Investigating Planting Concrete Suitability by Evaluating the Physiological Indexes of Three Ground Cover Plants

Concrete is one of the most widely used construction materials for basic infrastructure worldwide, especially in developing areas undergoing rapid urbanization. However, concrete inhibits energy exchange between soil and other ecosystem components. To enhance the fluxion of information between ecosystems, surface vegetation, and basement soil, this paper aims to explore the tolerance of plants growing on PC. Therefore, we investigated two different PC sample groups with aggregate particle diameters of 5–10 and 15–20 mm. After curing, the samples were used to plant three ground cover plants (Cynodon dactylon (L.) Pers, Agrostis stolonifera, and Sasa argenteostriatus, e.g., Camus), and the results were compared with those from normal soil without PC underneath as a reference. During an observational period of 12 weeks, the growth and height of the plants were documented and analysed. The physiological indexes of free proline (Pro), malondialdehyde (MDA), chlorophyll (Chl), relative electrical conductivity (REC), and soluble protein (SP) were investigated. The correlations and significant differences between these indexes based on the treatments were analysed. Then, principal component analysis (PCA) was used to determine the main variables affecting plant growth. The results showed that there were significant differences between the PC groups and the natural growth group. The growth and height of the three plant species under near-natural (nonconcrete) conditions were better than those of the plants in the PC treatments. The plants in the large-particle concrete (LC) treatment group showed better adaptability than those in the small-particle concrete (SC) treatment group in terms of growth, although both PC treatments resulted in various degrees of damage. PCA showed that SP, REC, and MDA were the most influential factors on plant growth in this study.

Physiological and Gene Expression Responses of Six Annual Ryegrass Cultivars to Cobalt, Lead, and Nickel Stresses

Heavy metals negatively affect soil quality and crop growth. In this study, we compared the tolerance of six ryegrass cultivars to cobalt (Co2+), lead (Pb2+), and nickel (Ni2+) stresses by analyzing their physiological indexes and transcript levels of genes encoding metal transporters. Compared with the other cultivars, the cultivar Lm1 showed higher germination rates and better growth under Co2+, Pb2+, or Ni2+ treatments. After 48 h of Co2+ treatment, the total antioxidant capacity of all six ryegrass cultivars was significantly increased, especially that of Lm1. In contrast, under Pb2+ stress, total antioxidant capacity of five cultivars was significantly decreased, but that of Lm1 was unaffected at 24 h. Staining with Evans blue dye showed that the roots of Lm1 were less injured than were roots of the other five ryegrass cultivars by Co2+, Pb2+, and Ni2+. Lm1 translocated and accumulated lesser Co2+, Pb2+, and Ni2+ than other cultivars. In Lm1, genes encoding heavy metal transporters were differentially expressed between the shoots and roots in response to Co2+, Pb2+, and Ni2+. The aim of these researches could help find potential resource for phytoremediation of heavy metal contamination soil. The identified genes related to resistance will be useful targets for molecular breeding.

The Effects of Soundscapes in Relieving Stress in an Urban Park

Urban parks are important urban public spaces that guarantee people recreation, create positive emotions and relieve stress. Emerging research has shown that natural soundscapes are associated with restorative landscapes in urban parks. However, there is still a lack of knowledge on the use of physiological indexes to evaluate the effects of natural sounds versus human-based sounds on stress relief. In this study, the three physiological indexes of skin conductance level, heart rate and heart rate variability were collected in Fuzhou West Lake Park with the help of Ergo LAB data platform, and a soundscape perception evaluation questionnaire was used to assess the degree of soundscape perceptions in the sample sites. The differences in the stress relieving effects of different urban park environments were analysed by applying the median test, the Wilcoxon test was applied to analyse the effects of soundscapes and urban park environments on relieving stress, and regression analysis was used to identify the important factors of restorative soundscapes. The results found that urban park environments provide a certain degree of stress relief, but the stress relieving effects of different urban park environments vary and that natural spaces play an important role in relieving stress. Urban park soundscapes are key to restorative environmental design, with natural sounds such as birdsong and stream sound being important factors of restorative soundscapes.

Ovary Abortion Induced by Combined Waterlogging and Shading Stress at the Flowering Stage Involves Amino Acids and Flavonoid Metabolism in Maize

Maize (Zea mays L.) crops on the North China Plain are often subject to continuous overcast rain at the flowering stage. This causes waterlogging and shading stresses simultaneously and leads to huge yield losses, but the causes of these yield losses remain largely unknown. To explore the factors contributing to yield loss caused by combined waterlogging and shading stress at the flowering stage, we performed phenotypic, physiological, and quasi-targeted metabolomics analyses of maize plants subjected to waterlogging, shading, and combined waterlogging and shading (WS) treatments. Analyses of phenotypic and physiological indexes showed that, compared with waterlogging or shading alone, WS resulted in lower source strength, more severe inhibition of ovary and silk growth at the ear tip, a reduced number of emerged silks, and a higher rate of ovary abortion. Changes in carbon content and enzyme activity could not explain the ovary abortion in our study. Metabolomic analyses showed that the events occurred in ovaries and silks were closely related to abortion, WS forced the ovary to allocate more resources to the synthesis of amino acids involved in the stress response, inhibited the energy metabolism, glutathione metabolism and methionine salvage pathway, and overaccumulation of H2O2. In silks, WS led to lower accumulation levels of specific flavonoid metabolites with antioxidant capacity, and to over accumulation of H2O2. Thus, compared with each single stress, WS more seriously disrupted the normal metabolic process, and resulted more serious oxidative stress in ovaries and silks. Amino acids involved in the stress response in ovaries and specific flavonoid metabolites with antioxidant capacity in silks play important roles during ovary abortion. These results identify novel traits for selection in breeding programs and targets for genome editing to increase maize yield under WS stress.

Fermentation quality of herbal tea residue and its application in fattening cattle under heat stress

Background Herbal tea residue (HTR) is generally considered to be the waste of herbal tea beverage production while it still retains rich nutrients and active substances. The main aim of the present study was to investigate the effect of fermentation technology on improving the quality of HTRs, and focus on the fermented HTR-induced alleviation of summer heat stress in fattening cattle. Results In this study, the waste HTR was fermented and then fed to a total of 45 fattening cattle that were divided into 3 groups (fermented HTR replaced 0, 15, 30% of the forage component of the diet), and the feeding experiment was lasted for 40 days. The physiological indexes, growth performance and fecal microbiota of fattening cattle were evaluated and results showed that fermented HTR could effectively reduce the respiratory rate and rectal temperature of fattening cattle under heat stress, increase the daily feed intake and daily gain, and improve the antioxidant content and blood immune index. In addition, we studied the fecal microbiota composition of 6 fattening cattle in control and 30% HTR substitution groups and found fermented HTR significantly changed the composition of fecal microbiota and increased microbial diversity, and correlation analysis suggested that the bacteria were closely related to fecal SCFA levels of fattening cattle under heat stress. Conclusions In this study, fermented HTR replaced 30% of the forage component of the diet that can change the intestine microorganisms, maintain health and alleviate the heat stress of fattening cattle.

Biochar increases tobacco yield by promoting root growth based on a three-year field application

In order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.

Effects of mixed irrigation using brackish water with different salinities and reclaimed water on a soil-crop system

To explore the effects of mixed irrigation on soil and crops, a pot experiment was conducted in two salinity levels of brackish water, four levels of mixed brackish-reclaimed water and freshwater irrigation as the control. The soil Na-Cl to Ca-SO4 contents changed, and activities of soil alkaline phosphatase and polyphenol oxidase changed, exhibiting a ‘V’-shaped curve with increasing the proportion of reclaimed water in the mixture. At the same brackish-reclaimed water level, there were no significant differences in alkaline phosphatase and polyphenol oxidase activities except for soil alkaline phosphatase activity decreasing significantly with the increase in salinity under brackish water irrigation. Mixed irrigation obviously improved superoxide dismutase activity but no significant influences on aboveground dry weight, underground biomass or crop physiological indexes (chlorophyll, soluble protein, malondialdehyde, peroxidase, catalase). Based on the integrated biological response index version 2 (IBRv2), the deviation of reclaimed water irrigation was the smallest, followed by 1:1 and 1:2 (3, 5 g/L brackish water salinities, respectively), with IBRv2 values of 7.94, 12.55 and 16.04. Therefore, considering the soil-crop characteristics, limited daily water amount and inadequate pipeline facilities for reclaimed water, the brackish-reclaimed water ratio should be 1:1 and 1:2 at 3, 5 g/L of brackish water, respectively.

Ovipositor sources for queen-rearing of honey bee (Apis mellifera) revealed inheritable maternal effect on reared queen

Queen is arguably the most important member of a honey bee colony, and queen quality is crucial for honey bee colony growth and development. In this study, queens were reared with eggs laid in queen cells (QE), eggs laid in worker cells (WE) and 2-day old larvae in worker cells (L). Those physiological indexes (the weight, thorax size and number of ovarioles) of newly reared queens in each group were measured. Moreover, the reproductive potential of the newly reared queens and foraging ability of worker bees laid by the newly reared queens in each group were further explored. In addition, we also examined whether maternal effects would be transmitted to the offspring queens in honey bee. We found that the weight, number of ovarioles and thorax weight of newly emerged queens in QE were significantly higher than those in WE and L, suggesting the reproductive potential was stronger in QE group than WE and L group. Furthermore, offspring worker bees and queens of QE queens had higher weight at emergence than those from the other two groups. This study proved profound honey bee maternal effects on queen quality, which can be transmitted to their offspring. Our results of the present study were important for improving queen quality and promoting the development of beekeeping and agriculture.

Fermentation Quality of Herbal Tea Residue and its Application in Fattening Cattle Under Heat Stress

Background: Herbal tea residue (HTR) is generally considered to be the waste of herbal tea beverage production while it still retains rich nutrients and active substances. The main aim of the present study was to investigate the effect of fermentation technology on improving the quality of HTRs, and focus on the fermented HTR-induced alleviation of summer heat stress in fattening cattle.Results: In this study, the waste HTR was fermented and then fed to a total of 45 fattening cattles that were divided into 3 groups (fermented HTR replaced 0%, 15%, 30% of Pennisetum purpureum respectively), and the feeding experiment was lasted for 40 days. The physiological indexes, growth performance and fecal microorganisms of fattening cattle were evaluated and results showed that fermented HTR could effectively reduce the respiratory rate and rectal temperature of fattening cattle under heat stress, increase the daily feed intake and daily gain, and improve the antioxidant content and blood immune index. In addition, we studied the fecal microorganisms composition of 6 fattening cattles in each group and found fermented HTR significantly changed the composition of fecal microorganisms and increased microbial diversity, and correlation analysis suggested that the bacteria were closely related to fecal SCFA levels of fattening cattle under heat stress. Conclusions: we suggested that 30% of fermented HTR can help maintain health of fattening cattle and alleviate the heat stress of fattening cattle by the change of intestine microorganisms.

Comparing Rooting Ability and Physiological Changes of Two Eucommia ulmoides Improved Varieties

Eucommia ulmoides (E. ulmoides) is a significant national strategic resource in China. It is a natural high quality rubber resource, with great development potential. We found large differences in rooting ability during adventitious root (AR) formation in two E. ulmoides improved varieties. Therefore, we used two improved varieties of E. ulmoides, ‘Huazhong 6’ (H6, with rooting rate 85.3%) and ‘Huazhong 8’ (H8, with rooting rate 22.5%) to explore the cutting rooting mechanism. In this study, we mainly determined the morphological development process of E. ulmoides cutting rooting, and compared the rooting-related indexes of the two improved varieties, and the changes in physiological indexes closely related to rooting, which include endogenous hormones, oxidases and nutrients in the phloem of the basal stem. The results showed that indole–3–acetic acid (IAA), zeatin riboside (ZR), IAA/ZR and indoleacetic acid oxidase (IAAO) were the key factors that caused big differences in rooting ability between the two E. ulmoides improved varieties. The increase in endogenous hormone IAA content and IAA/ZR value were necessary for the formation of AR. The increase in IAA content was beneficial to AR formation. The activity of IAAO was significantly negatively correlated with the rooting ability of the E. ulmoides cuttings. The high IAAO activity of the H8 cuttings led to the consumption of IAA. Although the content of IAA increased, the rooting conditions were not reached. The accumulation of nutrients before rooting also has an important effect on rooting; it is easy for cuttings to root when the carbon–nitrogen ratio (C/N) value is high. This research provides an improved understanding of the cellular and physiological underpinnings of the AR process in woody plants. In addition, it provides a theoretical basis and foundation for subsequent research on E. ulmoides cuttage technology.