The development of dominance amongst shoots arising from fragments of Agropyron repens rhizomes

Abstract

Summary: Résumé: Zusammenfassung Fragments of Agropyron repens rhizomes, two lo fifteen nodes long and without u apex, were grown on moist chromato‐graphic paper in Perspex boxes to observe the pattern of shoot growth. A majority of shoots started into growth after decapitation of the rhizome and the smaller the fragment the greater the proportion that grew. After only a day or two, shoots began to cease growth, starling with those furthest away from the shoot that ultimately became the absolute dominant and progressing in order towards it. The shorter the rhizome fragment the quicker absolute dominance MM achieved. Most of the fragments tested had absolute dominants by the twentieth day. The dominant shoot was OMM frequently at the second node from the apical end. Roots grew from the base of new shoots, but did not necessarily cease growth when their shoots ceased growth and even small buds that made no detectable growth at all produced vigorous roots. Three rhizomes that ceased growth altogether before 20 days made more growth after being given potassium nitrate, but it did not apparently prevent the onset of a dominance system. The significance of these results is discussed. Le développement de la dominance parmi les tiges issues de fragments de rhizomes d'Agropyron repens Des fragments de rhizomes d’Agropyron repens comprenant de 2 a 15 noeuds et dépourvus d'apex ont été mis en culture sur papier chromatographique humide dans des boites “Perspex” afin d'observer les modalités de croissance des tiges. La majorité de ces tiges commencérent k croître aprés la décapitation du rhizome et ceci dans une proportion d’autant plus grande que les fragments étaient plus petits. Aprés seulement un jour ou deux, la croissance des tiges commença à se ralentir à partir de celles qui se trouvaient le plus loin de la tige qui devait devenir ultérieurement la dominante absolue et progressérent dans I'ordre, dans sa direction. Plus le fragment de rhizome était petit, plus l'achévement de la dominance absolue fut rapide. La plupart des fragments mis en culture manifestérent des dominances absolues vers le vingtiéme jour. La tige dominante fut le plus fréquemment situtée au second noeud à partir de l'extrémilé apicale. Des racines poussérent à la base des nouvelles tiges, mais leur croissance ne fut pas nécessairement interrompue quand celle des tiges cessa; il arriva même que des bourgeons n'ayant manifeste aucune croissance produisirent néanmoins des racines vigoureuses. Trois rhizomes dont la croissance s'arrêta complétement avant vingt jours se remirent à pousser aprés avoir reçu du nitrate de potassium, mais. apparemment, ceci ne prévint pus le départ d'un systéme de dominance. La signification de ces résultats est discutée. Die Bildung der Dominanz beim Austrieb der Rhizomstücke von Agropyron repens Rhizomstücke von Agropyron repens, 2–15 Nodien lang und ohne Apex, wurden auf feuchtem Chromatographiepapier in “Perspex”‐BehSltern angezogen, um das Sprosswachstum zu beobachten. Nach dem Abtrennen des Rhizomes begannen die meis...

Yarrow: Numbers of buds in the soil and their activity on rhizome fragments of varying length

“…The re-imposition of apical dominance in multinode couch rhizome fragments has been described by Chancellor (1974), and a similar mechanism is probably responsible for the decrease in bud activity with increase in length of rhizome fragments in creeping fog (Holcus mollis) and red top (Agrostis gigantea) (Hakansson & Wallgren 1976).…”

Some aspects of the physiology of the rhizomes of Poa pratensis L.

“…It has received most study in the North American continent where it is an important pasture species (Harrison, 1934;Etter, 1951Etter, , 1953Moser, Anderson & Miller, 1968). It is an interesting species because of its apparent physiological similarities to Agropyron repens (L.) Beauv., a much-studied weed (Palmer & Sagar, 1963;Mc-Intyre, 1965Chancellor, 1968Chancellor, , 1974Leakey, Chancellor & Vince, 1972). Fisher (1965) has described three types of geotropic responses by the rhizomes of P. pratensis where morphological changes are associated with plagiotropic, diageotropic and negatively orthogeotropic phases.…”

Influence of Date and Method of Metribuzin Application for Quackgrass Control in Alfalfa1

“…Quackgrass infestation generally increases with time for established alfalfa stands. The extensive rhizome system of quackgrass maintains a high level of carbohydrate throughout the year (2). This enables quackgrass to resprout after mowing and to gradually become a substantial component of the sward.…”