caa a22 4500 469097515 CHVBK 20180323133035.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00317246 doi (NATIONALLICENCE)springer-10.1007/BF00317246 Density effects of flowering phenology and mating potential in Nicotiana alata [Elektronische Daten] [Elizabeth Lyons, Thaddeus Mully] Summary: We investigated effects of plant density on floral phenology and potential mating in artificial populations of the outcrossing ornamental Nicotiana alata planted at three densities. Path analysis revealed that increasing plant density yielded significantly earlier peak flowering dates, significantly earlier last flowering dates, and significantly lower plant biomass. Direct effects of density on final flower number were not significant. Variation among replicate plots for first date of flowering was larger than variation among densities, indicating that factors other than density influence floral initiation. We did not record actual mating, but determined from phenological data the number and identity of potential mates. Increased density had several effects on potential mating patterns and on potential Ne, effective population number. At high density, fewer focal plants flowered for shorter durations. This led to less overlap in flowering time among plants, decreasing the number of potential parental combinations possible among the progeny. Two outcomes of high density, the lower total number of plants flowering and the lower number of plants flowering at most census dates, tended to reduce potential Ne. In contrast, it was low density, where variance in flower number was greatest, that was most likely to yield the greatest reduction in Ne due to variance in progeny number. At high density the potential for assortative mating among tall plants was much greater and occurred later than among large plants at low density. Much of the potential high density assortative mating occurred late in the phenology of individual plants, when there was likely to be lower fruit set. We discuss how ecological agents that alter flowering phenology can potentially alter the genetics of populations, the level and timing of assortative mating and, if genetic variation for response to such ecological agents exists, the potential selection regime. Springer-Verlag, 1992 Flowering phenology nationallicence Density effects nationallicence Ne nationallicence Lyons Elizabeth Department of Biology, Amherst College, 01002, Amherst, MA, USA aut Mully Thaddeus Department of Biology, Amherst College, 01002, Amherst, MA, USA aut Oecologia Springer-Verlag 91/1(1992-08-01), 93-100 0029-8549 91:1<93 1992 91 442 https://doi.org/10.1007/BF00317246 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317246 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lyons Elizabeth Department of Biology, Amherst College, 01002, Amherst, MA, USA aut NATIONALLICENCE 700 1- Mully Thaddeus Department of Biology, Amherst College, 01002, Amherst, MA, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 91/1(1992-08-01), 93-100 0029-8549 91:1<93 1992 91 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer