Efficiency of various insects in germplasm regeneration of carrot, onion and turnip rape accessions

Abstract

AbstractSeed regeneration is one of the most important tasks in genebank work. To regenerate germplasm of allogamous, entomophilous plant species in isolation facilities, insects are often used as pollen vectors. The objective of this study was to determine the effect of pollinator species, pollinator densities, pollinator combinations, and flower preferences on the seed quantity and quality of Daucus carota, Allium cepa, and Brassica rapa. The isozyme phosphoglucoisomerase (PGI) served as genetic marker in determining outcrossing rates and pollen dispersal distances. Field plots and isolation cages without insects were used as controls. The pollinators studied consisted of the following insect species from German native fauna: red mason bees (Osmia rufa L.), hoverflies (Eristalis tenax L.), and blowflies (Calliphora sp. and Lucilia sp.). In D. carota and B. rapa, higher seed yields were achieved in isolation cages than in field plots, but in A. cepa lower seed yields were obtained in the isolation cages. Although O. rufa showed no liking for A. cepa, unintentional pollination was effected by this insect in isolation cages. Lower insect densities were necessary for O. rufa than for the various fly species.