicola and Asian pears are nonhosts of V. pyrina (the cause of European pear scab disease). The host specificity of these two fungi is likely governed by differences in their effector arsenals, with a subset hypothesized to activate NHR. The Pyrus-Venturia pathosystem provides an opportunity to dissect the underlying genetics of nonhost interactions in this potentially more durable form of resistance. The V. nashicola genome will enable comparisons to other Venturia spp. genomes to identify effectors that potentially activate NHR in the pear scab pathosystem.

Viviana Valdez, Shirley Moncayo, Xavier Cornejo et al.

En el presente trabajo se realizó el tamizaje fitoquímico, cuantificación de flavonoides y fenoles totales y la evaluación de la actividad antioxidante y antibacteriana de los extractos etanólicos obtenidos de hojas de Hibiscus escobariae, Loxopterygium huasango y Croton ferrugineus, contra tres bacterias Gram Positivas (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes) y tres Gram negativas (Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus). Para el análisis de las muestras se realizó el tamizaje fitoquímico por el método de Domínguez, la cuantificación de flavonoides por el método colorimétrico cloruro de aluminio, la cuantificación de fenoles totales por el método Folin-Ciocalteu, actividad antibacteriana por ensayos de difusión por disco y actividad antioxidante mediante la técnica DPPH. En el tamizaje fitoquímico los flavonoides y taninos se presentaron en mayor cantidad, mientras que los alcaloides, quinonas, antraquinonas, esteroides y saponinas estuvieron presentes en menor proporción. El contenido de flavonoides varió de 100,95 ± 1,73 a 995,42 ± 3,16 mg CE / g extracto en H. escobariae y L. huasango y el contenido de fenoles varió de 10,17 ± 0,22 a 314,72 ± 1,91 mg GAE/ g extracto en Croton ferrugineus y L. huasango que también obtuvo la mejor actividad antibacteriana frente a las cepas evaluadas con CMI que varían de 2.5 a 5 mg/mL y la mejor actividad antioxidante con IC50 de 0,1 mg/m y de 0,7 mg/mL para Croton ferrugineus con una diferencia significativa p<0.05. Estos resultados son los primeros reportados los que servirán como línea base para estudios posteriores.

Rashmi Chaudhary, Yasmin Janjhua, Nikhil Sharma et al.

Engagement of rural youth in agriculture based livelihood activities is gaining attention as a strategy to mitigate current problem of unemployment due to employment potential of these activities. Nonetheless, there have been evidences about declining youth participation in agriculture based livelihood activities. The present study investigated the factors determining rural youth participation in agriculture based livelihood activities. Examination of a sample of 250 youth respondents identified; agricultural knowledge, availability of land, interest in agriculture, fertile soil, favourable environment & temperature, availability of different types of soil, good transportation facilities and well connectivity as some of the factors determining rural youth participation in agriculture-based livelihood activities in the study area. The overall results for predominant agricultural based activities in which youth participate indicates that youths in the study area are not significantly engaged in agriculture based livelihood activities. However crop farming and livestock rearing are the two major activities in which they are involved. The results of the study will have some useful implication for the policy makers and it is recommended that all stakeholders must make efforts to create favourable environment for increasing youth participation in agriculture based livelihood activities.

S. P. Singh, V. K. Dua, S. K. Sharma et al.

A field experiment was conducted during rabi seasons (winter) of 2011–12 and 2012–13 to assess the effect of planting dates, weed control and varieties on productivity and profitability of potato under Gwalior region of Central India. The field was infested with Chenoporium album (Bathua), Chenopodium murale (Kharbathua), Celosia argentia (Safed) and Trianthema monogyna (Patharchata). Highest weed density (176 sq m-1) was recorded with 15th September planted crop which was significantly higher over all other planting dates. Delaying date of planting from 15th September to 15th November increased tuber yield in weedy check (10.8 to 30.1 t ha-1) and weed control (12.6 to 38.5 t ha-1) treatments which show that at optimum temperature crop competes in better way with weeds. Among different varieties tested, Kufri Jyoti showed least competition with weeds. Highest tuber yield was recorded with 15th November planted crop. Among varieties, Kufri Khyati gave highest tuber yield (30.1 t ha-1) under weed control condition and Kufri Surya (22.6 t ha-1) under weedy check condition. Nutrient uptake by weeds was highest in early and late planting situations compared to main crop. Delaying date of planting increased water use efficiency from 27 kg tuber ha-1-mm to 128 kg ha-1-mm. Hence, Kufri Surya may be preferred for planting over Kufri Khyati and Kufri Jyoti in early plantings where adoption of weed control is bare minimum. Extra early planting in the month of September should be avoided to increase efficiency of applied nutrient and water inputs. Unused inputs damage environment in addition to decreasing profit from cropping.

Fawzy Mahmoud SALAMA, Monier Mohammed ABD EL-GHANI, Ahmed Abd El Rahman AMRO et al.

The present study provides an analysis of the floristic composition, habitat types, vegetation structure and species diversity, elucidating the role of the environmental factors that affect species distribution in Kharga Oasis, Western Desert, Egypt. The vegetation was sampled from 89 permanently visited stands in 12 sites situated along N - S line transect across the oasis, and extending for about 185 km to cover as much as possible the physiognomic variation in habitats. Four main habitats were recognized and forming concentric zones (from inside to outside): farmlands and date-palm orchards represent the inner zone, the waste-salinized lands (not saltmarshes) in the middle zone, and the surrounding (bounding) desert in the outer zone. A total of 122 species from 35 families and 102 genera represented the flora of the study area. Poaceae, Asteraceae and Fabaceae were the major families, which constituted 47% of the total flora. Classification using Bray-Curtis cluster analysis produced 4 vegetation groups (A - D); each can be linked to a certain habitat. The arrangement of habitat zones along the first DCA axis can be noticed: outer zone (bounding desert), middle zone (waste-salinized lands) and inner zone (arable lands). On the other hand, farmlands and date-palm orchard groups were separated from each other along the second DCA axis. The relationship between the vegetation and soil variables was studied using Canonical Correspondence Analysis (CCA); it was indicated the most important environmental gradients those control the vegetation composition and the distribution pattern of species in Kharga Oasis, which were mainly related to gradients in soil moisture content and fine fractions. The present situation of Kharga Oasis urges the conservation of some old historic wells and the naturally growing open dom-palm forests before vanishing due to high human activities in the area.