Bacillus megaterium bakteriya shtammining bug‘doy o‘simligi fotosintetik pigmentlari miqdoriga ta’siri

Abstract

The effect of Bacillus megaterium solutions (1:1, 1:3, 1:5, 1:7 and 1:9 ratios) on the content of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) and on the Chl a/Chl b and ΣChl/Car ratios was studied in the winter bread wheat cultivar "Asr" at the tillering (22.11.2025), stem elongation (07.03.2026) and heading (09.04.2026) stages in the Boyavut area. The response depended on the growth stage and on the solution ratio. At tillering, the 1:3 ratio increased Chl a to 1.50 mg/g versus 1.27 mg/g in the control (about 18%), exceeding the mean±error range (1.24–1.34 mg/g); Chl b (0.72 mg/g) and carotenoids (0.45 mg/g) showed the same trend. At stem elongation, no positive effect on chlorophylls was observed; only the 1:9 ratio kept Chl a at the control level (1.46 mg/g) and raised carotenoids to 0.48 mg/g (control: 0.34 mg/g). The strongest effect occurred at heading: at 1:7, Chl a, Chl b, ΣChl and Car reached 2.08, 1.53, 3.61 and 0.53 mg/g, i.e. about 34%, 39% and 36% higher chlorophylls and nearly twofold higher carotenoids than the control. Thus, the effect of B. megaterium on pigment content is stage-specific: 1:3 was effective at tillering, 1:7 at heading, and no benefit was found at stem elongation.