Structures And Quantitative Characters Of The Modules In A Clonal Plant Of Hordeum Brevisubulatum In Different Habitats

Hordeum brevisubulatum is a perennial tuft herbaceous species of Gramineae. This species is highly tolerant of high salinization and of considerable economic value. It is suitable to be cultivated in arid and semiarid regions, light and intermediate salinization soil for its better quality. Single clone was sampled by the method of big samples. Seven main conclusions could be obtained from the measurement of age structure and statistical analysis of quantitative character of the modules at the level of clone and module under grazing and harvesting and they were as follow:(1) The seedling banks and tillers all consisted of three age classes under grazing and harvesting at the returning green stage. Meanwhile, the populations all showed stable age structures. At the ripe stage, the tillers consisted of three age classes, and the populations all showed expanding age structures under harvesting, while the tillers consisted of four age classes, and the populations all showed stable age structures under grazing. At the end of growing season, both the seedling banks and the tillers all consisted of three age classes and the populations showed expanding age structures under harvesting, while the seedling banks consisted of four age classes and the populations showed stable age structures and the tillers consisted of three age classes and the populations showed expanding age structures under harvesting.(2) The bud banks of the clones of H. brevisubulatum all consisted of four age classes both at the returning green stage and the ripe stage under grazing and harvesting. At the end of growing season, bud banks consisted of four age classes under grazing and five age classes under harvesting. The number of buds under grazing was more than that under harvesting at the returning green stage and the ripe stage, and the numbers of 1st and 2nd were all extremely dominant. At the end of growing season, the number of buds under harvesting was more than that under grazing.(3) Biomass of the tillers was of expanding age structure of H. brevisubulatum under grazing and harvesting, and the biomass of 1st and 2nd were all extremely dominant, accounting for more than 90%. The devotion of 1st was the most, and the matter accumulation decreased as the age increased. The matter accumulation under grazing and harvesting were 2.3%, and 0.1% at the highest age class, respectively.(4) The biomass of single tiller was the highest in 1st single tiller, and 2nd and 3rd decreased in order. The reproduction capacity decreased as the age increased.(5) Each quantitative character of H. brevisubulatum clone all had big phenotypic plasticity and the number and biomass of each age class increased with the diameter of cluster and the total tillers and increased for both isogony and allometry.(6) There was a significantly positive correlation between the number of winterness tillers and the total number of tillers, between the number of winterness tillers and the number of dormancy modules at the returning green stage and the end of growing season, and there was a significantly positive correlation between the biomass of rhizome and the diameter of cluster, between the biomass of rhizome and the total number of tillers under grazing and harvesting.(7) There was a significantly positive correlation between spike length and spike biomass, between tiller biomass and tiller height, between spike biomass and tiller biomass. There was no significantly correlation between reproductive growth ratio and tiller height at ripe stage under grazing and harvesting.