Concentration and distribution of total soluble protein in fresh and stored potato tubers
E. Ortiz-Medina, D.J. Donnelly
ISHS Acta Horticulturae 619:323-328.
2003
บทคัดย่อ
Concentration and distribution of total soluble protein in fresh and stored potato tubers
Total soluble protein (TSP) concentration and distribution was determined for 20 cultivars (cvs.) of both fresh and stored potato tubers from the 2000 and 2001 growing seasons. A subset of 7 cvs.was used to compare the concentration and distribution of TSP between fresh field-grown tubers and microtubers. TSP concentration was quantified separately in three tissue layers (periderm, cortex and pith) using the Bradford method. In most cvs., the TSP concentration on a dry weight (DW) basis was greater in the periderm compared with the cortex and pith. The TSP concentration in fresh field-grown tubers ranged from 38 to 73 mg g-1 DW in the periderm compared with 30 to 49 mg g-1 DW in the cortex and pith. After 6 months of tuber storage, the TSP concentration was unchanged in eleven cvs., decreased (mean of 16%) in five cvs. and increased (mean of 18%) in four cvs. While the relative TSP concentration in the tissues tended to be distributed in a similar pattern for each cv., whether fresh or stored, concentrations were greater in microtubers than in fresh field-grown tubers; possibly a function of the readily available nitrogen in the tissue culture medium. These results suggest avenues for identifying and selecting genotypes with increased protein concentrations and improved nutritive value.