Some burning questions for lucerne breeders
2008
Annicchiarico, P., Centro di Ricerca per le Produzioni Forraggere e Lattiero-Casearia, Lody (Italy) | Scotti, C., Centro di Ricerca per le Produzioni Forraggere e Lattiero-Casearia, Lody (Italy)
Lucerne has displayed a low rate of genetic gain for forage yield compared with other species owning to several biological characteristics which hinder the breeding work (autotetraploidy; open pollination; high gene interaction; perennial growth cycle; high genotype x environment interaction). Without any claim to be exhaustive, we point out some burning questions which we feel as crucial in our selection work. Which is the most cost-efficient selection scheme? A number of schemes have been proposed for Lucerne to cope with its characteristics, but empirical comparisons have been rare and limited to just a few schemes whereas theoretical comparisons are hindered by the absence of reliable estimation for relevant genetic parameters. How exploiting heterosis? Non additive genetic variation, which is the basis of heterosis, could be exploited by free hybrids, in which both hybrid seed and non-hybrid seed are present. Can we breed very drought-tolerant varieties? This issue, of increasing interest in several regions as a consequence of climate change, has been little investigated in terms of genetic variation and underlying physiological mechanisms. How to improve forage quality? Early mowing has a major impact on forage quality, but requires varieties which tolerate frequent cutting. Which opportunities for marker-assisted selection? Various linkage maps for tetraploid Lucerne are available now, but results from US trial suggest that useful markers for forage yield are markedly site-specific and little consistent across cropping years. How to exploit genetic tools from M. truncatula in Lucerne breeding? Markers currently available for Lucerne have essentially been developed for M. truncatula.
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