Study On Cold Resistance Of Blueberry Flower Buds During The Dormant Period

The study of the cold resistance of blueberry which is studied by the flower buds at the one-year-old dormant branches.The tested varieties are ‘Duke' of north high,‘Northland' of the half-high and ‘Blomidon' of lowbush.It is measured about of the changes of electrolyte exudation,soluble sugar,soluble protein,proline content and peroxidase(POD)activity by the way of artificial cooling between-15? to-40?.The results sh owed that:1.With the decrease of temperature,the electrolyte perme-ability increased.In low t emperature stress,the rate of electrolyte leakage ‘Blomidon' is significantly lower than t hat of 'Northland' and 'Duke',while 'Northland' and 'Duke' are not significantly different.The semi lethal temperatures of flower buds of ‘Northland',‘Duke' and ‘Blomidon' is-21.31?,-22.42? and-23.91? respectively.2.With the decrease of temperature,the change of soluble sugar content was: ‘Blomidon' shows a trend of rising first and then descending.'Duke' and 'Northland' overall show a rising trend.Soluble protein content shows a trend of rise-decrease-rise.Proline content shows a trend of falling-rising-falling-rising.The activity of POD increases first and then decreases.3.According to the membership function,the cold resistance of blueberry flower bud s can be judged as ‘Blomidon','Duke' and 'Northland'.