بررسي تاثيرگذاري كود زيستي و ميزان آن بر گياه گوجه¬فرنگي

Solanum lycopersicum , Paenibacillus , Biofertilizer , Hydro‎ponic

Studying the effectiveness of biofertilizer an‎d its amount on tomato plants

زيست شناسي سلولي مولكولي و ميكروبيولوژي

Plants require adequate access to vital nutrients for optimal growth, an‎d limitations resulting from nitrogen (N) an‎d phosphorus (P) deficiency can significantly reduce their performance an‎d health. The use of beneficial rhizosphere bacteria, particularly Paenibacillus strains with the ability to fix atmospheric nitrogen an‎d solubilize insoluble phosphate, as biofertilizers can increase plant access to these elements an‎d reduce the environmental impact of using chemical fertilizers. In this research, the effect of inoculation with Paenibacillus bacteria combined with Hoaglan‎dʹs nutrient solution was investigated on the growth an‎d physiological indices of ʹCanyonʹ tomato (Solanum lycopersicum) plants. First, the strainʹs ability for nitrogen fixation an‎d insoluble phosphate solubilization was confirmed using specific Winogradsky an‎d Sperber media, respectively, an‎d then a suspension was prepared an‎d used for plant treatment. Sterilized seeds an‎d seedlings were planted in a hydro‎ponic substrate consisting of a peat moss an‎d perlite mixture. The treatments consisted of three different levels of Hoaglan‎d nutrient solution concentrations at ratios of (1/"4" ), (1/"8" ) an‎d (1/"12" ), each of which was investigated in two states: with bacterial inoculation an‎d without bacterial inoculation. The indices examined included shoot length, leaf area, relative water content (RWC), electrolyte leakage (EL), an‎d the content of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, an‎d carotenoids). Statistical analysis was performed using two-way analysis of variance (ANOVA) an‎d Duncanʹs multiple range test. The results indicated that inoculation with the Paenibacillus bacterium at all nutrient solution levels (1/"4" , 1/"8" an‎d 1/"12" ) improved the plantʹs growth an‎d physiological indices compared to the non-inoculated treatments. Specifically, shoot length increased by 11.94%, 25.61%, an‎d 28.3% in the inoculated treatments, respectively. Leaf area was also greater by 22.3%, 56.53%, an‎d 56.65%, respectively. Relative water content of the leaf increased by 3.67%, 3.19%, an‎d 4.85% in the same order. In contrast, electrolyte leakage decreased by 40.2% an‎d 29.8% in the (1/"4" ) an‎d (1/"8" ) treatments, respectively. Furthermore, total chlorophyll increased by 15.81%, 25.1%, an‎d 18.51% at the (1/"4" ), (1/"8" ) an‎d (1/"12" ) levels, respectively, an‎d carotenoids increased by 9.67%, 10.94%, an‎d 14.41%, respectively, compared to their corresponding non-inoculated treatments. The highest growth an‎d best physiological indices were related to the (1/"4" ) Hoaglan‎d plus bacteria treatment, an‎d the lowest was related to the (1/"12" ) Hoaglan‎d without bacteria treatment. Overall, Paenibacillus bacteria, as an effective biological agent, can enhance the performance an‎d health of tomato plants under restricted nutritional conditions by improving nutrient uptake an‎d promoting growth an‎d physiological indices. This highlights the importance of using beneficial soil bacteria in the development of biofertilizers an‎d increasing agricultural productivity.

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بهروز صالحي اسكندري

153682