Quantitatively determined self-incompatibility : 2. Outcrossing inBorago officinaux.
It has been claimed that Borage (Borago officInalis L.) has a multifactorial self-incompatibility system. Such systems may have a high level of ineffective pollination, and we show that this is the case in borage. The ranking of seed set from highest to lowest is as follows: bee-pollination; natural pollination in the absence of bees; artificial cross-pollination between unrelated plants; artificial cross-pollination between related plants; artificial self-pollination. In diallel crosses, significant parental effects were detected but no consistent patterns of seed set, which suggest a simple self-incompatibility system, were detected. The level of outcrossing with natural pollination was very variable but greater than 50%. Thus, there appears to be no straightforward self-incompatibility system in borage.
Genetics Department, The University of Adelaide, 5000, North Terrace, Adelaide, Australia.
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