Maize (Zea mays L.) is a globally vital crop for food, feed, and biofuel production, with plant height (PH) being a key agronomic trait that significantly influences yield, lodging resistance, and stress tolerance. This study identified a single-base mutation in the D1 (Dwarf 1) gene responsible for the dwarf phenotype in the maize mutant 16N125. Through genetic analysis and fine mapping, the candidate region was localized to chromosome 3, narrowing it down to an interval containing three genes. Sequencing revealed a non-synonymous mutation in D1, which encodes a gibberellin 3-beta-dioxygenase, leading to amino acid substitutions at positions 61 and 123. Genetic analysis of F2 populations confirmed that the mutation at position 61 was responsible for the dwarf trait. Furthermore, the mutation was detected in several Chinese inbred lines, indicating its potential role in dwarfing under specific conditions. These findings provide critical insights into the genetic mechanisms regulating maize plant height, offering valuable information for breeding programs focused on improving crop architecture and yield to address the challenges of global food security and climate change.

Maize production in Fuxin City, Liaoning Province, China, is threatened by northern corn leaf blight (NCLB) and Fusarium stalk rot, with straw return under conservation tillage exacerbating the NCLB severity by 20% in local fields. This study evaluated the efficacy of combining difenoconazole, a commonly used fungicide, with a Trichoderma bioagent for disease control in straw-incorporated soils. Field trials in Fuxin showed that applying 300 g/ha difenoconazole with 1.5 L/ha Trichoderma fermentate achieved superior results: a 72.4% reduction in the NCLB disease index and a stalk rot incidence of only 0.61%. These outcomes significantly outperformed single-component treatments like difenoconazole alone (56.2% NCLB suppression) or other fungicides (e.g., carbendazim, triadimefon). The combined treatment also outperformed the single treatments with biocontrol agent (67.1% NCLB inhibition). The results highlight the synergistic potential of integrating chemical and biological agents to manage residue-borne diseases, offering a practical strategy for sustainable disease control in conservation agriculture systems with straw return in Liaoning, China.

A comprehensive two-year investigation (2024–2025) was conducted across Northeast China’s crucial grain production base to assess the status of maize diseases. Field surveys spanning three provinces and Inner Mongolia revealed a significant shift in the regional disease profile, with diagnosis performed by experienced personnel based on characteristic field symptoms. The results demonstrated that maize white spot (MWS) has emerged as a severe new threat, recording remarkably high disease severity indices exceeding 80 at multiple locations (e.g., LDD25-1: 86.83). Concurrently, gray leaf spot (GLS) was confirmed as the most prevalent foliar disease, forming stable areas of high severity in the eastern mountainous regions where its disease indices consistently surpassed 60 (e.g., LFS25-1: 65.26), thereby exceeding the impact of northern corn leaf blight. In contrast, stalk rot (SR) maintained a low field incidence rate below 10%, while other diseases such as Curvularia leaf spot and maize eyespot were only observed locally or were absent during the 2025 survey period. These findings underscore the emergence of MWS as a critical threat and affirm the dominant status of GLS, offering a scientific foundation for prioritizing disease management strategies in the region.

The pronounced genetic heterogeneity of Botrytis cinerea confers adaptive advantages in fluctuating environments. Consequently, elucidating the pathogen's population structure within agricultural ecosystems is essential for developing enhanced control strategies. A total of 171 Botrytis isolates were collected from greenhouse-grown tomatoes in Liaoning province, China. Through integrated morphological characterization, restriction fragment length polymorphism analysis of the Bc-hch gene, and multi-locus phylogenetic analysis based on G3PDH, HSP60 and RPB2 sequences, the dominant species responsible for tomato gray mold in Liaoning was identified as B. cinerea. The diversity of B. cinerea isolates was assessed by characterizing transposable elements (TEs) including Boty and Flipper, determining mating types (MAT1-1 and MAT1-2), and conducting morphological and microsatellite (SSR) analyses. Based on TEs profiling, the isolates were classified into three types: Boty, Flipper, and Transposa, accounting for 19.3%, 25.7%, and 55.0% of the population, respectively. The composition of TE types differed significantly among sub-populations. The overall ratio of MAT1-1 to MAT1-2 deviated from 1:1. However, in 13 out of 14 geographic sub-populations, the mating type ratio was consistent with 1:1; only one sub-population exhibited a significant deviation. Genetic diversity was evaluated using nine SSR markers, revealing a high level of polymorphism. Most genetic variation was observed within populations. A moderate level of gene flow was detected among populations, along with a relatively high inbreeding coefficient. Significant genetic differentiation was observed among geographical populations, with the highest diversity found in Anshan and Fuxin, and the lowest in Huludao. Cluster analysis indicated a discernible phylogeographic pattern, suggesting an association between genetic relationship and geographic distance. The findings of this study enhance our understanding of the population structure and genetic diversity of B. cinerea in Liaoning province, providing valuable insights for disease management strategies.