Development of Arbuscular Mycorrhizal Fungi-Organic Fertilizer Pellets Encapsulated with Alginate Film

A novel formulation consisting of arbuscular mycorrhizal fungi (AMF) spores mixed with sterilized organic fertilizer (AMF-F) encapsulated by an insoluble calcium alginate film was developed to enhance AMF efficacy and stability. The hardness of the pellets increased from 7–8 N to approximately 80 N by increasing the alginate concentration of the coating film from 1 to 3%. The AMF spore germination rate for the AMF and AMF-F pellets coated with calcium alginate films depended on the alginate concentration. A 2% sodium alginate formulation for the coating films resulted in optimal AMF spore germination rates and mechanical properties for handling, transport, and stability. The inclusion of a sterilized organic fertilizer in the encapsulated AMF-F pellets considerably induced AMF mycelial growth and helped prolong the shelf life of the pellets. In soil, the AMF-F pellets encapsulated with alginate initially degraded faster than the alginate-encapsulated AMF pellets. However, both types of pellets were fully degraded within 30 days. It was demonstrated that AMF and AMF-F could promote colonization and provided resistance to drought stress in maize potted plants

Physiological, Morphological Changes and Storage Root Yield of Sweetpotato [Ipomoea batatas (L.) Lam.] under PEG-Induced Water Stress

Sweetpotato is an important tuberous root crop rich in nutrients such as vitamins and carbohydrates, and can grow well in arid regions with less water consuming crop. The aim of this research was to evaluate the storage root yields, physiological, biochemical and morphological traits in sweetpotato cv. ‘Japanese Yellow’ subjected to polyethylene glycol (PEG)-induced water deficit. At harvest (4 months after planting) the number of storage roots per plant and storage root fresh weight in sweetpotato treated with 5% PEG (-0.54 MPa) in nutrient solution of hydroponic culture declined by 20.0% and 47.4% compared to the control without PEG, respectively. Leaf area and leaf dry weight significantly decreased by 85.6% and 95.3%, respectively when exposed to water deficit stress. Sucrose content (114.7 mg g-1 dry weight; DW) in storage roots of sweetpotato grown under PEG-induced water deficit conditions was enriched by 2.2 fold of control (52.5 mg g-1 DW) and was greater than in storage roots derived from soil culture (70.3 mg g-1 DW). Total soluble sugar in the root and storage root tissues was enriched and may play a key role as osmotic adjustment (OA) in PEG-induced water stressed plants. Free proline and sucrose contents were also dominated in the leaf tissues to maintain the leaf osmotic potential in water stressed plants. In addition, chlorophyll degradation, chlorophyll fluorescence diminution and stomatal closure were found in plants grown under PEG-induced water deficit conditions, leading to reduction in net photosynthetic rate (Pn) and subsequently lesser amounts of glucose and fructose contents in the leaf tissues. Sucrose and free proline in the roots of sweetpotato play a key role as major osmotic adjustment when subjected to PEG-induced water deficit condition. Basic knowledge gained from this research will further be investigated the drought defense mechanism in sweetpotato via osmoregulation system

Water-deficit tolerant classification in mutant lines of indica rice

Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica) genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC) in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control) and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control) as water deficit sensitive, using Ward's method

Water-Deficit Tolerance in Sweet Potato [Ipomoea batatas (L.) Lam.] by Foliar Application of Paclobutrazol: Role of Soluble Sugar and Free Proline

The objective of this study was to elevate water deficit tolerance by improving soluble sugar and free proline accumulation, photosynthetic pigment stabilization, photosynthetic abilities, growth performance and storage root yield in sweet potato cv. ‘Tainung 57’ using a foliar application of paclobutrazol (PBZ). The experiment followed a Completely Randomized Block Design with four concentrations of PBZ: 0 (control), 17, 34, and 51 μM before exposure to 47.5% (well irrigation), 32.3% (mild water deficit) or 17.5% (severe water deficit) soil water content. A sweet potato cultivar, ‘Japanese Yellow’, with water deficit tolerance attributes was the positive check in this study. Total soluble sugar content (sucrose, glucose, and fructose) increased by 3.96-folds in ‘Tainung 57’ plants treated with 34 μM PBZ grown under 32.3% soil water content (SWC) compared to the untreated plants, adjusting osmotic potential in the leaves and controlling stomatal closure (represented by stomatal conductance and transpiration rate). In addition, under the same treatment, free proline content (2.15 μmol g-1 FW) increased by 3.84-folds when exposed to 17.5% SWC. PBZ had an improved effect on leaf size, vine length, photosynthetic pigment stability, chlorophyll fluorescence, and net photosynthetic rate; hence, delaying wilting symptoms and maintaining storage root yield (26.93 g plant-1) at the harvesting stage. A positive relationship between photon yield of PSII (ΦPSII) and net photosynthetic rate was demonstrated (r2 = 0.73). The study concludes that soluble sugar and free proline enrichment in PBZ-pretreated plants may play a critical role as major osmoprotectant to control leaf osmotic potential and stomatal closure when plants were subjected to low soil water content, therefore, maintaining the physiological and morphological characters as well as storage root yield

Matching of Nitrogen Enhancement and Photosynthetic Efficiency by Arbuscular Mycorrhiza in Maize (Zea mays L.) in Relation to Organic Fertilizer Type

In the present study, Funneliformis mosseae (FM), Claroideoglomus etunicatum (CE), and Acaulospora foveata (AF) were inoculated to hybrid maize (Zea mays L. cv. CP888®). Upregulation of nitrogen levels were dependent on the type of mycorrhiza (AMF). Photosynthetic efficiency (Fv/Fm) and water content in FM- and AF-inoculated plants were elevated, resulting in promotion of leaf area and shoot biomass. N content in the shoot and root tissues of the FM-inoculated plants increased by 21% and 30% over the control. A positive correlation between biochemical, physiological, and morphological parameters using Pearson’s coefficient was demonstrated. A decline in lipid peroxidation was noticed in the FM-inoculated plants. In addition, we investigated the potential of N fertilizer application in combination with FM inoculation in maize plants. The FM-inoculated plants with organic O_LT, a chicken manure fertilizer, increased N content in the host shoots by 73% over the control, leading to improved Fv/Fm as a physiological adaptation strategy. The FM and the O_LT on the regulation of the N enhancement and photosynthetic efficiency of the hybrid maize should further be validated in field trials in different environments for sustainability

Hydrogen cyanamide enhances MRI-measured water status in flower buds of peach (Prunus persica L.) during winter

Abstract Braking bud dormancy in temperate fruit species using physical and chemical agents is a challenge issue. In present study, we investigated the interaction between hydrogen cyanamide (HC) and temperature in breaking dormancy to gain a basic knowledge on water status in peach (Prunus persica L.) floral buds. The water status, relaxation time (T 2 ) and apparent diffusion coefficient (ADC), in the upper part (flower primordia and bud scales), basal part, and bud trace of flower buds were determined using the magnetic resonance imaging (MRI). Bulk water, which might flow through the bud trace, increased the water content in the basal part, and water molecular mobility as reflected by an increase in T 2 in HC-treated buds after 1 week at 5C. The HC triggers the influx of water into the bud, where the basal part exhibited the highest level of water accumulation. The study provides significant insights into the status of water in floral buds and highlights the role of HC to solve the problems of produce in temperate fruits