Primula flowers are heteromorphic with individual plants producing either pin-form or thrum-form flowers. We have used scanning electron microscopy to observe early development of wild-type flowers of primrose (Primula vulgaris), cowslip (P. veris), and the polyanthus hybrid (P. · tommasinii · P. vulgaris). Floral ontogeny in Primula is different from that observed in the well-studied models Antirrhinum majus and Arabidopsis thaliana and our studies reveal morphological landmark events that define the sequence of early floral development in Primula into specific stages. Pinform and thrum-form flowers are indistinguishable during early development with differentiation of the two floral morphs occurring beyond the differentiation of floral organs. Early ontogeny of flowers with homeotic mutant phenotypes was also studied to determine the timing of developmental reprogramming in these mutants. Phenotypes studied included Hose in Hose and Jack in the Green that develop petaloid sepals and leafy sepals, respectively, and Jackanapes plants that carry both these dominant mutations. Recessive double and semi-double flowers that produce additional whorls of petals and/or stamens in place of carpels were also studied. We describe a previously undocumented recessive Primula mutant phenotype, sepaloid, that produces sepals in place of petals and stamens, and a new nonhomeotic, dominant mutant phenotype Split Perianth, in which sepals and petals fail to fuse to form the typical calyx and corolla structures. The molecular basis of these mutant phenotypes in relation to the ABC model is discussed.

The Foot and Mouth Disease (FMD) epidemic of 2001 clearly illustrated the fragility of the UK's farm animal genetic resources. In particular, millions of sheep were killed by the disease and by the ‘stamping out’ policy chosen for disease control. Loss of genetic resources was not evenly spread throughout the UK, nor throughout the many different sheep breeds that are native to the UK and for which the UK has a formal responsibility for protection to the United Nations. In fact, the FMD epidemic demonstrated for the first time that sheep breeds comprising large numbers of individuals which are commercially farmed, can nevertheless be at considerable risk of extinction. The breeds most affected were those restricted to geographical regions of the UK into which the FMD spread. These regionally important breeds are adapted to their particular regional environments, represent an important living heritage for the UK and are a key component in sustaining the rural economies of sheep farming communities.The events of 2001 provided clear proof that there are two components of the UK's farm animal genetic resources demanding protection. One component is already recognised as a priority and is composed of the numerically rare breeds of all domesticated species: these are already under the protection of the Rare Breeds Survival Trust (RBST). The second component has not previously been recognised as a priority for protection. The FMD crisis proved that sheep breeds could exist as large numbers of individuals, but nevertheless face extinction due to their regional location. Urgent attention must be focussed on our Heritage Breeds of sheep. The UK has one of the greatest number of native sheep breeds of any country in the world. The Heritage Breeds provide potentially valuable genetic resources for environmental, low-input farming systems.Heritage GeneBank was founded during the FMD epidemic specifically to protect sheep breeds at threat of extinction from the disease. A group of academic research scientists established a genetic salvage programme: collecting semen and embryos for protection in a gene bank. Germplasm from seven breeds is in long-term storage. Following the crisis, the scientists involved in the gene bank made a commitment to continue their conservation work in recognition that the Heritage Breeds of sheep in the UK continue to require protection.This paper describes: (1) the work of Heritage GeneBank (HGB); (2) the threefold mission of The Sheep Trust, the new national charity that evolved from HGB (http://www.thesheeptrust.org); and (3) the ongoing urgent need for conservation of the UK's Heritage Breeds of sheep threatened by genetic erosion.