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Pak. J. Bot., 45(SI): 91-96, 2013.

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SCREENING RHIZOBACTERIA CONTAINING ACC-DEAMINASE FOR GROWTH PROMOTION OF WHEAT UNDER WATER STRESS

NAZNEEN BANGASH¹, AZEEM KHALID¹, TARIQ MAHMOOD¹ AND MUHAMMAD TARIQ SIDDIQUE²

Abstract: Due to climate changes globally, rainfall has become more erratic causing water shortages in the rainfed regions, resulting in reasonable yield reduction in cereal crops including wheat. Plant growth is inhibited due to higher levels of ethylene production in the rhizosphere under water stress conditions. Rhizobacteria containing ACC-deaminase can facilitate plant growth to overcome these harmful effects. Isolation of rhizobacteria containing ACC-deaminase from the rhizosphere of wheat grown in different districts of Chakwal, Attock and Rawalpindi, were screened for growth promotion of wheat seedlings under axenic conditions. The results of the laboratory experiments conducted on wheat revealed that some rhizobacterial isolates increased root and shoot growth as compared to the uninoculated control. The selected strains were again tested in soil to assess their effectiveness for improving growth of wheat seedlings under water stress soil conditions. The results revealed that inoculation with selected isolates increased the root length (upto 54.6%), shoot length (up to 80.2%), dry root weight (up to 54.2%) and dry shoot weight (up to 95.4%) of wheat seedlings grown at different water levels (i.e., 60, 45, 30 and 15% water holding capacity, WHC) over uninoculated control.Isolated strains belonging to the genus Serratia and Aerococcus were found to be most effective strains in improving the growth of wheat seedlings in water stress conditions.The results clearly indicate that rhizobacteria isolated from rainfed regions were effective in promoting growth of wheat seedlings under axenic conditions. 

¹Department of Environmental Sciences, PirMehr Ali Shah Arid Agriculture University, Rawalpindi 46300, Pakistan

²Department of Soil Science& Soil Water Conservation, PMAS Arid Agriculture University, Rawalpindi, Pakistan

Corresponding author’s e-mail: nbangash@hec.gov.pk, azeem@uaar.edu.pk