Interactive effects of drought stress and chitosan application on physiological characteristics and essential oil yield of Thymus daenensis Celak

作     者：Zohreh Emami Bistgani Seyed Ataollah Siadat Abdolmehdi Bakhshandeh Abdollah Ghasemi Pirbalouti Masoud Hashemi 

作者机构：Ramin Agriculture and Natural Resources University of Khozestan Department of Medicinal Plants Shahrekord Branch Islamic Azad University Stockbridge School of Agriculture University of Massachusetts Amherst Amherst 

出 版 物：《The Crop Journal》 (作物学报（英文版）)

年 卷 期：2017年第5卷第5期

页      面：407-415页

核心收录：

学科分类：0710[理学-生物学] 1008[医学-中药学(可授医学、理学学位)] 0901[农学-作物学] 0902[农学-园艺学] 10[医学] 

基　　金：support from the University of Massachusetts Amherst 

主　　题：Thymus daenensis Chitosan Drought stress Essential oil yield Osmotic adjustment 

摘      要：Thymus daenensis, a perennial herb, is often grown in areas that experience drought conditions during its growing period. Application of chitosan may compensate for the negative impact of drought stress on the yield of oil and secondary metabolites in *** interactive effects of foliar application of chitosan and drought stress on dry matter,essential oil yield, and selected physiological characteristics including photosynthetic pigments, osmotic adjustment, and lipid peroxidation of Thymus were investigated in a two-year study from 2014 to 2015. Treatments consisted of 0, 200, and 400(iL L 1 chitosan applied to plants grown under field capacity, mild drought stress(50% field capacity), and severe drought stress(25% field capacity). Dry matter yield decreased substantially as drought stress intensified. However, essential oil content increased under stress conditions,with the highest essential oil yield obtained from plants under mild drought stress. Foliar application of chitosan compensated to some extent for dry matter and oil yield reduction of plants grown under drought stress. The highest essential oil yield(1.52 g plant-1) was obtained by application of 400 \iL L_1 chitosan under the mild stress condition in 2015 when plants were mature. The compensatory effect of chitosan in reducing the negative impact of stress conditions on dry matter and oil yield was due mainly to stimulation of osmotic adjustment through proline accumulation and reduction of lipid peroxidase level, which increased the integrity of cell membranes of thyme leaves.