Seasonal Variation in Leaf Component Allocation in Normal, Afila, and Afila-tendrilled Acacia Pea Foliage Near-isolines

Abstract

In pea (Pisum sativum L.) the af gene replaces leaflets with tendrils, and the tac gene restores small leaflets to the terminal portion of the tendrils of afaf plants. Normal (AfAf-TacTac), afila (afaf-TacTac), and afila-tendrilled acacia (afaf-tactac) near-isogenic lines in three genetic backgrounds were evaluated for 2 years in two locations to determine allocation of foliage area and weight of foliage components throughout the growing season. The percentage of total leaf area and weight due to stipule, tendril, leaflet, and tac leaflet were measured three times during the growing season in each environment. Highly significant foliage-type effects were detected for the percentage of leaf area and weight due to stipule and tendril at each sampling date. The pea leaf canopy exhibits large fluctuations in area and weight component allocation throughout the growing season. At 28 days after planting, stipules comprised 34%, 76%, and 53% of the total leaf area, and tendrils comprised 6%, 24%, and 13% of the total leaf area in normal, afila, and afila-tendrilled acacia types, respectively. At harvest, stipules composed 43%, 60%, and 53% of the total leaf area and tendrils composed 15%, 40%, and 22% of the total leaf area in normal, afila, and afila-tendrilled acacia types, respectively. Results from this study demonstrate that significant seasonal variation in allocations of foliage area and weight components exists among these three foliage types.