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Screening for low-accumulation varieties is an effective way to reduce the cadmium (Cd) content in crops and decrease human Cd intake. In this study, a field experiment was conducted to analyze the characteristics of Cd absorption and accumulation in 24 maize varieties at maturity in farmland with different levels of Cd pollution. Cluster analysis and Pareto analysis methods were used to screen for maize varieties with low Cd absorption. In addition, the environmental threshold of Cd in farmland in the study area was estimated based on the Species Sensitivity Distribution (SSD) characteristics of different maize Cd enrichment coefficients (1/BCF). The results showed that maize in the study area was subject to varying degrees of Cd pollution, with total soil Cd content ranging from 1.81 to 2.71 mg·kg−1 at test site 1 and from 0.95 to 1.76 mg·kg−1 at test site 2. Only the Cd content of heavy metals in maize kernels at test site 2 did not exceed China's national food safety standard (GB 2762-2022, 0.1 mg·kg−1), with the Cd content of different maize varieties at test site 2 ranging from 0.008 to 0.073 mg·kg−1 and the bioconcentration factor (BCF) of maize kernels for Cd ranging from 0.004 to 0.054. According to cluster analysis and Pareto analysis, the low-Cd accumulation maize varieties suitable for local planting were identified as Yufeng 303, Nongda 372, Jingnongke 728, MC121 (Fengda Seed Industry), and Jinyu 1233. In addition, the soil Cd environmental threshold for ensuring that 95% of maize would not be polluted by Cd in soil was derived as 1.39 mg·kg−1. [ABSTRACT FROM AUTHOR]

The acquisition of the timing and duration of metamorphic mineral growth is the key to understanding the evolution of metamorphic belts. Garnet Lu–Hf geochronology is becoming increasingly powerful in this aspect. It is believed that garnet Lu–Hf radiometric systems are preserved during low-temperature metamorphism. However, this hypothesis has not been systematically tested. To examine the Lu–Hf systematics of garnets during low-temperature metamorphism, we conducted radiometric dating on individual garnet crystals of different sizes from a single micaschist in the North Qilian orogenic belt. The garnet Lu–Hf dates correlate well with the grain sizes and their core Mn concentrations. The positive correlation between the ages and grain sizes suggests that grain size is a proxy for preserving garnet nucleation and growth history. Small grains nucleated and grew later than large crystals. The Lu–Hf date of the individual garnet crystals faithfully recorded the total growth time span. The date difference of ~16 Myr is the minimum duration of the total garnet growth. The age discrepancy between the micaschist and the eclogite indicates they may not have experienced the same subduction and exhumation in the North Qilian orogenic belt. [ABSTRACT FROM AUTHOR]

Isolates of three endornavirus species were identified co-infecting an unidentified species of Ceratobasidium, itself identified as a symbiont from within the roots of a wild plant of the terrestrial orchid Pterostylis vittata in Western Australia. Isogenic lines of the fungal isolate lacking all three mycoviruses were derived from the virus-infected isolate. To observe how presence of endornaviruses influenced gene expression in the fungal host, we sequenced fungus-derived small RNA species from the virus-infected and virus-free isogenic lines and compared them. The presence of mycoviruses influenced expression of small RNAs. Of the 3272 fungus-derived small RNA species identified, the expression of 9.1% (300 of 3272) of them were up-regulated, and 0.6% (18 of 3272) were down-regulated in the presence of the viruses. Fourteen novel micro-RNA-like RNAs (Cer-milRNAs) were predicted. Gene target prediction of the differentially expressed Cer-milRNAs was quite ambiguous; however, fungal genes involved in transcriptional regulation, catalysis, molecular binding, and metabolic activities such as gene expression, DNA metabolic processes and regulation activities were differentially expressed in the presence of the mycoviruses. [ABSTRACT FROM AUTHOR]

Accurate soil management has long been the focus of research in agroecology. Crop productivity can be enhanced while reducing environmental threats from excessive fertilization by fully comprehending the spatial variability of soil properties and delineating management zones (MZs). A field investigation was carried out at experimental sites outside Hefei City's administrative districts in China to study the spatial variability of soil properties and the delineation of MZs. A total of 9601 soil samples were collected in the study area. A variety of soil properties were analyzed, including the pH, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, slowly released potassium, available sulfur, available boron, available copper, available zinc, available iron, and available manganese. The coefficient of variation for various soil properties exhibited a wide range, spanning from 12.2% to 100.5%. The geostatistical results show that most soil properties have moderate to strong spatial autocorrelation, and the ordinary kriging method is used to map the distribution of soil properties. The principal component analysis method was used to reduce the dimension of 13 soil properties to 4 principal components, and the fuzzy c-means clustering method was used to delineate MZs. The calculation results of the fuzzy performance index and normalized classification entropy show that the optimum number of MZs is five. In the study area, the western part exhibits the highest soil fertility, primarily attributed to its elevated organic matter content. Additionally, organic matter emerges as a key factor influencing sustainable agricultural production in this region. These results form the basis for soil managing areas outside the administrative districts of Hefei City. [ABSTRACT FROM AUTHOR]