Studies on morphological and physiological response of eight blueberry cultivars under water stress

Morphological and physiological responses of lowbush ('Blomidon'), half-high ('Northcountry', 'Northland', 'Northblue', and 'St. Cloud') and highbush ('Bluecrop', 'Duke', and 'Elliott') blueberry cultivars under different water stress treatments as well as the response indicators after relieving the stress with watering treatment in 2009 at Jilin Agricultural University were studied. The results showed that the drought resistance of the cultivars was in the order of 'Northland' > 'Northblue' > 'Northcountry' > 'St. Cloud' > 'Bluecrop' > 'Duke' > 'Elliott' > 'Blomidon'. Proline content of the cultivars at different stage and different water stress treatments were compared and the results showed that the proline (Pro) content increased dramatically under different water stress treatments from July to August in 2009. Pro content decreased after relieving the stress with watering. The superoxide dismutase (SOD) activity values of the cultivars increased at the first stage and then decreased under different water stress treatments. 'Northland' and 'Northcountry' showed the strongest ability, and 'Blomidon' the weakest ability to tolerate drought among the tested cultivars.