Differentiation Research Of Shoot Apical Meristem Of Leymus Chinensis On Songnen Plain

Leymus chinensis is a perennial grass. In nature, the main production quomodo isvegetative propagation. This paper research on dynamic anatomise study of the apical budmeristem of the rhizome and the shoot apical meristem of the L.chinensis on the SongnenPlains of China by paraffin sectioning, in order to find the differentiation orderliness of theapical bud meristem of the rhizome and the shoot apical meristem of L. chinensis and offer atheoretical guidance to explain the process of L.chinensis sexual reproduction and to enhancethe seed production.The differentiation of young spikelet of L.chinensis could be divided into six stages:Ⅰprimary stage(the period of the leaf primordia differentiation), Ⅱelongationstage( differentiation of rachis primordia), Ⅲsingle ridge stage( bract differentiation phase),Ⅳspikelet differentiation stage, Ⅴpanicle initiation stage, Ⅵheading stage.1,Research on dynamic of anatomise study of the apical bud meristem of the rhizome ofL.chinensis and find that period of flower bud differentiation mostly concentrate on Augustand September, but there is flower bud differentiation of meristem on the apical of shoot fromApril to October. This is the first time to find that the spikelet differentiation of L.chinensiscan happen all through the growing season. This include that L.chinensis blooming did not beaffected by daylength, so if L.chinensis is long-day plant is still to be discussed.The apical cone diameter of primary is 80.54±9.35um, maximum is 111.3um;the apicalcone height is 72.08±11.99um, maximum is 106.3um. The apical cone diameter of elongationstage is 88.62±11.81um, maximum is 129.3um;the apical cone height is 115.21±19.26,maximum is 195.9um. We can conclude that the height of apical cone is obviously bigger thanwidth from primary stage to elongation stage.2,When winterness tillers of L.chinensis that bourgeon in autumn live after October,most of their apical cone have entered single ridge stage, farthing of them have entered thebeginning of spikelet differentiation stage.3,In spring, the apical cones enter spikelet differentiation stage. The apical cones enterthe panicle initiation stage from the end of April to the early of May. The apical cones do notenter panicle initiation stage in the early of June. The tiller whose apical cones enter spikeletdifferentiation stage can tassel.4 , After heading stage, most of the shoot apical cones(about 75.17%) enterdifferentiation stage, but the differentiation stage is different. There are primary stage,elongation stage and single ridge stage at the same time. The apical cone of primary stage is24.83%. The one of elongation stage is 40.69%. The one of single ridge stage is 34.48%. Thelatest stage is single ridge stage. The possible reason is: the Vernalization is not happened;thewinter is coming and the growing season is short;temperature and light result in floweringtransition.The apical cone diameter of primary is 81.66±10.01um, the minimum is 56um and themaximum is 109.2um;the height is 68.21±10.64um, the minimum is 47.4um and themaximum is 89um. The apical cone diameter of elongation stage is 89.13±11.10um, theminimum is 71.3um and maximum is 127.7um;the apical cone height is 117.43±23.58um, theminimum is 76.4um and maximum is 180.5um. The apical cone diameter of single ridge stageis 122.53±25.77um, the minimum is 84.5um and maximum is 208.8um;the apical cone heightis 211.15±69.03um, the minimum is 125.5um and maximum is 505.4um.It is the first time to report the differentiation stage of apical cone. The most apical coneshave changed from vegetative growth to reproductive growth. It can be concluded that thevegetative shoot of L.chinensis is fake.5,It is put forward that the young spike differentiation of L.chinensis is divided intoinvalid young spikelet differentiation and valid young spikelet differentiation. Valid youngspikelet differentiation period: from June to end of July, primary stage;from August toSeptember, primary stage, elongation stage;from end of September to end of October, singleridge stage;from early of April to end of April of next year, spikelet differentiation stage;from early to middle of May, panicle initiation stage;from middle of May to end of June,heading stage.