Side Lighting Enhances Morphophysiology and Runner Formation by Upregulating Photosynthesis in Strawberry Grown in Controlled Environment

The significant effects of lighting on plants have been extensively investigated, but research has rarely studied the impact of different lighting directions for the strawberry plant. To understand the optimal lighting direction for better growth and development, this study investigated how strawberries respond to variations in the lighting direction to help fine-tune the growth environment for their development. We examined how the lighting direction affects plant morphophysiology by investigating plant growth parameters, leaf anatomy, epidermal cell elongation, stomatal properties, physiological characteristics, and expressions of runner induction-related genes (FaSOC1 and FaTFL1) and gibberellin (GA) biosyntheses-related genes (FaGA20ox2 and FaGA20ox4). In closed-type plant factory units, the rooted cuttings of strawberry (Fragaria × ananassa Duch.) ‘Suhlyang’ were subjected to a 10-h photoperiod with a 350 μmol∙m−2∙s−1 photosynthetic photon flux density (PPFD) provided by light-emitting diodes (LEDs) from three directions relative to the plants: top, side, and bottom. Our results demonstrated that the side lighting profoundly promoted not only morphophysiology, but also runner formation, by upregulating photosynthesis in strawberries. Side lighting can bring commercial benefits, which include reduced economic costs, easier controllability, and harmlessness to plants. This will help provide new insights for the propagation of the most commonly cultivated strawberries in South Korea.

Pengaruh Pemberian Naungan Terhadap Aklimatisasi Planlet Strowberi Varietas Dorit dan Varietas Lokal Berastagi

Strawberry plant tissue culture techniques have been successful in plantlet propagation. In order to produce strawberry seeds that are ready for planting, plantlets must go through the acclimatization stage. A modified growing environment with a plastic hood or housing needs to be considered to provide optimal environmental conditions for the acclimatization of strawberry plantlets. This study aimed to describe the effect of shading and type of variety on plantlet acclimatization of the Dorit variety and the local Berastagi variety. This research was experimental with RAK using 2 factors, namely shade with the plastic thickness of 0.17 mm and 0.12 mm and types of local varieties of Berastagi and Dorit varieties. Parameters observed were climate data, vegetative growth (percentage of plantlets growing, number of stolons, diameter of stolons, number of leaves). The data were analyzed with Anova 2 factors; if the results were significant, it would be continued with Duncan's test. The results showed that the shade had a significant effect on the growth of strawberry plantlets. In contrast, the variety had a significant effect on the vegetative growth of strawberries, and the variety with the best growth was the Berastagi variety.

Optimal Siting and Sizing of Distributed Generators by Strawberry Plant Propagation Algorithm

Increasing the unplanned penetration of Distributed Generators (DGs) has spurred active and reactive power losses in the distribution system. This article suggests using a novel Strawberry Plant Propagation Algorithm (SPPA) for planning the placement of the DGs with the aim of reducing the network (active) power losses and improving the overall voltage profile. The proposed method (SPPA) has been tested on 33 and 69 node radial systems in MATLAB. A cost analysis was also performed and compared with other contemporary methods. The results for the considered variables show the significance of the proposed method in comparison to various other counterparts, including the Mine Blast Algorithm and Particle Swarm Optimization.

Down-regulation of Fra a 1.02 in strawberry fruits causes transcriptomic and metabolic changes compatible with an altered defense response

The strawberry Fra a 1 proteins belong to the class 10 Pathogenesis-Related (PR-10) superfamily. In strawberry, a large number of members have been identified, but only a limited number is expressed in the fruits. In this organ, Fra a 1.01 and Fra a 1.02 are the most abundant Fra proteins in the green and red fruits, respectively, however, their function remains unknown. To know the function of Fra a 1.02 we have generated transgenic lines that silence this gene, and performed metabolomics, RNA-Seq, and hormonal assays. Previous studies associated Fra a 1.02 to strawberry fruit color, but the analysis of anthocyanins in the ripe fruits showed no diminution in their content in the silenced lines. Gene ontology (GO) analysis of the genes differentially expressed indicated that oxidation/reduction was the most represented biological process. Redox state was not apparently altered since no changes were found in ascorbic acid and glutathione (GSH) reduced/oxidized ratio, but GSH content was reduced in the silenced fruits. In addition, a number of glutathione-S-transferases (GST) were down-regulated as result of Fra a 1.02-silencing. Another highly represented GO category was transport which included a number of ABC and MATE transporters. Among the regulatory genes differentially expressed WRKY33.1 and WRKY33.2 were down-regulated, which had previously been assigned a role in strawberry plant defense. A reduced expression of the VQ23 gene and a diminished content of the hormones JA, SA, and IAA were also found. These data might indicate that Fra a 1.02 participates in the defense against pathogens in the ripe strawberry fruits.

Phenotypic Characteristics of Strawberry related to Photo-physiological Parameters according to Temperature and Relative Humidity in a Greenhouse after Planting

The low relative humidity (RH) levels in a greenhouse during the daytime in a strawberry (Fragaria × ananassa Duch) cultivation period negatively affect the growth of strawberry related to photo-physiology. Therefore, this study was conducted to confirm an efficient RH management method by analyzing the phenotypic characteristics related to photo-physiology by controlling the RH in a greenhouse during the daytime with a fog system. Strawberry plants were grown respectively in a greenhouse affected by natural RH changes (control) and in a greenhouse with 40% ~ 50% RH adjusted during the daytime using a fog system. In the greenhouse, with controlled RH, the temperature decreased, and the RH was higher in the initial growth stage of strawberry planting than the control. It was observed a significant increase in the survival rate of the strawberry plant, as well as the incidence of powdery mildew, was lowered. In addition, the photosynthetic rate and OJIP chlorophyll a fluorescence transients related to photosystem II efficiency of strawberry leaves were significantly higher in the fog treatment than in the control. In winter, during the day, the number of days on which the temperature dropped below 20℃ has increased, the greenhouse temperature with controlled RH was lower due to the fog system. When the yield per strawberry plant in January and February was investigated, the control was higher than the RH treatment. Therefore, RH management using a fog system must be controlled at a level where a temperature range is adequate for plant growth, in which the efficient control of these parameters increases strawberry productivity.