Distance Between Pollen Donor and Recipient Influences Fruiting Success in Slickspot Peppergrass, Lepidium Papilliferum

摘要: Plant populations are often spatially structured owing to limited dispersal of pollen and seed. Mating be- tween neighboring individuals in such leads reduced reproductive performance relative matings between distant individuals. This response, which may be a result inbreeding depression or prezygotic mating barri- ers, was investigated for slickspot peppergrass, Lepidium papilliferum L. (Brassicaceae), rare insect-pollinated mustard endemic sagebrush-steppe habitat southwestern Idaho. Through hand pollination experiments we found that indi- vidual plants receiving from sources (75-100 m 6.5-20 km away) had significantly higher percent fruit sets than those relying on (<1 away). Self pollinated produced little no fruit. These results suggest relies primarily, if not exclusively, outcrossed pollination, its structured. Conservation efforts should therefore strive protect sufficiently large areas suitable ensure maintenance genetic diversity preserve enhance connectivity populations. Resume : A structure spatiale des vegetales est souvent liee une dispersion limitee du et grai- nes. Dans de telles populations, le croisement entre individus contigus conduit performances repro- duction reduites, comparativement celles qui proviennent croisements eloignes. Cette reaction pourrait resulter d'une faiblesse consanguinite ou barrieres pre-zygotiques; les auteurs ont etudie cette question chez la lepidie papillee (Lepidium L., Brassicaceae), espece moutarde, endemique aux habitats steppe armoise sud-ouest l'Idaho. Suite pollinisations manuelles, trouve que plantes individuelles recevant distantes (eloignees 75-100 6,5-20 km), montrent un pourcentage mise significativement plus eleve, dependent voisines m). Les auto-fecondees produisent peu pas fruits. Ces resultats suggerent s'appuie surtout, sinon exclusivement, sur pollinisation exterieure, sa population spatialement structuree. conservation devraient chercher proteger aires suffisamment vastes d'habitat approprie pour garan- tir maintien diversite genetique, assurer promouvoir connectivite Mots cles Brassicaceae, auto-fecondation, fecondation croisee, rare. (Traduit par Redaction) Robertson Ulappa 1710