Directional and correlated effects of selection on amylase activity, weight and developmental time in Tribolium confusum (Coleoptera, Tenebrionidae)

Abstract

The interrelationships of amylase activity, weight and developmental time in a strain of Tribolium confusum were studied by selecting, in turn, for one of these traits and monitoring other, non-target characters, in all lines.Experimental lines were selected for high and low amylase activity (AH, AL), for heavy and light adult weight (WH, WL) and for fast and slow development (DF, DS). The variables monitored every generation in all lines were mean amylase activity (measured colorimetrically), mean individual adult weight, median egg-to-pupa developmental time, mean productivity (offspring per fertile pair) and % sterile pairs.The six lines may be grouped by their response to selection in a meaningful way. AH, WH, and DS all had higher amylase activity, heavier adult weight, slower development and lower fitness (lower productivity, higher percent sterility) than the corresponding AL, WL, and DF, although a different variable was under selection in each pair of lines. These results demonstrate that amylase activity, developmental time and individual weight are intercorrelated.

The process of adaptation of flour beetles to new environments

“…Amylase activity was measured colorimetrically in homogenates of at least ten individual beeties per population every generation. We used the dinitrosalicylic acid (DNS) reagent (Bernfeld, 1955) which was used in previous studies with Tribolium in our laboratory (Wool & Noiman, 1980;Wool & Shirtz, 1984;Wool, 1984;Wool, Namir & Bergerson, 1986). As in the previous work, colorimeter readings were converted to amylase units by running control samples containing known concentrations of mal-5 tose instead of the homogenate.…”