Effects of prolonged cold storage on carbohydrate and protein content and field performance of white spruce bareroot seedlings

Abstract

Three-year-old bareroot white spruce (Piceaglauca (Moench) Voss) seedlings from three seedlots were either lifted in the fall of 1990 and stored over winter at −2 °C, or lifted in the spring of 1991. The soluble sugar, starch, and protein contents of needles, stems, and roots were measured in fall-lifted seedlings before, during, and at the end of cold storage and compared with those in spring-lifted seedlings 10 days before outplanting. The soluble sugar content of the seedlings decreased significantly in all tissues during cold storage. At the time of spring planting, sugar and protein levels were similar in fall- and spring-lifted seedlings, but starch content was about two times higher in spring-lifted seedlings. After outplanting, spring-lifted seedlings flushed and resumed root growth sooner than the fall-lifted, cold-stored seedlings. Spring-lifted seedlings also had initially higher photosynthetic rates and water potentials compared with the fall-lifted seedlings. However, both types of seedlings had similar survival rates and 1st year shoot growth in the field. The responses of seedlings to cold storage were similar among seed lots.