Landscape Plants Research Articles

A New Species of Ampelovirus Detected in Persea lingue (Ruiz & Pav.) Nees ex Kopp, a Common Tree of the Threatened Chilean Sclerophyll Forest

Biotic and abiotic stress seriously affects the development of plants, leading to the death of a significant number of plants in natural landscapes. Over the last twelve years, the central zone of Chile has been under an intensive drought, affecting the species inhabiting the Chilean Mediterranean forest, which is classified as a biological hotspot. In this context, our group started a small survey to monitor the presence of intracellular pathogens that may be infecting the plants, increasing the damage caused by the water deprivation. Several plants of one species, Persea lingue, showed symptoms of interveinal yellowing and leaf curling. RNA-seq analyses of one of these samples showed the presence of a long contig with high coverage only in symptomatic plants. Phylogenetic analysis and the molecular features indicated that it was a new species of the Ampelovirus genus. RT-PCR analyses determined the presence of the virus only in symptomatic plants of the same natural preserve.

A Case Study of Leaf Wettability Variability and the Relations with Leaf Traits and Surface Water Storage for Urban Landscape Plants

Leaf wettability, the affinity of a leaf surface to water droplets, affects the interactions between leaves and external environments. This study aimed to determine the interspecific and seasonal variabilities of leaf wettability across 30 common landscape plants, and their relationships with leaf functional traits, surface micromorphology and rainfall interception in Hefei city, China. Results indicated that leaf wettability was species-specific, and the adaxial and abaxial contact angles ranged from 63° to 134° and 66° to 134°, respectively, with the adaxial surface proving more wettable. Leaf wettability gradually increased from spring to winter. Classification of life forms revealed that there were no significant wettability differences among trees, shrubs and herbs, and between evergreen and deciduous plants, but deciduous plants’ wettability increased more significantly in winter. Leaf wettability was not significantly correlated with any leaf functional traits. Single surface microscopic parameters also had low correlations with leaf wettability. Instead, the low-wettability species were found to possess more prominent epidermis cells, dense waxy layers or trichomes on leaf surfaces. Leaf wettability was the best predictor of surface rainwater storage within all functional traits. Our results highlighted that leaf wettability was variable between different species and growth periods due to micromorphological differences, and significantly affected rainfall interception at the leaf scale, which may have great significance for evaluating plant hydrological function in urban areas.

Study on Xiurong academy landscape based on regional culture

Regional culture has been regarded as the historical record of human activities and the carrier of the cultural inheritance of a particular region during the past decades. The unique regional culture of Shanxi had influenced the landscape construction of Xiurong Academy. In this paper, research of the regional cultural perspective on the overall layout of Xiurong Academy, the creation and analysis of characteristic regional landscapes, and the cultural and garden landscapes of the academy has been conducted through literature research, field research, and other methods. The results show that Xiurong Academy has high reference value in the layout of the academy, historical culture, architectural characteristics, and landscape features of the academy in northern Shanxi. The landscape construction of Xiurong Academy conforms to the regional characteristics of its location. Its unique detailed design is reflected in the architecture, courtyard layout, and plant construction of Xiurong academy. It is valuable to provide some reference for the scientific protection and utilization of Xiurong Academy, even for other similar landscape research through our research to uncover and illustrate its building structure and plant landscape.

The complete chloroplast genome of Eurya rubiginosa var. attenuata H. T. Chang (Pentaphylacaceae)

Eurya rubiginosa var. attenuata is a valuable multiuse tree with a long history of use in China. It has great economic and ecological importance and is used for landscape and urban planting, soil improvement, and raw materials for food production. However, genomic studies of E. rubiginosa var. attenuata are limited. Meanwhile, the classification of this taxon is controversial. In this study, the complete plastome of E. rubiginosa var. attenuata was successfully sequenced and assembled. The chloroplast genome is 157,215 bp in length with a 37.3% GC content. The chloroplast genome structure includes a quadripartite structure comprising a pair of inverted repeat (IR) sequences of 25,872 bp, a small single-copy (SSC) region of 18,216 bp, and a large single-copy (LSC) region of 87,255 bp. The genome contains 128 genes, including 83 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic inference based on complete plastome analysis showed that E. rubiginosa var. attenuata is closely related to E. alata and belongs to the family Pentaphylacaceae, which differs from the results of the traditional Engler system. The chloroplast genome sequence assembly and phylogenetic analysis enrich the genetic resources of Pentaphylacaceae and provide a molecular basis for further studies on the phylogeny of the family.

Ethnobotany of wild edible plants in Soro District of Hadiya Zone, southern Ethiopia

BackgroundDespite their paramount importance all over the globe in supporting food security, information about wild edible plants is generally patchy. In this study, we investigated the wild edible plants used by the local people in the Soro District of Hadiya Zone, southern Ethiopia. The main purpose of the study was to document and analyze the indigenous and local knowledge of the people on their abundance, diversity, use and management.Methods and materialsPurposive sampling and systematic random sampling were used to identify informants who can give information about the wild edible plants of the area. Data were collected by interviewing 26 purposively sampled key informants and 128 systematically randomly sampled general informants using semi-structured interviews. Guided observations and 13 focus group discussions (FGDs) consisting of 5–12 participants/discussants at each FGD session were also undertaken. Statistical analyses (mainly descriptive statistics approaches) and common analytical tools of ethnobotany including informant consensus, informant consensus factor, preference ranking, direct matrix ranking, paired comparison and index of fidelity level were applied to the data sets.ResultsA total of 64 wild edible plant species belonging to 52 genera and 39 families were recorded. All of these species are indigenous, 16 are new additions to the database and seven of them, including Urtica simensis and Thymus schimperi, are endemic to Ethiopia. In about 82.81% of the species, the edible plant part is also used in the Ethiopian traditional herbal medicine. It is striking to see that almost all wild edible plants recorded from the study area are nutraceutical plant species, serving multiple roles as food and therapeutic sources for the local people. We recorded five growth habits of 34.38% trees, 32.81% herbs, 25% shrubs, 6.25% climbers, and 1.56% liana. We found the Flacourtiaceae, Solanaceae, and Moraceae to be families that represented more species (4 each), followed by Acanthaceae, Apocynaceae, Amaranthaceae, and Asteraceae, which accounted for 3 species each. Fruits (53.13%) and leaves (31.25%) were consumed in more proportions than other edible parts (15.63%); mostly the ripe, raw fruit is eaten upon simple processing, followed by leaves eaten after boiling, roasting and cooking.ConclusionThe frequency and intensity of consumption of these plants varied significantly (P < 0.05) with gender differences, key and general informants, and people’s religious backgrounds. We postulate that priority setting for in situ and ex situ conservation of multipurpose wild edible plants in human-inhabited landscapes is essential to warrant sustainable use and conservation of the species as well as the use of new modes of application and valorization.

Pollinators differ in their contribution to the male fitness of a self-incompatible composite.

Reproductive fitness in plants is often determined by the quantity and quality of pollen transferred by pollinators. However, many fitness studies measure only female fitness or rely on proxies for male fitness. Here we assessed how five bee taxon groups affect male fitness in a prairie plant by quantifying pollen removal, visitation, and siring success using paternity assignments and a unique pollinator visitation experiment. In Echinacea angustifolia, we measured per-visit pollen removal for each pollinator taxon and estimated the number of pollen grains needed for successful ovule fertilization. Additionally, we directly measured pollinator influence on siring by allowing only one bee taxon to visit each pollen-donor plant, while open-pollinated plants acted as unrestricted pollen recipients. We genotyped the resulting offspring, assigned paternity, and used aster statistical models to quantify siring success. Siring success of pollen-donor plants differed among the five pollinator groups. Nongrooming male bees were associated with increased siring success. Bees from all taxa removed most of the flowering head's pollen in one visit. However, coneflower-specialist bee Andrena helianthiformis removed the most pollen per visit. Female fitness and proxy measures of male fitness, such as pollinator visitation and pollen removal, did not align with our direct quantifications of male fitness. Our results illustrate the need for more studies to directly quantify male fitness, and we caution against using male fitness proxy measures. In addition, conservation efforts that preserve a diverse pollinator community can benefit plants in fragmented landscapes.

Excessive Use of Water and Fertilizer by Homeowners: Why It Happens, How It Affects the Environment, and How the Nursery Industry and Extension Outreach Can Help

Abstract Despite global concerns regarding climate change, one thing remains constant: homeowners want gardens and landscapes that serve them functionally and aesthetically. The strong affinity homeowners have for their land can lead to excessive use of water and fertilizer. This literature review explores the relationships between homeowners and their residential landscapes and the efforts that can be made to address misuse and overuse of resources. Governmental organizations should work together with community groups, nursery and landscape associations, and university Extension faculty to understand homeowner desires and behaviors before instituting policies regarding resource use that are unpopular, resented, and ignored. Networking between the nursery industry and university Extension faculty and Master Gardener volunteers can provide educational opportunities for homeowners to understand and implement more sustainable landscape practices as well as showcasing ornamental landscape plants that can help meet both personal aesthetics and resource conservation goals.

Principles and Practice of Landscape Design: An Application of Traditional Chinese Landscape Painting

As a unique artistic form, traditional Chinese landscape painting has aesthetic value and a close relationship with garden design. This study mainly explores the principles and practices of landscape design based on traditional Chinese landscape painting. Firstly, it introduces the brief history of the development of traditional Chinese landscape painting and its relationship with garden design. Then, it analyzes the characteristics of traditional landscape painting and garden design principles. Then, the application of traditional Chinese landscape painting in landscape design was analyzed, including landscape layout, plant selection, and matching, as well as the design of buildings and structures. In conclusion, applying traditional Chinese principles in modern landscapes presents inherent challenges that demand thoughtful consideration. As contemporary spaces evolve and adapt to changing needs, integrating traditional elements may face obstacles such as conflicting design philosophies, space constraints, and technological advancements. Addressing these challenges requires a nuanced approach that preserves the essence of traditional principles while accommodating the demands of modern living. This section explores strategies and innovative solutions to overcome these challenges and successfully apply traditional principles in the design of modern landscapes.

Growth characteristics and post trimming regrowth potential of tropical and sub-tropical landscape hedge plants in response to spacing

Spacing of landscape plants is one of the factors determining the outcome of a design in terms of canopy formation which is one of the variables for aesthetic appearance in terms of shapes and forms. This study was conducted between September 2016 and September 2017, to determine the appropriate intra-row spacing for five plant species in hedge formation. The plant species used were Duranta erecta, Hamelia patens, Ficus retusa, Buxus sempervirens and Acalypha wilkesiana. Transplanting was done at intra-row spacing of 30, 40, 50 and 60cm and a constant inter-row spacing of 100cm. The experiment was a Randomized Complete Block Design in split plot arrangement with three replicates. Plant height, number of leaves, number of branches and canopy space, as indices of species suitability for use as hedge, were measured fortnightly. Plant regrowth and aesthetic characteristics were assessed after periodic trimming. H. patens and B. sempervirens species had the tallest plants. B. sempervirens and D. erecta produced the highest number of leaves while D. erecta and H. patens had the highest number of branches. D. erecta had significantly (p&lt;0.05) the fastest post-trimming shoot regrowth rate relative to other species following the 1st and 2nd trimming (25 and 28 WAT respectively). The effect of spacing on shoot regrowth length was significant after the 3rd, 4th and 5th trimmings (31, 34 and 37 WAT respectively). The highest shoot regrowth height was recorded at 40cm spacing followed by 30cm intra row spacing. All species responded best at 50cm intra-row spacing for the number of branches and canopy space as well as early hedge formation. The study concluded that B. sempervirens was suitable for ideal hedging at 40cm intra-row spacing while A. wilkiesiana and H. patens were only suitable as informal hedges. Hence, B. sempervirens species is recommended as the ideal hedge plant choice based on its early regrowth after trimming, high leaf and branch production as well as overall speed in hedge formation at 31WAT.

RECYCLING DOMESTIC SEWAGE SLUDGE TO AGRICULTURAL AND FARMING AREAS IN LINE WITH SUSTAINABLE DEVELOPMENT GOALS (SDG)

Corresponding to the rapid increase in population, the increase in the number of domestic wastewater treatment plants, as well as the increase in domestic sludge levels above acceptable levels, pave the way to utilize sewage sludge in a variety of different applications and usage areas. Using sewage sludge in agriculture, landscape plant cultivation, and other agricultural areas has a number of advantages, including the ability to make rational use of waste without damaging the environment as well as delivering fertilizer benefits to the plant due to the high organic matter content of the wastewater sludge. Aside from these advantages, the most serious drawbacks of waste sewage are pathogenic bacteria, heavy metal contamination, and the presence of potentially hazardous compounds. The use of existing waste in the soil in appropriate proportions and in methods that are compatible with ecological life, on the other hand, will contribute to the fertilization of agricultural areas, providing an alternative to the fertilizer industry. The Sustainable Development Goals (SDGs), also known as the Global Goals, are a global call to action to end poverty, safeguard the environment, and guarantee that everyone lives in peace and prosperity. It is expected that this research will help to promote awareness about the reuse of waste within the context of a sustainable environment, as well as shed light on the application of sewage sludge to agricultural fields in accordance with the Sustainable Development Goals. Furthermore, the support for sewage sludge recycling in agricultural regions for long-term development goals is shown.

The Complete Genome Sequence, Molecular Detection, and Anatomical Analysis of Hibiscus Chlorotic Ringspot Virus Infecting Hibiscus rosa-sinensis in Peninsular Malaysia

Hibiscus rosa-sinensis is the national flower of Malaysia and is widely cultivated as landscape planting across the nation. In 1995, Hibiscus chlorotic ringspot virus (HCRSV) was reported for the first time in Malaysia. Until today, there have been no follow-up studies on the viral infection in the plant, yet the virus symptom of chlorotic spots has been observed throughout the Hibiscus population. Therefore, this study aimed to report the complete genome sequence of the HCRSV, validate a molecular detection tool for its diagnosis, and measure the impact of the virus symptom and infection in H. rosa-sinensis. This study reported the complete genome of the HCRSV through RNA sequencing. The phylogenetic analysis of the HCRSV isolated from different geographical sources and several other related viruses was performed to confirm its identity and classification. Additionally, primers based on the genome sequence were designed and used for RT-PCR to detect the presence of the virus in symptomatic leaves, further confirming the HCRSV identity and presence. Meanwhile, the impact of the virus was measured by examining the anatomical and morphological changes in the leaf structure of symptomatic samples. Light microscopy and scanning electron microscopy were used to examine potential adaptations and comparisons between the leaf structures of healthy and infected samples, especially in the leaf lamina, petiole, and midrib cells. The results confirmed the complete genome sequence of the HCRSV, its molecular detection strategy, and the impact of the viral infection on Hibiscus leaves in Peninsular Malaysia. This study is beneficial for the management strategy of the virus and for protecting an important plant in the nation.

Morphological Features and Landscaping Suitability of &lt;em&gt;Syzygium zeylanicum&lt;/em&gt; (L.) DC. var. &lt;em&gt;lineare&lt;/em&gt; Trees from the Belihuloya Region of Sri Lanka

Purpose: Syzygium zeylanicum (L.) DC. grows naturally in some of the Asian countries including Sri Lanka. In the Belihuloya region the S. zeylanicum trees are naturally grown with specific characteristics than the rest of the country and in other countries. It is scientifically identified as a different variety as S. zeylanicum (L.) DC. var. lineare (Wall.). There are no studies specifically focused on this tree in Sri Lanka. This study has focused on the studying morphological characters and suitability of S. zeylanicum var. lineare as a landscaping plant. Research Method: Morphological characteristics of leaves, flowers, and fruits (pericarp thickness, seed diameter, width, length and weight of fruit) were recorded from randomly selected trees. Landscaping suitability was evaluated using measurements of shading under the tree canopy, the air pollution tolerance index of the plant and the general community perception. Findings: Leaf (area, length, width, petiole length, internodal length, and leaf-veins-angle), flower (length and width of style, filament, floral cup and length of pedicel and anther) and fruit morphological parameters were significantly different among plants except for the width of anther, floral cup and fruit length. The average shading was 88.7%. Most of the surveyed persons preferred to grow the plants as a landscaping plant (47%). Twenty-six percent (26%) of the respondents indicated that it could be used as a good shade tree. Further, respondents identified fruit appearance, tiny leaves, and branching patterns are features that would give high landscaping value to the plant. The air pollution tolerance index was 9.72 in the control site and 9.32 in the polluted site. Research Limitations: Selecting the same ageing plants for the study was difficult. Originality/ Value: The plant can be used as a landscaping plant, mainly as a shade plant. The plant is sensitive in a polluted environment and can be used as an air pollution indicator.

MORPHOGENIC RESPONSE FROM LEAF EXPLANT OF Dendranthema grandiflora VAR MICROMARGARA

&lt;p class="Default"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Chrysanthemum is one of the most popular landscape plants worldwide. Introducing desirable traits into this plant by conventional breeding has limitations due to cross-incompatibility. An approach to this problem is the introduction of resistance or tolerance traits via plant genetic transformation. &lt;em&gt;In vitro&lt;/em&gt; regeneration of plants is necessary for implementing genetic transformation systems; therefore, regeneration via morphogenesis is required before any genetic transformation attempt. &lt;strong&gt;Objective&lt;/strong&gt;: To induce morphogenesis from the leaf explant of &lt;em&gt;Dendranthema grandiflora&lt;/em&gt; var Micromargara. &lt;strong&gt;Methodology&lt;/strong&gt;: Micropropagation from node cuttings was induced from node cuttings of 3 cm in length from 6 months-old plants that were used as explants to produce seedlings as source explants. Morphogenesis experiments were done using leaf segments of 1 cm&lt;sup&gt;2&lt;/sup&gt; from 8-weeks-old &lt;em&gt;in vitro &lt;/em&gt;seedlings. The explants were transferred to basal medium Murashige and Skoog at 4.4 gL&lt;sup&gt;-1&lt;/sup&gt; supplemented with different plant growth regulators. During the morphogenic process, leaves samples were collected to detect which morphogenic process was induced. &lt;strong&gt;Results: &lt;/strong&gt;Node cuttings culture on Murashige and Skoog medium at 3.3 gL&lt;sup&gt;-1&lt;/sup&gt; supplemented with benzylaminopurine at 2.2 µM yielded a vegetative growth increase from 1 to 7 shoots, 2 to 12 leaves per node cutting, and the stem length of 3 to 9.5 cm. The leaf explant induced three ways of &lt;em&gt;in vitro&lt;/em&gt; morphogenesis: direct and indirect roots organogenesis (rhizogenesis) and, shoot organogenesis. Direct rhizogenesis was induced in plant growth regulator-free Murashige and Skoog medium (18 roots/explant). Indirect rhizogenesis from leaf explant was less efficient than direct rhizogenesis, get obtaining six roots per leaf explant cultured on Murashige and Skoog medium at 4.4 g L&lt;sup&gt;-1 &lt;/sup&gt;supplemented with 0.4 µM thidiazuron and 4.5 µM 2,4-dichlorophenoxyacetic acid, and three roots per leaf explant cultured on Murashige and Skoog medium supplemented with 0.4 µM thidiazuron and 9.05 µM 2,4-dichlorophenoxyacetic acid. Indirect shoot organogenesis was induced from leaf explants cultured on Murashige and Skoog at 4.4 g L&lt;sup&gt;-1&lt;/sup&gt; supplemented with 13.32 µM benzylaminopurine and 4.83 µM naphthalene acetic acid; 50% of explants with callus formed shoots (2 shoots/leaf explant). Through histological analysis it was possible to verify that the morphogenic response obtained was organogenesis. &lt;strong&gt;Implications:&lt;/strong&gt; Regeneration of &lt;em&gt;Dendranthema grandiflora&lt;/em&gt; var. Micromargara established herein will allow improvement of the variety through techniques of genetic transformation mediated by Agrobacterium and any other strategy to incorporate or silence genes of interest in the plant. &lt;strong&gt;Conclusion&lt;/strong&gt;: The high capacity to induce roots of &lt;em&gt;Dendranthema grandiflora&lt;/em&gt; var Micromargara, may provide an efficient model for further investigating the mechanism of rhizogenesis from leaf explants cultured without plant growth regulators.&lt;/p&gt;

Plants in Design

Plants in Design: A Guide to Designing With Southern Landscape Plants Brad E. Davis and David Nichols. University of Georgia Press, 2021. ![Figure][1]</img> I have taught introductory plants classes to landscape architecture students for ten years and have always struggled to find a good

Biological Parameters of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) Differ When Reared on Different Crapemyrtle Hosts

Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae Kuwana), a fast-spreading invasive insect, has been causing damage to popular landscape plants in at least 17 states in the United States since 2004. This invasive insect has a list of documented plant hosts in ∼23 genera, which includes its primary hosts, crapemyrtles (Lagerstroemia spp.), as well as other important plant species, such as pomegranates, apple, and the native plant American beautyberry. Previous studies have shown CMBS causes different levels of feeding damage among its plant hosts, while the underlining plant defense mechanisms toward CMBS attacks remain elusive. A better understanding of plant–CMBS interactions and how CMBS performs under different plants (e.g., a susceptible vs. a resistant host) can provide valuable guidance for integrated pest management. Therefore, in this study, we conducted the age-stage, two-sex table study analysis to evaluate the biological parameters of CMBS on different species or cultivars of crapemyrtle under laboratory conditions (25 °C and 250 μmol·m−2·s−1 light with a photoperiod of 12 hours:12 hours (light:dark). Crapemyrtle bark scale development was found to be greatly influenced by the hosts. This study aims to provide important biological and ecological data on CMBS using a comprehensive life table study to gain a thorough understanding of its development, survival, and fecundity on different crapemyrtle species or cultivars.

Application of digital technology in environmental art design

Abstract In recent years, digital technology has rapidly penetrated various industries and brought various opportunities for developing these industries. Based on two digital technologies, BP neural network and the Gray Wolf algorithm, this article analyzes the application of digital technology in environmental art design at Xi’an Eurasian National University, taking environmental art design as an example. The article uses these two algorithms to analyze the site and design principles of the campus, followed by detailed design and consideration of the campus environment design, mainly from greenery design, groundscape and road pavement design, and campus landscape lighting design. The analysis of the collected data in this paper shows that students’ satisfaction with the central teaching area is generally low, at around 20%, and the satisfaction with the northwest teaching area is the highest, all above 40%, up to 61%. The students’ satisfaction with the plant landscape on the campus was generally at a medium level. However, the satisfaction level for loblolly pine is not very high, and overall is around 30%, while the satisfaction level for the cedar is high, and everyone’s satisfaction is higher than 60%. Therefore, this paper takes the students’ satisfaction with the campus landscape environment into consideration in the landscape design, which is conducive to achieving the perfect integration of landscape art design and ecological environment and achieving the realistic goal of both aesthetic and environmental protection.

Biological soil crusts decrease infiltration but increase erosion resistance in a human-disturbed tropical dry forest.

Under continuous human disturbance, regeneration is the basis for biodiversity persistence and ecosystem service provision. In tropical dry forests, edaphic ecosystem engineering by biological soil crusts (biocrusts) could impact regeneration by influencing erosion control and soil water and nutrient fluxes, which impact landscape hydrology, geomorphology, and ecosystem functioning. This study investigated the effect of cyanobacteria-dominated biocrusts on water infiltration and aggregate stability in a human-modified landscape of the Caatinga dry forest (NE Brazil), a system characterized by high levels of forest degradation and increasing aridity. By trapping dust and swelling of cyanobacterial filaments, biocrusts can seal soil surfaces and slow down infiltration, which potentially induces erosion. To quantify hydraulic properties and erosion control, we used minidisc-infiltrometry, raindrop-simulation, and wet sieving at two sites with contrasting disturbance levels: an active cashew plantation and an abandoned field experiencing forest regeneration, both characterized by sandy soils. Under disturbance, biocrusts had a stronger negative impact on infiltration (reduction by 42% vs. 37% during regeneration), although biocrusts under regenerating conditions had the lowest absolute sorptivity (0.042 ± 0.02 cm s-1/2) and unsaturated hydraulic conductivity (0.0015 ± 0.0008 cm s-1), with a doubled water repellency. Biocrusts provided high soil aggregate stability although stability increased considerably with progression of biocrust succession (raindrop simulation disturbed: 0.19 ± 0.22 J vs. regenerating: 0.54 ± 0.22 J). The formation of stable aggregates by early successional biocrusts on sandy soils suggests protection of dry forest soils even on the worst land use/soil degradation scenario with a high soil erosion risk. Our results confirm that biocrusts covering bare interspaces between vascular plants in human-modified landscapes play an important role in surface water availability and erosion control. Biocrusts have the potential to reduce land degradation, but their associated ecosystem services like erosion protection, can be impaired by disturbance. Considering an average biocrust coverage of 8.1% of the Caatinga landscapes, further research should aim to quantify the contribution of biocrusts to forest recovery to fully understand the role they play in the functioning of this poorly explored ecosystem.

Leaf morphology, genetic analysis and low temperature requirement for flowering of Verbascum blattaria

AbstractVerbascum blattaria L., commonly known as moth mullein, naturalized in the USA that produces white or yellow flowers could be considered as a potential ornamental plant. However, genetic characterization using molecular markers and leaf morphology, colourimetric analysis and flowering of V. blattaria influenced by low temperature treatments was not investigated to evaluate as a potential horticultural and landscape plant use. The basal leaves developed during the rosette-growth stage were oblanceolate with an obtuse leaf apex and incisions at the margin. Leaves produced on the stem during the reproductive development were ovate or lanceolate with an obtuse or acute leaf apex. Regardless of the colour of the petiole and leaf blade during the rosette-growth stage, there were no differences in the sequences of nuclear ribosomal ITS and chloroplast interspacer. All plants produced creamy white flowers with a purplish base corolla. All leaves formed during the vegetative and reproductive development were glabrous. Numerous stalked glandular trichomes were observed in the sepal, pedicel and bracts. Seeds started to germinate in 10 days at 25°C and reached the plateau in 30 days after sowing. The earliest flowering occurred in 131 days when the plants received 20 days of low temperature treatment (CD) (20 CD), producing 76 flowers, the highest number compared to the number of flowers produced by plants that received 0, 40 and 60 CD. Plants that received 20 CD exhibited early flowering, probably because of the early transition from vegetative growth to reproductive development, as judged by the short stem to the first flower.

First Report of Powdery Mildew Caused by Podosphaera xanthii on Cosmos bipinnata in Northeastern China.

Cosmos bipinnata (Cav.) is a common garden flowering plant with high ornamental value in China, and which is also widely distributed as a landscaping plant in northeastern China. During the summer of 2020, powdery mildew on C. bipinnata was observed in the garden of Best West Fortune Hotel, Harbin, Heilongjiang Province, China. More than 70% of plants in the garden were affected but at low severity, with only a few older leaves showing yellowing and wilting. Powdery mildew colonies began as small white spots on the upper surface of both young and mature leaves, and then spread to entire leaves. Conidia collected from infected plant tissues were ellipsoid-ovoid to barrel-shaped, with distinct fibrosin bodies visible in their cytoplasm, and measured 20 to 28 × 14 to 19 μm with a length/width ratio of 1.5 to 2.0 (n = 30). Conidiophores were unbranched, straight, 92 to 230 × 9 to 15 μm in size, and produced four to six immature conidia in chains (n = 30). Foot cells of conidiophores were cylindrical and 40 to 70 μm long, with light constriction at the basal septum, and followed by one to three short cells. Fungal hyphae were septate, branched, flexuous to straight, and up to 5 μm wide with indistinct to slightly nipple-shaped appressoria. Chasmothecia were absent in the collected infected samples. The morphological characteristics were consistent with Podosphaera xanthii reported by Braun and Cook (2012). For molecular identification, total gDNA was extracted from fungal colonies on infected leaves of three collections separately. For each DNA sample, the part of LSU and ITS regions were amplified using primers LSU1/LSU2 and ITS1/ITS4 (Scholin et al. 1994; White et al. 1990), respectively. BLASTn analysis of the 617bp (OP218411) and 563bp (MW166865) amplicons revealed 99.67% to 100% sequence identity with respective rDNA sequences of P. xanthii isolates present in GenBank (LSU: KY860729 and MK439610; ITS: MT242593 and MK439611). The phylogenetic trees were constructed using the neighbor-joining method in MEGA 5.0. Based on the ITS rDNA phylogenetic tree, the sequences retrieved from the specimens clustered within a strongly supported clade with P. xanthii. On the basis of morphological characteristics and molecular analysis, the isolate was identified as P. xanthii. Koch's postulates were carried out to prove the pathogenicity of the isolate. A pathogenicity test was performed by dusting conidia from an infected leaf onto young leaves of five healthy C. bipinnata plants in the greenhouse with five non-inoculated plants as a control. Powdery mildew symptoms were observed on inoculated leaves after 7 days of inoculation at 20/25°C (night/day) and 75% relative humidity, whereas control plants remained asymptomatic. The fungus on inoculated leaves was morphologically identified as that observed on the original diseased leaves. P. xanthii has been reported on several hosts in China, such as Zinnia elegans, Verbena bonariensis and Melothria indica (Fan et al. 2022; Hong et al. 2021; Zhong et al. 2022). To our knowledge, this is the first report of P. xanthii infecting C. bipinnata in northeastern China, and the information presented in this note will assist the horticultural industry on developing management strategies for this disease in China.

Nuclear OsFKBP20-1b maintains SR34 stability and promotes the splicing of retained introns upon ABA exposure in rice.

• Alternative splicing (AS) is a critical means by which plants respond to changes in the environment, but few splicing factors contributing to AS have been reported and functionally characterized in rice (Oryza sativa L.). Here, we explored the function and molecular mechanism of the spliceosome-associated protein OsFKBP20-1b during AS. • We determined the AS landscape of wild-type and osfkbp20-1b knockout plants upon abscisic acid (ABA) treatment by transcriptome deep sequencing. To capture the dynamics of translating intron-containing mRNAs, we blocked transcription with cordycepin and performed polysome profiling. We also analyzed whether OsFKBP20-1b and the splicing factors OsSR34 and OsSR45 function together in AS using protoplast transfection assays. • We show that OsFKBP20-1b interacts with OsSR34 and regulates its stability, suggesting a role as a chaperone-like protein in the spliceosome. OsFKBP20-1b facilitates the splicing of mRNAs with retained introns after ABA treatment; some of these mRNAs are translatable and encode functional transcriptional regulators of stress-responsive genes. In addition, interacting proteins, OsSR34 and OsSR45 regulate the splicing of the same retained introns as OsFKBP20-1b after ABA treatment. • Our findings reveal that spliceosome-associated immunophilin functions in alternative RNA splicing in rice by positively regulating the splicing of retained introns to limit ABA response.