Phenotypic Plasticity Of Modules Of Puccinellia Tenuiflora Clones In Alkalized Grassland In The Songnen Plains Of China

Puccinellia tenuiflora is a perennial tuft herbaceous species of Gramineae. This species is highly tolerant of salinization, and it is of considerable economic value, which is a ideal species for the construction of artificial grass and biological management and improvement of saline-alkalized grassland. In this paper, large samples of single independent tuft clones of P. tenuiflora population were sampled, and the relationship between quantity characters of clone modules and cloze sizes, and between total number of tillers and total biomass were quantitatively analyzed at three development stages, heading stage, flowering stage and ripe stage during two years's period from 2007 to 2008 to provide scientific accumulation for enriching clonal plant population in alkalized meadow in the Songnen Plains of China.The results showed that:(1) Clone modules of P. tenuiflora were consist of vegetative tillers, reproductive tillers. Clone modules of P. tenuiflora all had big phenotypic plasticity, and the numbers of reproductive tillers were higher that the ones of vegetative tillers at three development stages, heading stage, flowering stage and ripe stage during two years. Biomasses of vegetative tillers at heading stage and flowering stage in 2008 were higher the ones in 2007, while lower than the ones at ripe stage in 2008. Stem biomass of reproductive tillers decreased first and then increased in 2007,while increased first and then decreased in 2008, and tassel ratio of P. tenuiflora clones in 2007 was higher than the one in 2008.(2) The numbers of reproductive tillers of P. tenuiflora clones increased linearly with the diameters of clusters increasing, and five samples reached significant levels except the samples at ripe stages in 2007, and increasing rates'b'of reproductive tillers at three development stages gradually increased in 2007, and decreased first and then increased in 2008. Total numbers of tillers of P. tenuiflora clones increased exponentially with the diameters of clusters increasing, and five samples reached significant levels except the samples at ripe stages in 2007, and increasing rates'b'of the number of total tillers at three development stages in two years all decreased first and then increased.(3) There was a regular change between biomasses of modules and clusters in two years at different developments. Biomasses of reproductive tillers of P. tenuiflora clones increased linearly with the diameters of clusters increasing, and samples reached significant levels at different development stages both in 2007 and 2008, and increasing rates'b'of biomass of reproduction tillers decreased first and then increased in 2007, and increased first and then decreased in 2008. Total biomasses of tillers increased exponentially with the diameters of clusters increasing, and six samples all reached significant levels, and increasing rates'b'of reproductive tillers at three development stages in two years decreased first and then increased. Total numbers of tillers of P. tenuiflora clones increased exponentially with the diameters of clusters increasing, and five samples reached significant levels except the samples at ripe stages in 2007, and increasing rates'b'of biomasses of total tillers gradually decreased with the growth of clones at different development stages in two years.(4) The numbers of the modules and the total number of tillers of P. tenuiflora clones all had big phenotypic plasticity. The number of vegetative tillers and total numbers of tillers increased exponentially at different development stages both in 2007 and 2008. The numbers of reproductive tillers and total number of tillers increased linearly at different development stages in two years.(5) Biomass of the clone modules and total biomass of P. tenuiflora clones all had big phenotypic plasticity at different development stages in two years. Biomass of vegetative tiller, reproductive tillers and total biomass all increased linearly. Increasing rates'b'of biomass of vegetative tillers gradually decreased from heading stage to ripe stage in two years. Increasing rates'b'of biomass of reproductive tillers gradually decreased in 2007, and decreased first and then increased in 2008.