| Abstract Detail
Development and Structure Hodge, John [1], Hu, Hao [2], Shrestha, Nikee [3], Doust, Andrew [4]. The development of the abscission zone in the inflorescence of Cenchrus (Poaceae). All seed plants need ways to disperse their seeds. In most plants, specialized abscission zones form during seed maturation, so that the dispersal unit will be able to detach easily. In grasses, the grass floral unit of the spikelet allows for various strategies for diaspore release that may, rarely, just be the seed itself, or more often the seed dispersed with various other inflorescence structures as well. In Cenchrus (formerly Pennisetum + Cenchrus), the main dispersal unit is the primary branch complex, comprised of a main rachis, many bristles (sterile branchlets), and one to several spikelets. This detaches from the inflorescence axis and is either disperse by wind or by animals. Later on, the fertile spikelet(s) also detach from the primary branch complex. The abscission zone in Cenchrus is unusual amongst the grasses, as it forms very early in development, and consists of a furrow encircling the primary branch complex rachis. In wild species, the furrow appears to be somewhat above the point of insertion of the primary branch and the inflorescence axis, whereas in the domesticated Cenchrus americanus (pearl millet, formerly Pennisetum glaucum), the furrow is very shallow and much closer to the inflorescence axis. The distance of the furrow away from the axis, the amount of lignification around the furrow, and the size of the vascular bundle all appear to influence the easy detachment (shattering ability) of the primary branch complex from the inflorescence axis. Further work (see Shrestha et al. talk XXXX) will focus on mapping the loci responsible for differences in shattering between domesticated and wild Cenchrus in a mapping population created from C. americanus ssp. americanus and C. americanus ssp. violaceum, as well as examining the mechanical properties that allow for more or less ease of shattering. Log in to add this item to your schedule
Related Links: Doust Lab website
1 - Oklahoma State University, Plant Biology, Ecology, and Evolution, PS 301, Stillwater, OK, 74078, USA 2 - Oklahoma State University, Plant Biology, Ecology, and Evolution, Stillwater, OK, 74078, USA 3 - Oklahoma State University, Department of Plant Biology, Ecology and Evolution, 301 Physical Science, Stillwater, OK, 74078, USA 4 - Oklahoma State University, Botany, Ps301, Stillwater, OK, 74078, United States
Keywords: Pearl millet Shattering Abscission Zone Cenchrus domestication Pennisetum Seed Dispersal.
Presentation Type: Oral Paper Session: DS1, Development and Structure I Location: / Date: Tuesday, July 20th, 2021 Time: 11:00 AM(EDT) Number: DS1005 Abstract ID:650 Candidate for Awards:Katherine Esau Award,Developmental and Structural Section Graduate Student Registration Award |