Leaf morphology, optical characteristics and phytochemical traits of butterhead lettuce affected by increasing the far-red photon flux.

Light and its spectral characteristics are crucial for plant growth and development. The far-red photon flux mediates many plant processes through the action of phytochrome and also accelerates the photosynthetic electron transfer rate. In this study, we assessed the effects of far-red addition on butterhead lettuce morphology, light use efficiency, optical properties, and phytochemical characteristics.

Salt Stress Induced Changes in Photosynthesis and Metabolic Profiles of One Tolerant ('Bonica') and One Sensitive ('Black Beauty') Eggplant Cultivars ( L.).

The impact of salinity on the physiological and biochemical parameters of tolerant (‘Bonica’) and susceptible (‘Black Beauty’) eggplant varieties (Solanum melongena L.) was determined. The results revealed that the increase in salinity contributes to a significant decline in net photosynthesis (An) in both varieties; however, at the highest salt concentration (160 mM NaCl), the decrease in photorespiration (Rl) was less pronounced in the tolerant cultivar ‘Bonica’.

Obtaining Salt Stress-Tolerant Eggplant Somaclonal Variants from In Vitro Selection.

An efficient regeneration protocol was applied to regenerate shoots on salt stress-tolerant calli lines of aubergine (). These NaCl-tolerant cell lines were obtained by two different methods. On the one hand, the developed callus tissue was transferred to a medium with a continuous salt content of 40, 80, 120, or 160 mM NaCl.

In-Depth Observation on the Microbial and Fungal Community Structure of Four Contrasting Tomato Cultivation Systems in Soil Based and Soilless Culture Systems.

As soil and soilless culture systems are highly dynamic environments, the structure of rhizosphere microbial communities is consistently adapting. There is a knowledge gap between the microbial community structure of soil based and soilless culture systems and thus we aimed at surveying their impact on diversity and composition of bacterial communities across a 10-month period in a tomato cultivation system. We compared community metrics between an soil based culture system fertilized with malt sprouts and blood meal, known for its slow and high mineralization rate, respectively and a soilless culture system fertilized with fish effluent or supplemented with an liquid organic fertilizer.

Phenotypic Variation of Isolates Is Influenced by Spectral Light Quality.

, a fungal pathogen that causes gray mold, displays a high degree of phenotypic diversity. Light emitting diodes (LEDs) with specific light spectrum are increasingly used as lighting resource for plant greenhouse production. The chosen light spectrum can also have an effect on the pathogens in this production system.

Timing of light quality affects susceptibility to Botrytis cinerea in strawberry leaves.

Light plays an essential role in the outcome of plant-pathogen interactions. In this study, the effect of pre- and post-inoculation light quality on Botrytis cinerea disease development in strawberry leaves was investigated. Circadian variations in leaf susceptibility to Botrytis cinerea were tested by inoculating at 5 h, 12 h, or 16 h after the start of photoperiod.

Red Light Is Effective in Reducing Nitrate Concentration in Rocket by Increasing Nitrate Reductase Activity, and Contributes to Increased Total Glucosinolates Content.

Rocket cultivation is increasing to supply the expanding ready-to-eat market because of its unique taste, but crops are often over fertilized to avoid nitrogen deficiencies. This leads to nitrate accumulation in leaves, and the products of their degradation (nitrites and nitrosamines) have been related to several health problems. Nitrate concentrations in rocket and other leafy vegetables are subject to limits by the EU legislation, yet rocket holds a great nutritional value.

Cold Acclimation and Deacclimation of Two Garden Rose Cultivars Under Controlled Daylength and Temperature.

Low temperature stress is an important abiotic stress for garden roses in northern regions. Two garden rose cultivars ('Dagmar Hastrup' and 'Chandos Beauty') were selected to study the role of dehydrin and of carbohydrate metabolism during cold acclimation and deacclimation under the controlled daylength and temperature. The presence of bud dormancy was also observed as this could prevent budburst during warm spells.

The jasmonic acid pathway, rather than abscisic acid, may partly explain contrasting stomatal responses in two strawberry cultivars under osmotic stress.

Drought is a major threat in agriculture and horticulture, including commercial strawberry production. Here, we compare hormonal regulation of a first-line drought stress response, namely stomatal closure, in two Fragaria x ananassa cultivars, known to differ in their drought stress phenotype. We show that the observed difference in xylem abscisic acid accumulation cannot explain the different stomatal responses under osmotic stress.

Spectral quality of monochromatic LED affects photosynthetic acclimation to high-intensity sunlight of Chrysanthemum and Spathiphyllum.

Vertical farming using light-emitting diode offers potential for the early production phase (few weeks) of young ornamental plants. However, once transferred to the greenhouse, the photosynthetic acclimation of these young plants might depend on this initial light regime. To obtain insight about this acclimatization, Chrysanthemum (sun species) and Spathiphyllum (shade species) were preconditioned in growth chambers for 4 weeks under four light qualities: blue (B), red (R), red/blue (RB, 60% R) and white (W) at 100 μmol m s .

Physiological responses and aquaporin expression upon drought and osmotic stress in a conservative vs prodigal Fragaria x ananassa cultivar.

In order to improve the understanding of plant water relations under drought stress, the water use behavior of two Fragaria x ananassa Duch. cultivars, contrasting in their drought stress phenotype, is identified. Under drought, stomatal closure is gradual in Figaro.

Tomato plants rather than fertilizers drive microbial community structure in horticultural growing media.

Synthetic fertilizer production is associated with a high environmental footprint, as compounds typically dissolve rapidly leaching emissions to the atmosphere or surface waters. We tested two recovered nutrients with slower release patterns, as promising alternatives for synthetic fertilizers: struvite and a commercially available organic fertilizer. Using these fertilizers as nitrogen source, we conducted a rhizotron experiment to test their effect on plant performance and nutrient recovery in juvenile tomato plants.

Adventitious rooting of Chrysanthemum is stimulated by a low red:far-red ratio.

Adventitious rooting, a critical process in the vegetative propagation of many ornamentals, can be affected by both light intensity and light quality. We investigated the use of spectral light quality to improve adventitious rooting of Chrysanthemum morifolium cuttings by applying different combinations of blue, red and far-red light. Additionally, unrooted cuttings were treated before planting with two auxin transport inhibitors (TIBA and NPA) to study the effect of light quality on auxin biosynthesis and/or transport.

Light quality affects light harvesting and carbon sequestration during the diel cycle of crassulacean acid metabolism in Phalaenopsis.

Crassulacean acid metabolism (CAM) is a specialized photosynthetic pathway present in a variety of genera including many epiphytic orchids. CAM is under circadian control and can be subdivided into four discrete phases during a diel cycle. Inherent to this specific mode of metabolism, carbohydrate availability is a limiting factor for nocturnal CO uptake and biomass production.

Seasonal changes in cold hardiness and carbohydrate metabolism in four garden rose cultivars.

We studied metabolic adaptations to cold stress in roses and identified genes in the carbohydrate pathway during acclimation and deacclimation. A field experiment with four rose cultivars belonging to different USDA plant hardiness zones was set up in Melle, Belgium (51° 0' N, 3° 48' E). The more cold-hardy cultivars ('Dagmar Hastrup' and 'John Cabot') reached their lowest LT value in December, indicating a rapid acclimation after the first occurrence of frost.

Prediction of Lime Tolerance in Based on Herbarium Specimen and Geochemical Data.

Rhododendrons are typically known to be calcifuges that cannot grow well in lime soils. Data on lime tolerance of different taxa in are scarce. Habitats of naturally distributed specimens of genus were compiled as Chinese text-based locations from the Chinese Virtual Herbarium.

Identification and substrate prediction of new aquaporins and expression in different tissues and during strawberry fruit development.

The newly identified aquaporin coding sequences presented here pave the way for further insights into the plant-water relations in the commercial strawberry (). Aquaporins are water channel proteins that allow water to cross (intra)cellular membranes. In , few of them have been identified hitherto, hampering the exploration of the water transport regulation at cellular level.

The Variable Effect of Polyploidization on the Phenotype in .

To induce new variation within the genus, chromosome doubling was performed in , and , three important species within this genus of mainly evergreen woody ornamental species. Obtained tetraploids and diploid controls were analyzed for rooting capacity, leaf and flower characteristics, and plant architecture using image analysis and cold tolerance. In the present study, a breeders' collection of 23 accessions was characterized cytogenetically and described morphologically.

Long-Term Effects of Red- and Blue-Light Emitting Diodes on Leaf Anatomy and Photosynthetic Efficiency of Three Ornamental Pot Plants.

Light quality critically affects plant development and growth. Development of light-emitting diodes (LEDs) enables the use of narrow band red and/or blue wavelengths as supplementary lighting in ornamental production. Yet, long periods under these wavelengths will affect leaf morphology and physiology.

Morpho-physiological responses to dehydration stress of perennial ryegrass and tall fescue genotypes.

Worldwide drought stress is the most important restriction factor on food and fodder productivity. In this study, morpho-physiological adaptations to dehydration stress were investigated in two tall fescue (Festuca arundinacea Schreb.) genotypes (Fa13 and Fa19 with a high and low sheep grazing preference respectively) and Lolium perenne L.

Chrysanthemum morphology, photosynthetic efficiency and antioxidant capacity are differentially modified by light quality.

The effect of light quality on leaf morphology, photosynthetic efficiency and antioxidant capacity of leaves that fully developed under a specific spectrum was investigated in Chrysanthemum cv. Four light treatments were applied at 100μmolms and a photoperiod of 14h using light-emitting diodes, which were 100% red (R), 100% blue (B), 75% red with 25% blue (RB) and white (W), respectively. Intraspecific variation was investigated by studying the response of eight cultivars.

Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint.

Suboptimal Light Conditions Influence Source-Sink Metabolism during Flowering.

Reliance on carbohydrates during flower forcing was investigated in one early and one late flowering cultivar of azalea (Rhododendron simsii hybrids). Carbohydrate accumulation, invertase activity, and expression of a purported sucrose synthase gene (RsSUS) was monitored during flower forcing under suboptimal (natural) and optimal (supplemental light) light conditions, after a cold treatment (7°C + dark) to break flower bud dormancy. Post-production sucrose metabolism and flowering quality was also assessed.

Pesticide knowledge and practice among horticultural workers in the Lâm Đồng region, Vietnam: A case study of chrysanthemum and strawberries.

Background: In Vietnam, large amounts of pesticides are being used in agriculture. Next to benefits for agriculture, pesticides impose a huge threat to the environment when they are used in the wrong way. The objective of this work was to determine the level of knowledge and awareness of the smallholder farmers towards the use of pesticides in Vietnam, Dà Lat region.