Crack-entry invasion of wheat roots by Azospirillumbrasilensevia chemical-enzyme treatment: a way facilitating para-nodule formation and forced association for proper crop yield

Badawi H. Mona

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The induction of nodule-like structures referred to para-nodules was assessed due to 2,4-D, IAA and the enzyme mixture of cellulase and pectolyase in presence of PEG treatment of wheat cultivars inoculated with Azospirillumbrasilense. In gnotobiotic model experiment; 9-18 and 6-19 para-nodule plant-1 were produced due to 2,4 D and IAA treatments respectively. Less than 7 para-nodules plant-1were attributed to Azospirllum alone, numbers increased to 26 when the diazotroph was introduced in combination with p-nodule-inducing agents. The cell wall-degrading enzyme mixture with PEG facilitated the crack-entry invasion of the diazotroph in population of > 5x105cfu g-1 root. High rates of C2H2 reductions of > 200 nmoles C2H4 g-1 root hr-1 were estimated for the enzyme mixture-PEG treated plants. The average glutamine synthetase activities of plant leaves were the highest (57.1-86.3 µ mol g-1Fw hr-1) for IAA-Azospirillum treatment. Wheat plants successfully paranodulated in pot experiment when pre-treated with IAA and enzyme mixture and inoculated with Azospirillum in presence of 50 % of recommended N, plant biomass and N yields increased as well. The highest levels of chlorophyll a (2.10 µg g-1Dw), chlorophyll b (2.28) and carotenoids (1.59) were estimated for inoculated plants pre-treated with IAA plus enzyme mixture. In the field trial, as high as > 2.0 kg plot-1 total biological yield was produced by plants initially primed by soaking in water. The superior grain yields of 441.7-571.4 g plot-1 were attributed to Azospirillum inoculation together with IAA and enzyme mixture for 50 % N-supplied plants. Seed priming somewhat raised the grain yield.




International Journal of Advanced Engineering, Management and Science

The International Journal of Advanced Engineering, Management and Science (IJAEMS) is an internat... see more