Flatpea crossing methods and germplasm screening for reduced 2,4-diaminobutyric acid composition

Abstract

Flatpea (Lathyrus sylvestris L.) is a potentially valuable forage legume, but it contains high levels of 2,4-diaminobutyric acid (A2bu), a compound that can have adverse effects on some animals, including rats and poultry. This study evaluated intercrossed pollination methodology needed for cultivar improvement and characterized intercrossed progeny for A2bu concentration. Pollen germination on an artificial medium, using pollen collected during different stages of flower development, was used to identify appropriate stages for flower emasculation. Pollen dehiscence occurred at an early-bud stage when petal color was first evident. Slightly more mature buds contained pollen with substantially higher in vitro germination than pollen from early-bud stage flowers. Lines that produced high numbers of seeds per pollination were identified from crosses between flatpea accessions. Cross-pollination resulted in significantly higher seed set than selfing. Pollination using caged honeybees was the most efficient method of hybridization, although the degree of inbreeding in bee-pollinated plants could not be determined. Intercrossed progeny produced by honeybee pollination contained a lower mean concentration of foliar A2bu than the mean for flatpea accessions.