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【Objective】Due to its comb filter characteristics, Sampled optical Fiber Bragg Grating (SFBG) has attracted wide-spread attention and become a new focus in the research of optical fiber grating technology. The research work on designing optical filters with high channel numbers, flat tops, and narrow pass bands is of great importance in practical situation. Consequently, an Multi-Phase Shift Interpolated Sampling optical Fiber Grating (MPS-ISFBG) filter is proposed.【Methods】ISFBG has a large number of reflection channels and can introduce multiple flat top narrow transmission channels by inserting multi-phase shift. By optimizing the location of the two π phase-shift distributions of the inserted ISFBGs, an optical filters with 41 transmission channels was designed which covers the C-band with a channel interval of 100 GHz. Each channel has a flat-top response, a narrow 3 dB bandwidth (

Phosphorus (P) is essential for all living cells and organisms, and low-P stress is a major factor constraining plant growth and yield worldwide. In plants, P efficiency is a complex quantitative trait involving multiple genes, and the mechanisms underlying P efficiency are largely unknown. Combining linkage analysis, genome-wide and candidate-gene association analyses, and plant transformation, we identified a soybean gene related to P efficiency, determined its favorable haplotypes and developed valuable functional markers. First, six major genomic regions associated with P efficiency were detected by performing genome-wide associations (GWAs) in various environments. A highly significant region located on chromosome 8, qPE8, was identified by both GWAs and linkage mapping and explained 41% of the phenotypic variation. Then, a regional mapping study was performed with 40 surrounding markers in 192 diverse soybean accessions. A strongly associated haplotype (P = 10−7) consisting of the markers Sat_233 and BARC-039899-07603 was identified, and qPE8 was located in a region of approximately 250 kb, which contained a candidate gene GmACP1 that encoded an acid phosphatase. GmACP1 overexpression in soybean hairy roots increased P efficiency by 11–20% relative to the control. A candidate-gene association analysis indicated that six natural GmACP1 polymorphisms explained 33% of the phenotypic variation. The favorable alleles and haplotypes of GmACP1 associated with increased transcript expression correlated with higher enzyme activity. The discovery of the optimal haplotype of GmACP1 will now enable the accurate selection of soybeans with higher P efficiencies and improve our understanding of the molecular mechanisms underlying P efficiency in plants. [ABSTRACT FROM AUTHOR]