Early frost reactions of different populations of hazelnut (Corylus avellana L.)

Abstract

In Germany, planting of trees and shrubs in an open landscape is regulated by law (Federal Nature Conservation Act §40) because of supposed genetic differences and regional adaptations to habitat conditions (mainly climatic and soil). Therefore, for trees and shrubs to be planted in the open landscape, Germany is divided into six officially designated regions of origin, often referred to as provenances. Propagation and use of plants must be carried out according to these provenances. To evaluate whether plants from different populations differ in their physiological and biochemical reactions, two years old cuttings of Corylus avellana from four populations with different climatic and soil conditions were evaluated in an early frost experiment under controlled conditions. Relative electrolyte leakage as a measure of damage due to frost increased with decreasing temperatures. Selected biomarkers (glucose, fructose, sucrose, starch and proline) were used to assess biochemical reactions of these populations. Increases due to frost were small and in most cases reflected the ranking of the unstressed plants of the populations. Only few statistical differences were found. There were no clear, consistent trends in spite of varied climatic conditions and geographical distance between the populations. Plants from all populations survived frost until -27°C. Hence there are no severe risks in populations' transfer within these latitude and altitude margins with regards to early frost.