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Book of Abstracts First Legume Society Conference 2013: A Legume Odyssey Novi Sad, Serbia, 9-11 May 2013
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Corolla tube lengths in red clover (Trifolium pratense) cultivars
Tim Vleugels 1 , Isabel Roldán-Ruiz 2 , Joost Baert 1 , Gerda Cnops 2
Plant Sciences Unit – Genetics and Breeding 1 /Growth and Development 2 , Institute for Agricultural and
Fisheries Research, Melle, Belgium
Red clover increases the yield of grass-clover mixtures by its capacity for nitrogen fixation.
Today, red clover is mainly used as silage and as organic nitrogen source in organic agriculture.
Tetraploid red clover cultivars produce more dry matter weight and have an increased disease
resistance compared to diploid cultivars. However, the disadvantage of tetraploid cultivars is their
poor seed yield. One of the proposed causes is a larger corolla tube length which would prevent
most of bumblebees and honeybees from reaching the nectaries. To test this hypothesis we
measured corolla tube length along with the individual seed yield after open pollination in single
genotypes of 5 diploid and 5 tetraploid red clover cultivars. The corolla tube length varied
between cultivars as well as within cultivars. Although there was a significant difference in corolla
tube length between diploid and tetraploid genotypes, seed yield of individual genotypes was not
correlated with the corolla tube length. The selection for smaller corolla tube lengths in
tetraploids will not increase seed yield so other aspects influencing seed yield such as the number
of flower heads, pollen viability, nectar heights need to be analysed.
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