Influence of nectar volume and sugar content on seed set in lucerne

Abstract

Twenty-four cultivars of lucerne, representing the genetic variation currently grown in Australia, were grown with flood irrigation at the Agricultural Research Centre, Trangie, New South Wales. Soil type was a red-brown earth Dr 2.23. Plants were sampled during peak flowering to determine nectar volume per 100 florets. Seed set was determined by hand collection and threshing of 100 racemes of mature pods per cultivar. Glucose, fructose and sucrose concentrations in the nectar were measured using high pressure liquid chromatographic analysis. NO other sugars were found in the nectar. Seed set was found to be correlated (r = 0.74, P<0.01) with both nectar volume and sucrose concentration.