Chemcial fertilizer as the main strategy for improving the vegetable yields was excessively applied in recent years which led to progressively serious soil problems such as the soil acidification. According the situation, five different biofertilizer treatments [no fertilizer (CK), inoculations of Bacillus subtilis (Bs, T1), combination of Bs and Bacillus mucilaginosus (Bs+Bm, T2), Bs and Bacillus amyloliquefaciens (Bs+Ba, T3), and Bm+Ba (T4)] were conducted to investigate the effect of the growth, leaf physiological indices, and chlorophyll fluorescence of spinach seedlings in the growth chamber. The growth and physiological indices of the spinach seedlings attained a maximum under the T2 treatments. Under the T2 treatment, the ABS/RC (Absorption flux per RC), TR₀/RC (Trapping flux per RC), and ET₀/RC (Electron transport flux per RC) was significantly increased, while the DI₀/RC [Dissipated energy flux per RC (at t = 0)] was decreased. The OJIP curve was improved under of the inoculations of fertilizers, and the increasing range was the largest under the T2 treatment. The leaf light response curve (LC) was also significantly increased under the T2 treatment. The plant growth characteristics [leaf length (LL), leaf weight (LW), plant height (PH)] were positively correlated with the J-I-P test chlorophyll fluorescence parameters [PI_ABS (Performance index for energy conservation from exciton to the reduction of intersystem electron acceptors), φP₀ (Maximum quantum yield of primary photochemistry), φE₀ (Quantum yield of electron transport), ψ₀ (The probability that a trapped exciton moved an electron in electron transport chain further than QA^-), TR₀/RC, and ET₀/RC] while negatively correlated with φD₀ (Quantum yield of energy dissipation) and DI₀/RC. The leaf physiological characteristics [SP (soluble protein concentrations), SC (soluble carbohydrate concentrations), Chl a (chlorophyll a), Chl b (chlorophyll b), Chl a+b, Chl a/b, and WP (water potential)] were positively correlated with the J-I-P test chlorophyll fluorescence parameters (PI_ABS, φP₀, φE₀, ψ₀, ABS/RC, TR₀/RC, and ET₀/RC) while negatively correlated with φD₀ and DI₀/RC. These results indicated that the combination of Bs+Bm inoculations promoted the growth of the spinach and improved the adaptability of the vegetable to acid soil while Ba inoculation didn’t have any effects to plants.

Approximately 94% of the land area of the Northern Tibetan Plateau is covered by grasslands, which comprise one of five key livestock producing regions in China. In contrast to most other regions worldwide, these alpine grasslands are much more sensitive to global climate change, thus they are under intense study. The differences in species diversity, plant biomass, and soil properties of five representative’s alpine grassland types in the Northern Tibetan Plateau were investigated in this research. The results revealed that 11 community types were identified according to the importance of dominant species and constructive species. There were significant differences in the Margalef index (H), Simpson diversity index (D), Shannon-wiener diversity index (H'), and Pielou evenness index (J) indices between these five alpine grasslands. Further, the above-ground biomass (AGB), below-ground biomass (BGB), total biomass (TB), root:shoot (R/S) ratio, and coverage showed significant differences in 5 alpine grasslands. There were also considerable variations in the pH, total nitrogen concentration (TN), total phosphorus concentration (TP), soil organic carbon (SOC) and C-to-N ratio (C:N) among the five alpine grasslands. The highest value of biomass and soil characteristics was always in the alpine steppe (AS), or AM, while the lowest of that was in the alpine desert steppe (ADS), or alpine desert (AD). Moreover, there were significant differences in the soil particle size fractions between the five alpine grasslands. In the AM and AS, the dominant soil particle was clay, while in the alpine meadow-steppe (AMS), ADS, and AD it was fine and medium sand. Substantial correlations were found between the biomass and species diversity indices H, D or H' and soil TN, TP, or SOC. Moreover, silt had a significantly positive correlation with soil C:N, BGB, TB, and R/S, while medium sand and coarse sand was significant negatively correlated. With regard to these grassland types, it is proposed that the AM or AS may be an actively changing grassland types in the Northern Tibetan Plateau.

Drought stress greatly affected the growth and development of wheat in the world, while wheat growth could benefit through improvement of water status and nutrient uptake by mycorrhizal symbiosis or addition of phosphorus (P). Experimental treatments were (a) phosphorus addition (0 and 90 kg/ha), (b) soil water condition (40% field capacity and 95% field capacity), and (c) arbuscular mycorrhizal fungi (AMF, Glomus intraradices) (noninoculation and inoculation) which were conducted in a growth chamber. The results showed that addition of phosphorus and AMF inoculation significantly increased the relative water content and specific leaf area of flag leaves especially under 40% field capacity (water deficit (WD)). The leaf gas exchange parameters were all decreased under WD. The water use efficiency (WUE) and instantaneous WUE (WUEi) was enhanced by WD, AMF inoculation, and phosphorus addition. AMF inoculation and WD significantly decreased the carbon isotope discrimination (CID) of leaf. The P concentrations in stem, grain, and leaf were significantly increased by phosphorus addition, WD, and AMF inoculation. Significant correlations were found between WUE and grain P, stem P, and leaf P concentrations. Leaf CID was significantly negatively correlated with WUE and stem P concentrations. Inoculation of AMF or phosphorus addition could improve the growth, physiology, and phosphorus uptake in spring wheat under drought conditions.

With the expeditious development of optoelectronics, the light-emitting diode (LED) technology as supplementary light has shown great effects to landscape plants. In urban areas, artificial lighting alters natural light conditions, potentially affecting plant performance. In current study, the six light intensities (100–600 µmol/(m²·s)) and their effects on growth attributes, indices of chlorophyll fluorescence (CF) and thermoluminescence (TL) in seedlings of perennial ryegrass (Lolium perenne L.) was investigated. Results showed that moderate light intensity (300–400 µmol/(m²·s)) enhanced germination, biomass accumulation, chlorophyll content, and photosynthetic efficiency, while higher and lower intensities (100 and 600 µmol/(m²·s)) induced oxidative stress, reduced photosynthetic activity, and altered electron transport in photosystem II (PSII). CF analysis revealed impaired photochemical efficiency under higher and lower light, supported by decreased Fv/Fm and performance index (PI_ABS). TL measurements indicated disruptions in PSII charge recombination under stress, with the disappearance of the B band and emergence of the afterglow (AG) band. These findings suggested that perennial ryegrass showed the highest performance under moderate light but exhibited indicators of photoinhibition and oxidative stress under extreme intensities, highlighting the need for optimized artificial lighting in urban green spaces.

We investigated the effects of different types of bacillus on the growth, physiological characteristics, and chlorophyll fluorescence of spinach seedlings in the soil environment of a Qinxi demonstration garden in Taibai County. Five different fertilization treatments were conducted in the growing room: no fertilizer (CK), addition of Bacillus subtilis (Bs, T1), addition of Bs and Bacillus mucilaginosus (Bm) (T2), addition of Bs and Bacillus amyloliquefaciens (Ba) (T3), and addition of Bs and Ba (T4). There were significant differences in the plant height (PH), leaf length (LL), and leaf weight (LW) of the spinach seedlings (F=54.37, 13.30, and 46.03, respectively; P<0.01). The growth and physiological characteristics of the spinach seedlings attained a maximum under the Bs and Bm treatments. There were differences in the activities of the PSII reaction centers between the five treatments. Under the Bs and Bm treatments, the ABS/RC, TR₀ /RC, and ET₀ /RC increased significantly, while the DI₀ /RC decreased. The OJIP curve increased under different types of fertilization, and the growth trends under the Bs and Bm treatments were the largest. The leaf light response curve (LC) increased significantly under the Bs and Bm treatments. The plant growth characteristics (LL, LW, PH) were positively correlated with the J-I-P test chlorophyll fluorescence parameters (PI_ABS, φP₀, φE₀, ψ₀, TR₀/RC, and ET₀/RC), and negatively correlated with φD₀ and DI₀/RC. The leaf physiological characteristics (SP, SC, Chla, Chlb, Chla+b, Chla/b, and WP) were positively correlated with the J-I-P test chlorophyll fluorescence parameters (PI_ABS, φP₀, φE₀, ψ₀, ABS/RC, TR₀ /RC, and ET₀ /RC), and negatively correlated with φD₀ and DI₀ /RC. The leaf MDA was significantly positively correlated with φD₀ and DI₀ /RC, and positively correlated with other J-I-P test chlorophyll fluorescence parameters. The Bs and Bm treatments promoted the growth of the spinach seedlings and improved the adaptability of the crops to soil by enhancing the effective phosphorus utilization rate.