Abstract:

The paper aims to study the physiological and biochemical mechanism of fig under drought stress and evaluate the response of fig to drought stress. Taking ‘Browns Wick’ fig as experimental material, the soil water content was set at four levels: conventional water supply (CK, 65%-75% of field capacity), mild drought (LD, 50%-55% of field capacity), severe drought (MD, 40%-45% of field capacity) and extreme drought (ED, 30%-35% of field capacity), effects of different drought stress on fig yield and leaf physical and chemical characteristics were compared. The results showed that the relative water content and chlorophyll content of fig leaves decreased significantly with the increase of stress degree, which reached the minimum value under ED treatment, 35.81% and 44.40% lower than that of CK, respectively. The content of protein, soluble sugar and malondialdehyde (MDA) in leaves increased significantly with the increase of stress degree, and reached the maximum value in ED treatment, which increased by 260%, 120% and 473% respectively compared with that of CK; the contents of free proline (Pro) osmotic adjustment substance in leaves increased significantly; the activities of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) increased significantly with the increase of stress degree. The average single fruit weight was 62.11g, which was 20% higher than that of CK. Under ED treatment, the plot yield was the highest, reaching 13.90kg, 41% higher than that of CK. To sum up, drought stress has a significant impact on fig yield and leaf physiological and biochemical indicators, in a certain range, the stronger the stress, the lower the fig yield; fig itself can respond to environmental conditions by regulating osmotic substances and enzyme activities.

Key words: drought stress, fig, enzyme activity, physiology and biochemistry, yield