Stock Plants Research Articles

A mammalian herbivore selects local and cooler provenance trees in a restoration common garden experiment: implications for community‐assisted migration efforts

Rapid changes in climate have the potential to alter habitats faster than evolution may respond, leading to maladapted tree populations. Assisted migration may help foundation tree species persist in future climates by identifying populations and genotypes that are robust to expected climate change‐induced alterations. Importantly, community‐assisted migration accounts for impacts of those populations and genotypes on the broader community, including herbivores, often adapted to local plants. These impacts have been examined in arthropod communities, but few studies have assessed mammals, and fewer still have leveraged an experimental design to disentangle genetic contributions to herbivore selection among genotypes and populations. We tested whether North American porcupine (Erethizon dorsatum) browsing on Fremont cottonwood (Populus fremontii) is under genetic control in a common garden to uncouple genetic and environmental contributions on browse selection. Porcupines selected trees from climatically similar and cooler areas, where trees from cooler climates suffered greater than 2× more herbivory than trees from warmer areas. Plant genotype was a significant factor for selection, with the most heavily browsed genotype having greater than 10× more herbivory than the least browsed. Broad‐sense heritability of porcupine tree selection was H2B = 0.27 among genotypes, indicating a genetic component to tree defenses against porcupine herbivory that can be predicted by source population climate. Our results have important implications for future mammalian herbivore populations, should climate change render local tree genotypes maladaptive. We recommend assisted migration efforts plant stock from areas up to 3°C warmer and climatically similar areas to maintain productivity and mammalian herbivore browsing.

Effects of Photoperiod Treatments on Stock Plants and Cutting Rooting of Winecups

Production of attractive and water-efficient plants native to the plains and prairies of central North America can sometimes be limited because of problems associated with successful rooting of vegetative cuttings. Winecups (Callirhoe involucrata) is an attractive native plant, valued for its long period of bloom, drought tolerance, and winterhardiness, but can be difficult to propagate from seeds and vegetative cuttings. Seed dormancy issues can result in unreliable germination and seedling variations, which reduces crop uniformity. Although propagation from rooted cuttings maintains crop uniformity, cuttings often fail to root or root poorly. Manipulating the growing conditions of stock plants to suppress reproductive growth may improve rooting success of vegetative cuttings. Based on research conducted earlier with other ornamental perennials and programmed photoperiods, winecups plants were grown under three programmed photoperiods to determine if a particular photoperiod could be used to suppress reproductive growth and promote vegetative growth. The study consisted of three experiments, all conducted in similar fashion but at different times during the year. Results indicate that plants grown under 10-hour and 8-hour photoperiods remained vegetative longer when compared with plants grown under 12-hour photoperiod. Vegetative cuttings harvested from plants grown under 8-hour photoperiod had higher percent rooting when compared with vegetative cuttings harvested from plants grown under 10-hour and 12-hour photoperiods. Based on the findings from this research, plant propagators may be able to increase production of winecups by growing stock plants under 8-hour photoperiod.

Testing source elevation versus genotype as predictors of sugar pine performance in a post‐fire restoration planting

AbstractClimate change is motivating a reassessment of how seeds are selected for reforestation, as rapid environmental change can lead to local maladaptation in trees. Genetic association studies and past seed source climate both have the potential to help identify appropriate planting stock, but these techniques have not been compared and tested as part of an operational planting program. In this study, we combined an analysis of single nucleotide polymorphisms (SNPs) associated with environmental gradients in sugar pine (Pinus lambertiana) with an analysis of post‐fire seedling survival and growth in a restoration experiment. Our genotype–environment association (GEA) tests of 92 individuals from varying climates within CA revealed 829 SNPs (out of 300,604) with significant association with climate gradients, especially April snowpack. Of these, 323 either had annotations that suggested potential functional importance or were identified by two different methods. We then built Bayesian models of survival and growth for all seedlings in a separate post‐fire planting experiment, to test the relative predictive ability of source elevation (a common proxy for source climate) versus the proportion of seedling alleles expected to be locally advantageous based on GEA. Across three sites within the King Fire scar in Eldorado National Forest in 2017, 2018, and 2019, 1774 seedlings were planted. Of these, 206 had enough green needles in 2020 to allow sample collection, and 161 were successfully genotyped. We found that source elevation was generally better at predicting seedling performance than genotype indices, perhaps because of the limited scope of the association analysis. Seed sources from 500 to 1800 ft (152.4–548.6 m) lower in elevation, and one seed zone further south generally performed as well or better than local seed sources. This result, and those of similar previous studies, suggest that “climate matching” using past climate information for existing seed sourcing units is a reasonable starting point for finding seedlings suited to already‐altered planting site climate conditions. However, further tests with more extensive genomic and performance data may improve the utility of genotype information for seed selection.

Fine-scale monitoring of catkins reveals an association between catkin concentration and plant community characteristics and microclimate

Catkins, as a significant source of plant-caused pollution, disrupts daily human activities and industrial processes. Despite their impact, catkins have not been included in official environmental quality monitoring indicators, leading to a deficiency in scientifically rigorous collection and monitoring methodologies, as well as a lack of ecological prevention and management strategies. In this study, we introduced a fine-scale monitoring approach for catkins. Qualitative and quantitative relationships between catkin concentrations, plant community characteristics and microclimate factors were elucidated by analyzing on-site catkin concentration data from 33 representative plant communities in Beijing. Furthermore, we summarized the ecological strategies for the prevention and management of these catkins. The results indicated that (1) TS (three-dimensional green volume of trees in the catkin source layer), SB (three-dimensional green volume of shrubs in the catkin barrier layer), GB (three-dimensional green volume of ground cover plants in the catkin barrier layer), T (three-dimensional green volume of trees in the whole plant community), W (three-dimensional green volume of the whole plant community), species diversity, and relative air humidity were key plant community characteristics and microclimate factors influencing catkin concentration. Among these factors, TS, T, W, and relative air humidity showed a significant positive correlation with catkin concentration, while SB, GB, and species diversity exhibited a significant negative correlation with catkin concentration. (2) All seven key factors exhibited nonlinear relationships with catkin concentration. (3) TS served as the primary deciding factor for catkin concentration within the plant community. When TS > 744.0755 m3, the secondary decision factor for catkin concentration was GB. Otherwise, the determinants were SB and species diversity. The results showed that enhancing tree species diversity, enhancing the three-dimensional green volume of shrubs and ground cover plants, and increasing air humidity were practical means to facilitate the sedimentation of catkins. The measures used to obstruct catkins vary depending on the TS. When catkin source plants are abundant within a plant community, it is advisable to prioritize increasing ground cover plants. Conversely, when fewer sources of such plants exist, emphasis can be placed on augmenting mid-layer shrubs and diversifying plant species. These findings provide a scientific foundation for the planting design and stock optimization of communities containing catkin source plants.

Physiological Age of Stock Plants Determines Phytohormonal Changes in Leafy Cuttings of Prunus subhirtella 'Autumnalis'

AbstractThe aim of this study was to investigate adventitious root formation in cuttings obtained from physiologically different old stock material. The ornamental cherry Prunus subhirtella ´Autumnalis´ was used for the experiment. We examined three stock plants, namely a physiologically mature stock plant (about 60 years old) and physiologically juvenile plants (21 years old), which were previously propagated by cuttings, semi-mature stock material and in vitro juvenile stock material. We also investigated the role of phytohormones in the induction phase of adventitious root (AR) formation depending on the physiological age of the stock plant and the time after cutting. High performance liquid chromatography coupled with mass spectrometry (HPLC–MS/MS) was used to identify and quantify the phytohormones. The difference in rooting and quality of the developed AR is observed between semi-mature stock and mature stock material. Cuttings from semi-mature plants rooted in 95.00% of cases, while cuttings from mature stock plants only rooted in 68.33%. The high concentration of strigolactones and jasmonic acid (JA) immediately after severance had an inhibitory effect on the development of adventitious roots, especially in cuttings of mature origin. The development of AR is positively influenced by the increase in indole-3-acetic acid (IAA) 4 h after cutting from the stock plant. Our results show that the formation of adventitious root formation depends on the concentration and ratio between different phytohormones.

Effects of the comprehensive elimination of Spartina alterniflora along China's coast on blue carbon and scenario prediction after ecological restoration

Salt marshes cover the largest area among the three types of traditional blue carbon ecosystems in China's coastal zone, with the introduced smooth cordgrass (Spartina alterniflora Loisel.) being dominant in these marshes. The effects of eradicating S. alterniflora nationwide and the subsequent ecological restoration on blue carbon are unclear. This paper evaluates the variation in blue carbon during the national S. alterniflora eradication campaign, which involves mechanical tillage from 2022 to 2025, and proposes three scenarios for blue carbon changes after native vegetation is reestablished by 2050. The results show that, in 2025, plant carbon stock and soil carbon stock will decrease by 1.38 Tg C and 1.21 Tg C, respectively, in the areas where S. alterniflora has been removed and managed. Although blue carbon is reduced in coastal wetlands in 2025, carbon stock is expected to increase in restored native vegetated wetlands by 2050. S. alterniflora is resilient and competitive, posing a high risk in secondary invasion. Scenario Ⅰ suggests that S. alterniflora marshes could almost recover to their original state from 2022, with 7.70 Tg C stored in plant and soil carbon stocks. Scenario Ⅱ involves native vegetated wetlands coexisting with invasive S. alterniflora marshlands, with a total carbon stock estimated at 7.15 Tg C, reflecting a decrease of 0.39 Tg C in soil carbon stock and by 0.16 Tg C in plant carbon stock. In Scenario Ⅲ, mudflats dominant and native vegetated habitats are reestablished only in suitable sites, with the total carbon stock estimated at 5.63 Tg C, a 26.9% decrease compared to 2022 levels. While eradicating invasive S. alterniflora and restoring native vegetation in China's coast enhance the ecosystem services, it reduces blue carbon stocks. Therefore, developing additional strategies to increase carbon storage in coastal wetlands is necessary.

Assisted migration outcomes for oak species and seed sources in southern Ontario, Canada

IntroductionForest assisted migration has been proposed as a means to align tree populations with shifting climate habitats under climate change. Here we report on the growth and survival of oak species and seed sources at five assisted migration trials in southern Ontario – an important transition zone between boreal and temperate ecosystems.MethodsEach trial featured one or more oak species – including red oak (Quercus rubra), white oak (Q. alba), burr oak (Q. macrocarpa), and swamp white oak (Q. bicolor) – and seed sources from Ontario, Pennsylvania, and/or Tennessee. The trials were measured for survival and height at between 7 and 13 years after planting.ResultsFor several trials and species, southern seed sources performed nearly as well as local sources. However, southern seed sources of burr oak performed significantly worse than local sources at 2 trials in eastern Ontario. These outcomes may have been influenced by reduced quality of southern seed source planting stock at these trials.DiscussionOur findings generally support previous work that suggests northward movements of seed sources of several hundred kilometers may be safe for assisted migration efforts involving broadleaf tree species. Notably, the trial sites were located at the northern range limits of two oak species in this study (Q. alba and Q. bicolor), suggesting the potential for modest range expansions in this boreal-temperate transition zone. These findings help forest managers to better understand potential assisted migration outcomes under climate change.

Understanding the dissemination of viruses and viroids identified through virome analysis of major grapevine rootstocks and RPA-based detection of prevalent grapevine virus B

Grapevine stocks are generally vegetatively propagated for the commercial cultivation. The propagation is predominantly done on rootstocks with >90 % of plant stocks propagated on Dogridge rootstock alone in India. Three additional rootstocks i.e. Paulsen, SO4 and Ramsey are also used for grapevine propagation on a limited scale. However, no information is available on the health status of these rootstocks being used by nurserymen and growers. Therefore, these rootstocks were collected from nurseries of five different locations and subjected to high-throughput sequencing (HTS) to determine the spectrum of viruses and viroids. The de novo assembly of unaligned reads revealed the presence of genome sequences of nine viruses viz. grapevine rupestris stem pitting-associated virus (GRSPaV), grapevine leafroll-associated virus 3 (GLRaV-3), grapevine leafroll-associated virus 4 (GLRaV-4), grapevine virus A (GVA), grapevine virus B (GVB), grapevine virus D (GVD), grapevine virus F (GVF), grapevine virus L (GVL), grapevine fleck virus (GFkV) and five viroids viz. hopstunt viroid (HSVd), grapevine yellow speckle viroid 1 and 2 (GYSVd-1 and GYSVd-2), Australian grapevine viroid (AGVd) and grapevine latent viroid (GLVd). The identified viruses and viroids were further confirmed through RT-PCR and Sanger sequencing. Indexing for the presence of these graft-transmissible pathogens in 43 rootstocks and 23 scion samples collected through field surveys indicated that infected rootstocks are the probable source for dissemination of these viruses and viroids in grapevine scions. As GVB was the most prevalent virus in all the rootstocks and scions as observed in RT-PCR testing, a simplified crude sap-based recombinase polymerase amplification (RPA) assay was optimized for its rapid detection. The present study highlights that grapevine rootstocks are reservoir of viruses and viroids and source for their dissemination in grapevine vineyards. Findings of the study including the optimized simplified cost-effective isothermal nucleic acid-based detection technique for GVB will be highly useful for production of certified clean rootstocks of grapevine in India.

Major overlap in plant and soil organic carbon hotspots across Africa

Terrestrial plant and soil organic carbon stocks are critical for regulating climate change, enhancing soil fertility, and supporting biodiversity. While a global-scale decoupling between plant and soil organic carbon has been documented, the hotspots and interconnections between these two carbon compartments across Africa, the second-largest continent on the planet, have been significantly overlooked. Here, we have compiled over 10,000 existing soil organic carbon observations to generate a high-resolution map, illustrating the distribution pattern of soil organic carbon in Africa. We then showed that above- and below-ground plant carbon are significantly and positively correlated with soil organic carbon across Africa. Both soil and plant carbon compartments shared major hotspots in the tropical regions. Our study provides critical insights into the spatial distribution of carbon hotspots across Africa, essential for soil conservation and safeguarding terrestrial carbon stocks amidst the challenges of climate change.

Study of the Procurement of Landscape Plant Nurseries in Sukamantri Village Tamansari Sub-district Bogor Regency

Abstract Nurserymen play an important role in the landscape industry by producing and providing plants according to the required specifications. Sukamantri Village is one of the centers of landscape plant production and sales in Bogor Regency. The main problem faced by the nursery is the fluctuating demand for landscape plants, which can cause a shortage or excess of plant stock. This research was conducted in Sukamantri Village, Tamansari Sub-district, Bogor Regency, from November 2022 to February 2023. This study aims to obtain information on the variety of plants in the nurseries and analyze the problems in order to obtain recommendations for the development and sustainability of the nursery. Data obtained through surveys, interviews, and secondary data. They were analyzed quantitatively and qualitatively using the SWOT approach regarding internal and external factors in the procurement of landscape plants. The results show the variety of plants includes indoor and outdoor ornamental plants, herbal plants, and fruit plant seedlings. The problem faced is the decline in domestic and foreign sales. Some of the recommended strategies include developing human resource skills, improving production technology, better planning production, promoting on social media, and expanding the market by strengthening networks.

Air layering in Caryocar brasiliense: effect of substrate

The commercial propagation of Caryocar brasiliense Cambess is hindered by several factors, including seed dormancy and low cutting survival rates. Air layering studies are needed to overcome these limitations. Previous studies have reported the influence of substrates on the rooting of air layers for different species. Therefore, the objective of this study was to evaluate the influence of substrates on air layering of Caryocar Brasiliense. An experiment was conducted with eight stock plants located at Embrapa Cerrados, Distrito Federal, Brazil, using different substrates, including Bioplant®, coconut fiber, a mixture of Bioplant® and coconut fiber in 3:1, 1:1, 1:3 proportions, rice husk biochar, vermiculite, sawdust, soil, and sand. Each treatment was replicated four times. After five months, the survival rate, callus formation, rooting percentage, root length, fresh and dry root mass, and rooting vigor were evaluated. The survival and callus formation rates in all substrates were above 95%. Bioplant® substrate provided the highest rooting percentage (77%), fresh and dry root mass (17.08g and 3.16g, respectively), while soil provided the lowest rooting percentage (17%) and fresh and dry root mass (0.1g and 0.02g, respectively). The average root length was 6.63 cm in the 1:1 mixture. Based on the evaluated characteristics, Bioplant® is the most suitable substrate for the propagation of C. brasiliense stock plants by air layering. The results suggest that air layering is a viable alternative to the vegetative propagation of Caryocar brasiliense stock plants.

Impact of Various IBA Concentrations on Rooting in Apical Shoot Cutting and Stem Cuttings of Callistemon lanceolatus (Sm.) Sweet in Polytunnel Conditions

The study was undertaken to identify the optimal concentration of IBA and type of cuttings suitable for propagation of Callistemon lanceolatus and it was conducted at the Vanavarayar Institute of Agriculture, Pollachi, Coimbatore, India from December 2022 to September 2023. The experiment addressed the challenges of seed propagation, such as their seed capsules need to be activated by fire and the unpredictable nature of seed germination, which results in high progeny diversity due to genetic recombination. The investigation focused on apical and stem cuttings subjected to fifteen different treatments with three replications each; the Tukey test was used for statistical analysis; the cuttings were treated with various concentrations of Indole-3-butyric acid (IBA) and placed under polytunnel conditions; observations were made after 45 days, measuring sprouting percentage, rooting percentage, mean number of leaves, shoot length, mean number of roots, and root length per cutting. In light of these issues, the study explored clonal propagation as an alternative for mass multiplication of elite trees. The results of the study depicted that the maximum rooting percentage and root length were observed in T6 (73.28±8.87%) and (12.54±0.00cm) due to the exogenous application of auxin. On the whole, the result of this investigation suggest that apical shoot cuttings with IBA at 6000ppm can be made to induce maximum rooting and to produce high quality planting stock material for clonal propagation in Callistemon lanceolatus.

Grassland association stock of plants the examination of the regeneration of a construction

Due to the drastic change in using the nature like grassland association (one-sided overgrazing – one mowing per a year), by the third year of the experiment in every area, where overgrazing stopped, independently on second sowing and nutrient resupply, Borhidi degradation degree decreased. In the areas where overgrazing with large animal density (sheep) continued, degradation degree was 3.4–5.0 by the third year of the experiment, and Hordeum murinum, which causes animal healthy problems, appeared massively.

Effects of Photoperiod Treatments on Stock Plants and Cutting Rooting of Three Cultivars of Ornamental Perennials

Many species of herbaceous perennials now have numerous cultivars, with growth habits and flower colors unique to each cultivar. Vegetative propagation is required so that resulting plants are genetically identical to the parent plant. Although many cultivars are selected for precocious and vigorous flowering, it is often difficult to collect adequate vegetative cuttings from such cultivars for commercial production because juvenile (vegetative) growth is preferred for high-quality cuttings. Cuttings that are reproductive (with flower buds or flowers) can have reduced or delayed rooting and increased occurrences of fungal pathogens (especially Botrytis species), resulting in lack of crop uniformity. We sought to answer the question, can growing stock plants of herbaceous perennials under defined photoperiods extend the length of the vegetative period and enhance the rooting of cuttings harvested from these stock plants? In this study, stock plants of ‘P009S’ twinspur (Diascia integerrima), ‘Furman's Red’ sage (Salvia greggii), and ‘Wild Thing’ sage (Salvia greggii) were grown under ambient, 12-hour light, 10-hour light, and 8-hour light to determine if a particular photoperiod could be used to suppress reproductive growth by promoting vegetative growth, thereby enhancing cutting rooting success. Effects of photoperiod treatments varied among the plant cultivars studied. Plants grown under 8-hour photoperiod had longer duration of vegetative growth, smaller growth rates, and lower dry weights when compared with plants grown under 12-hour or 10-hour photoperiod. Plants grown under 12-hour photoperiod had shorter duration of vegetative growth, larger growth rates, and higher dry weights when compared with plants grown under 10-hour and 8-hour photoperiods. The probability of rooting of cuttings harvested from stock plants of ‘P009S’ twinspur, ‘Furman’s Red’ sage, and ‘Wild Thing’ sage grown under 12-hour and 10-hour photoperiods was greater when compared with cuttings harvested from stock plants grown under 8 h photoperiod.

The Application Timing of a Cytokinin B-Mo-based Product Affects the Characteristics of Rooted Cuttings and Nonstructural Carbohydrates of Coleus (Plectranthus scutellarioides cv. Wild Lime) during Adventitious Root Development

A large group of horticulture species are propagated vegetatively through shoot-tip cuttings harvested from stock plants and planted to form adventitious roots. Adventitious rooting leads to establishing a carbohydrate sink in the region of root regeneration that is highly dependent on energy and carbon skeletons. We hypothesized that the timing of exogenous applications of cytokinin (CK) and boron (B)–molybdenum (Mo)-based products during adventitious root development can affect the flow of sugars from leaves to sinks, carbon allocation to the adventitious roots, and the quality of rooted cuttings. During this project, we aimed to determine if the application time of a CK/B-Mo-based product during the adventitious root development of unrooted cuttings would impact the source-to-sink relationship and, hence, affect plug growth and quality. A sink-strengthening commercial product based on cytokinin, B, and Mo was applied at four plug development stages plus a negative control as follows: T1, plants without product (control); T2, sticking stage (starting 24 hours after the sticking); T3, callus formation stage; T4, root development stage; and T5, toning stage. The root and shoot lengths and dry matter, number of leaves, leaf chlorophyll content, root-to-shoot ratio (based on dry matter), and nonstructural carbohydrate contents were measured. The timing of the application of the product impacted the root development, quality of the cuttings, and nonstructural carbohydrate content. Product application during the adventitious root dedifferentiation and induction phases (T2) resulted in the shortest root and shoot lengths, lowest dry matter accumulation, lowest nonstructural carbohydrate contents, and some phytotoxicity. Application during the initiation phase (T3) resulted in greater root length, total dry matter, and total soluble sugar contents compared with the control. Application during the expression phase (T4) resulted in the largest root length and mass and the highest sucrose contents. Applying the product when the roots had grown and reached all the edges of the growing media (T5) did not have any benefits compared with the control. This study provides new insights into the application timing of exogenous CKs, B, and Mo to generate a well-toned rooted coleus cutting and potential explanations in relation to nonstructural carbohydrate metabolism.

Sacred forests in the Western Highlands Cameroon: What benefits for local population and nature?

The sacred forests of the Western Highlands Cameroon are, like other forests, a reserve of plants and genes, both known and unknown. They are privileged places for communication with ancestors. They provide significant environmental and socio-economic benefits; despite the pressure they are increasingly coming under. The aim of this study is to categorise the different uses of the sacred forests of Bafou, Baleveng and Bamendou, and then to assess the carbon stock of the woody plants in these forests. A survey form was used to record the various benefits derived by local people from the sacred forests. Individuals were counted in 30 m x 100 m plots. All individuals with a diameter ≥5 cm at 1.30 m above ground were considered. Carbon sequestered by forests was estimated using the non-destructive method. The study shows that the traditional laws protecting these forests are increasingly being violated by local people. These forests are cultural properties for the village and provide the local population with a variety of products. The most frequently cited uses are firewood, food products, medicinal plants and sacrifices. A total of 54 species, 47 genera and 29 families have been identified. Of these species, around 40.35% are used in one way or another by local people. The values of carbon sequestered by these forests vary from one forest to another and according to the type of equation chosen. The Bamendou sacred forest recorded the highest value, 443.9 t C /ha and 287.79 t C /ha respectively, using the equations of Djomo et al. (2010) and Fayolle (2013). This work presents the benefits of sacred forests for local populations. Management strategies for these forests should be strengthened by the State to ensure more sustainable conservation of this rich heritage.

Biochemical mechanisms preventing wilting under grafting: a case study on pumpkin rootstock grafting to wax gourd.

Wax gourd wilt is a devastating fungal disease caused by a specialized form of Fusarium oxysporum Schl. f. sp. benincasae (FOB), which severely restricts the development of the wax gourd industry. Resistant rootstock pumpkin grafting is often used to prevent and control wax gourd wilt. The "Haizhan 1" pumpkin has the characteristic of high resistance to wilt, but the mechanism through which grafted pumpkin rootstock plants acquire resistance to wax gourd wilt is still poorly understood. In this study, grafted wax gourd (GW) and self-grafted wax gourd (SW) were cultured at three concentrations [2.8 × 106 Colony Forming Units (CFU)·g-1, 8.0 × 105 CFU·g-1, and 4.0 × 105 CFU·g-1, expressed by H, M, and L]. Three culture times (6 dpi, 10 dpi, and 13 dpi) were used to observe the incidence of wilt disease in the wax gourd and the number of F. oxysporum spores in different parts of the soil and plants. Moreover, the physiological indices of the roots of plants at 5 dpi, 9 dpi, and 12 dpi in soil supplemented with M (8.0 × 105 CFU·g-1) were determined. No wilt symptoms in GW. Wilt symptoms in SW were exacerbated by the amount of FOB in the inoculated soil and culture time. At any culture time, the amount of FOB in the GW soil under the three treatments was greater than that in the roots. However, for the SW treatments, at 10 dpi and 13 dpi, the amount of FOB in the soil was lower than that in the roots. The total phenol (TP) and lignin (LIG) contents and polyphenol oxidase (PPO) and chitinase (CHI) activities were significantly increased in the GWM roots. The activities of phenylalanine ammonia lyase (PAL) and peroxidase (POD) initially decreased but then increased in the GWM roots. When the TP content decreased significantly, the LIG content and PAL and CHI activities increased initially but then decreased, whereas the PPO and POD activities did not change significantly in the SWM roots. The results indicated that the roots of the "Haizhan 1" pumpkin stock plants initiated a self-defense response after being infected with FOB, and the activities of PPO, POD, PAL, and CHI increased, and additional LIG and TP accumulated, which could effectively prevent FOB infection.

Substrate and fertirigation for acclimatization of Fragaria x ananassa vitroplants

The in vitro plant tissue culture technique is based on the isolation of organs, tissuesor cells, which, by establishing them in aseptic conditions, and culture medium ofdefined composition and incubation, induce physiological responses, cell divisionand morphogenesis. An application of the tissue culture technique ismicropropagation that consists of stages: 0) selection of the stock plant; I) surfacedisinfection of plant material to establish it in culture medium; II) multiplication ofpropagules; III) rooting of shoots, growth of seedlings and preparation fortransplanting to substrate; IV) transfer of micropropagated plants to substrate foracclimatization in greenhouse. The objective was to evaluate the acclimatization ofmicropropagated strawberry Fragaria x ananassa Duch. plants that were establishedin substrates containing perlite and peat alone or combined in different proportions,and that were fertigated with different dilutions of nutrient solution. After 34 days ofacclimatization from a total of 210 plants evaluated in the various substrate andfertigation conditions, all were acclimatized, and the plants that reached the biggestsize were those established in substrates with 50 to 100% peat and were fertigatedwith any dilutions of nutrient solution.

Synergistic interplay between melatonin and hydrogen sulfide enhances cadmium-induced oxidative stress resistance in stock (Matthiola incana L.)

ABSTRACT Ornamental crops particularly cut flowers are considered sensitive to heavy metals (HMs) induced oxidative stress condition. Melatonin (MLT) is a versatile phytohormone with the ability to mitigate abiotic stresses induced oxidative stress in plants. Similarly, signaling molecules such as hydrogen sulfide (H2S) have emerged as potential options for resolving HMs related problems in plants. The mechanisms underlying the combined application of MLT and H2S are not yet explored. Therefore, we evaluated the ability of individual and combined applications of MLT (100 μM) and H2S in the form of sodium hydrosulfide (NaHS), a donor of H2S, (1.5 mM) to alleviate cadmium (Cd) stress (50 mg L−1) in stock (Matthiola incana L.) plants by measuring various morpho-physiological and biochemical characteristics. The results depicted that Cd-stress inhibited growth, photosynthesis and induced Cd-associated oxidative stress as depicted by excessive ROS accumulation. Combined application of MLT and H2S efficiently recovered all these attributes. Furthermore, Cd stress-induced oxidative stress markers including electrolyte leakage, malondialdehyde, and hydrogen peroxide are partially reversed in Cd-stressed plants by MLT and H2S application. This might be attributed to MLT or H2S induced antioxidant plant defense activities, which effectively reduce the severity of oxidative stress indicators. Overall, MLT and H2S supplementation, favorably regulated Cd tolerance in stock; yet, the combined use had a greater effect on Cd tolerance than the independent application.

Stem Cutting Propagation and Micropropagation of Northern Bayberry

Northern bayberry [Morella (formerly Myrica) pensylvanica] is an attractive, adaptable, semievergreen, northeastern North American native shrub that is sought for landscaping but difficult to propagate clonally. The impact of timing (June, July, or August) and concentration of indole-3-butyric acid [IBA (0, 2000, 4000 or 8000 ppm)] on propagation by stem cuttings was evaluated for genotypes of northern bayberry including the female cultivars Bobzam (Bobbee™) and UConn Compact and an unnamed male. Medium formulation and cytokinin type were evaluated for micropropagation of ‘Bobzam’ and ‘UConn Compact’. Stem cuttings of ‘Bobzam’ and ‘UConn Compact’ rooted poorly (at ≤55% and ≤20%, respectively) at all timings and concentrations of IBA; however, rooting success of ≥85% was achieved for the unnamed male genotype when cuttings were taken in June. Micropropagation of ‘Bobzam’ was successful using Woody Plant medium with 4 mg·L−1 zeatin and explants taken from shoots that had expanded 12 to 18 cm on containerized stock plants. Initiated explants of ‘Bobzam’ required eight subcultures before they began to produce shoots consistently at a 2× multiplication rate and eventually reached a 3× multiplication rate. Micropropagation attempts using Murashige and Skoog medium, the cytokinins 6-benzylaminopurine, meta-topolin, and thidiazuron, or the cultivar ‘UConn Compact’ were unsuccessful. Microshoots of ‘Bobzam’ rooted at ≥80% either by in vitro prerooting or ex vitro rooting directly in trays. Rooted microcuttings easily acclimated to greenhouse conditions and grew rapidly when potted to 1.04-L containers and then into 5.68-L containers. The micropropagation protocol developed for ‘Bobzam’ can be used by propagators to expand production of this popular female cultivar.