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Abstract

China aster and gaillardia are flowering plants with high economic importance in floriculture. In the present investigation, response of China aster and gaillardia seedlings to inoculation with the arbuscular mycorrhizal fungus Funneliformis mosseae + the plant growth-promoting rhizobacterium Bacillus sonorensis was studied by growing in multipots (pro trays). The germination percentage and plant growth parameters: length of shoots, roots and whole seedlings, stem diameter, biovolume index, plant strength, vigor index, dry weight and nutrient uptake, were analyzed 60 days after sowing. The microbial parameters, mycorrhizal root colonization and spore count, and the population of B. sonorensis in the substrate were also determined. The results brought out that growth of inoculated seedlings was significantly improved as compared to uninoculated seedlings. Based on the plant growth and microbial parameters studied, it was concluded that inoculating the substrate in pro trays with the microbial consortium results in producing vigorously growing seedlings.

Abstract

Fungal diseases are a persistent problem in the cultivation of white button mushrooms (Agaricus bisporus). The chemical control of pathogens is becoming less effective and less desirable, so new ways to limit these infections are urgently required. What is more, the disease is mostly controlled through cultural practices and good hygiene on mushroom farms. The aim of this study was to evaluate the fungicidal effects of ozone on fungal pathogens of common mushrooms. Experiments with the use of ozone gas for disinfection of growing rooms after the completion of the mushroom growing cycle were carried out. The fungicidal effectiveness of ozone fumigation was evaluated on the basis of the survival rate of the spores of the pathogens tested (Lecanicillium fungicola, Cladobotryum dendroides, Mycogone perniciosa, and Trichoderma aggressivum). Spore suspension was applied to aluminum plates and then was exposed to gaseous ozone. The assessment of the growth of colonies of fungal isolates obtained from infected surfaces was carried out using Rodac contact test plates. The results showed that L. fungicola, M. perniciosa, and C. dendroides isolates were sensitive to the gas ozone. In order to achieve 100% efficacy against Mycogone strains, a minimum of 6 hours of ozonation had to be applied, whereas for Cladobotryum strains, a minimum of 8 hours had to be applied. The Lecanicillium species was the most sensitive to ozonation because 30 minutes of ozonation was enough to gain 100% inhibition of its growth. No satisfactory results were obtained in the case of the pathogenic species of Trichoderma, regardless of the experimental conditions. Nevertheless, this study has demonstrated the usefulness of ozone as a disinfectant for empty growing rooms after the completion of the mushrooms’ cultivation cycle.

Abstract

Ex vitro rooting and acclimatization of two cultivars ‘Wojtek’ and ‘Zojka’ of blue honeysuckle (Lonicera caerulea var. kamtschatica Sevast.) were studied. To the ex vitro conditions were transferred rooted and unrooted shoots. The post-effect of auxin type and concentration as well as microcutting and soil substrate types were tested. The genetic stability of the plantlets in relation to the mother plants by using amplified fragment length polymorphism (AFLP) and inter simple sequence repeat (ISSR) markers has been also determined. It has been found that in vitro rooted cuttings of both cultivars showed a higher survival rate (max. 88%) and better growth and development when they were rooted on a medium containing a low auxin level (1.0 mg·dm−3). The results of the second experiment showed successful ex vitro rooting of blue honeysuckle shoots without auxin treatment. Higher ex vitro rooting and survival rate in the greenhouse have been observed for ‘Wojtek’ (max. 96%) than ‘Zojka’ (max. 88%). Better growth and development of shoots and roots were observed on peat alone or a mixture of peat and perlite as compared to a mixture of peat and sand. The micropropagated plantlets appeared similar to mother plants. Molecular analysis confirmed a high level of genetic stability of blue honeysuckle after 2 years of in vitro propagation. However, among the cultivars studied, ‘Wojtek’ showed slightly higher genetic stability than ‘Zojka’ (99.5% and 97.7%, respectively). For ‘Zojka’ plants, the degree of variation was comparable for AFLP and ISSR markers. For ‘Wojtek’, no polymorphism was detected using the ISSR analysis in contrast to the AFLP analysis.

Abstract

The activity of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO; EC 1.4.3.3) in germinating seeds of Callistephus chinensis was studied. For maximum recovery of ACO activity in vitro, the presence of 10% (w/v) insoluble polyvinylpolypyrrolidone (PVPP) and 30% of glycerol in the extraction medium was necessary. The optimum pH for this activity was 7.0. Ethylene production by whole achenes or enzymatic extract increased due to increasing 1-aminocyclopropane-1-carboxylic acid (ACC) concentrations. Saturation level of ACC for in vivo ACO activity was 10−1 M and Vmax was 10.89 nL C2H4·mg protein−1·h−1. For in vitro ACO activity, the saturation level of ACC was 10−3 M and Vmax was 2.299 nL C2H4·mg protein−1·h−1. Both, in vivo and in vitro ACO activities did not follow Michaelis-Menten kinetics. The Hill coefficients (h) were estimated on the basis of non-linear estimation. Their values were 0.63 for in vivo ACO activity and 1.73 for in vitro ACO activity. The experimental data show that ACO from C. chinensis seeds is an oligomeric enzyme with at least two active sites. During seed germination, in vitro ACO activity was detectable after 12 hours of imbibition, while in vivo ACC conversion to ethylene was observed after 24 h, i.e. – after radicle protrusion. The activity of ACO in C. chinensis seeds is associated with germination sensu stricto, and might be a good marker of this process.

Abstract

The impact of light quality generated by light-emitting diodes (LEDs) on the adventitious root formation and cuttings’ quality of rose hip ‘Konstancin’ under controlled conditions in multilevel growth chamber without access to natural light and in the greenhouse was evaluated. In the growth chamber, the lighting was provided by a combination of red and blue LED arrays and white LED tubes, while in the greenhouse, red and blue LED lights were used as a supplement to natural light. The number of rooted cuttings under both growth conditions was not affected by the light conditions generated by LEDs. However, light quality showed significant effects on the biomass production and development of adventitious roots, with the most stimulating red light generated by LEDs. In the growth chamber, the root biomass of the cuttings illuminated with white LEDs supplemented with red LEDs was on average 2.2 times higher than of the cuttings illuminated with white LEDs only. A similar reaction was noted under greenhouse conditions. Supplementation of natural light with red LEDs resulted in 1.7 times increase of the fresh biomass of roots. Both in the growth chamber and in the greenhouse, illumination with red LEDs promoted axillary bud outgrowth. LED lamps can be used in the production of high-quality rose cuttings, both in greenhouses as a complement to natural light and in multilevel rooms as a sole-source lighting for plants.

Abstract

This study aimed to evaluate yield parameters, antioxidant activity (AOA), total polyphenol content (TPC) and total soluble solids (TSS) in beetroot cultivars with different flesh colours. Field experiments were established at the Slovak University of Agriculture in Nitra in 2016 and 2017. Within the study, 16 beetroot cultivars were tested, including 11 red-fleshed (‘Boltardy’, ‘Boro’ F1, ‘Crosby Egyptian’, ‘Cylindra’, ‘Detroit Globe’, ‘Detroit 2’, ‘Egyptian Turnip Rooted’, ‘Opolski’, ‘Pablo’ F1, ‘Renova’ and ‘Taunus’ F1), 2 yellow-fleshed (‘Boldor’ F1 and ‘Golden’), 2 white-flesh cultivars (‘Albino’ and ‘White Detroit’) and 1 red-white fleshed cultivar (‘Chioggia’). All beetroot cultivars with red flesh colour showed higher AOA and TPC than different-coloured beetroot cultivars. The highest root yield was found in the white-fleshed beetroot cultivar ‘Albino’ (37.80–41.91 t · ha−1). The highest root weight was found in the white-fleshed beetroot cultivar ‘White Detroit’ (362.4–412.1 g). The highest AOA (819.19–972.50 mg TEAC · kg−1 d.w.) and TPC (2,387.70–2,731.00 mg · kg−1 d.w.) were found in the red-fleshed beetroot cultivar ‘Pablo’ F1. Different-coloured cultivars of beetroot were characterised by a lower content of TSS (6.4–8.8 ºBRIX) than cultivars with typical, red flesh colour (7.8–10.8 ºBRIX). Results clearly indicate that cultivar, or flesh colour, is showed as a significant factor influencing the quality of beetroot. Knowing of yield potential and quality of beetroot cultivars is important for growers as well as consumers. Results of this study indicate that white-fleshed cultivars of beetroot are characterised by high yield potential but lower quality, including lower AOA, TPC and TSS.

Abstract

Nucellar embryony is the major obstacle in getting hybrid seedlings in interspecific crosses in citrus. Hence, the present study was conducted to standardize embryo age, culture media for maximizing germination, and subsequent identification of simple sequence repeat (SSR) markers to differentiate the hybrids. A factorial experiment was conducted with three embryo ages – 80–90, 110–120, and 130–140 days after pollination (DAP). The germination of the rescued immature embryos of acid lime × lemon crosses was initiated on three different growing media. The fruits harvested at 130–140 and 80–90 DAP had a higher number of functional seeds (90%). Older embryos (130–140 DAP) and middle-aged embryos (110–120 DAP) germinated in 100% on Murashige and Skoog (MS) medium supplemented with 500 mg·l−1 malt extract, 1.5 mg·l−1 gibberellic acid (GA3), and 0.02 mg·l−1 naphthalene acetic acid (NAA). MS medium supplemented with 500 mg·l−1 malt extract proved better for the germination of embryos taken at 80–90 DAP. Plantlet survival was the highest in younger embryos (80–90 DAP) cultured on MS basal medium (84.21%) and the lowest in older embryos cultured on MS medium supplemented with 500 mg·l−1 malt extract plus 1.5 mg·l−1 GA3 and 0.02 mg·l−1 NAA. The seedlings obtained from the culture 80–90 DAP had the highest root length (4.9 mm) and shoot length (5.3 mm) at 60 days after inoculation (DAI) on the above medium. SSR marker analysis revealed that CCSM-4 and CAC-33 markers expressed polymorphism between female and male parents, proving their ability to identify the hybrids of ‘Kagzi’ acid lime × ‘Konkan Seedless’ lemon.

Abstract

Fruit quality attributes are influenced by environmental, agronomic and genetic factors; both cultivars and growing conditions can vary substantially between UK production and imported fruit. This study aimed to record and dissect the most relevant fruit quality traits for berries imported into the UK in the winter months. Blackberry, blueberry, raspberry and strawberry fruit were imported from 11 countries into a Kent-based packhouse (UK) or purchased from major retailers between December 2018 and March 2019. Multiple fruit quality components were assessed for relative contribution towards a high “overall assessment” fruit quality score. It was found that strawberry and blackberry overall scores were affected by sweetness perception, whereas blueberry and raspberry organoleptics are more complex, with overall scores influenced by flavor perception. Multiple raspberry and strawberry fruit quality traits were found to be associated with genotypic differences, indicating a promising potential for genetic improvement through breeding. By contrast, the study findings suggest that there is less potential for genetic improvement in blueberry, and that the environment may have a large effect on blueberry fruit quality traits.

Abstract

Some morphological and physiological traits of seedlings in eight quince populations from seeds obtained in 2015 (350 progenies per population) were evaluated in 2017 and 2018. They resulted from open pollination of ‘Viduja’, KVD2 and KVD4 genotypes as well as from the crossings of ‘Viduja’ × KVD4, KVD2 × ‘Viduja’, KVD2 × KVD4, KVD4 × ‘Viduja’ and KVD4 × KVD2. Populations showed significant differences in some measured traits, including height and diameter of seedlings, canopy width, annual growth, leaf iron, and chlorophyll content, as well as catalase and peroxidase activities. Based on the results of descriptive statistics, a high variation coefficient was observed in canopy width, peroxidase activity, chlorophyll, and iron content traits. Results of simple correlation showed that there were significant positive correlations between leaf iron content and catalase activity as well as canopy width with both annual growth and leaf length. Cluster analysis among populations based on total traits divided the populations into four distinct groups. The role of the female parents was visible in reciprocal crosses of ‘Viduja’ × KVD4 and KVD2 × KVD4, but all populations with similar female parents were not grouped in the same clusters.