| There are 28 species of wild Alliums widely distributed in mountains, forest gaps, shrublands and various types of grassland in Inner Mongolia. Wild alliums cover a wide range of ecological types in terms of water relations and geographical origins. Most of the wild alliums are common companying species in the grassland ecosystems and a few are constructive or dominant species. Most of the alliums are excellent forage plants. Therefore, it was important to study Allium species. Three most commonly found wild Alliums (Allium mongolicum, A.polyrhizum, A.tenuissimum) were investigated for their ecological adaptability, sexual reproduction characteristics, vegetative propagation characteristics and reproductive strategies etc. Main research results were as follows:1. Anatomical structures were observed with paraffin sectioning method. The results showed that all of the three wild plants of Allium.mongolicum, A. polyrhizum and A. tenuissimu. had well developed water storage tissues. They were typical drought resistant succulent plants.2. Comparisons on drought-resistance and heat-risistance of the three plants were studied using seedlings in the aspects of seedling morphological characters, cell membrane permeability, proline contents etc. The results show: water content of leaves was high; Proline content increased dramatically under drought stress during the first 4ds, then gradually declined; cell membrane permeability of Allium mongolicum and A.polyrhizum was relatively stable under streess, but increased obviously in A.tenuissimum. Under 30℃and 35℃temperature for 6d, dehydration on leaves was observed, but not fetal. Under 40℃for 6d, 50% seedlings of Allium mongolicum and A.polyrhizum was dried up. Half-lethal high temperatures for the cell survival are different in the three plants:A.polyrhizum 75.58℃, A. mongolicum 61.13℃, A.tenuissimum 38.58℃. In summary, A.polyrhizum has the strongest heat resistance, followed by A. mongolicum. and A.tenuissimum had the lest.3.The breeding system of the three wild Aillium species were studied from the aspects of pollen viability, stigma receptivity, ratio of pollen/ovule ((P/O)), hybrid index (OCI), seed-setting rate by artificial pollination, insect visit etc. Results showed: The three plants had high pollen viabilities and fertililization rates. The pollen life was about 8h. Best pollination time was 3-4h after flowering. All the three plants had high stigma receptivity. Pollination duration could last for about 5ds, best pollination time was about 2ds after flowering.The breeding systems of A. mongolicum and A.polyrhizum were cross-pollinated, a few were self-compatible. A.tenuissimum generally belonged to self-crossed, occasionaly, cross-pollination occured.4.Analyses on seed yield components of the three wild Alliums showed that actual seed yield were high, reaching 16443.14kg/hm2(A. mongolicum). The lowest yield was 1902.07kg/hm2(A.polyrhizum). Actual yields accounted for more than 30% of the potential seed yields.5. Germination characteristics of the new seeds (stored for one month) and the old seeds (stored for more than 7 months) on the three wild Allium was studied. Results showed: Seed water absorptions of all the three plants were small(60%～77% of the seed dry weight. Imbibition was fast(26h～34h). All the three plants showed transient dormancies.The seeds of A. mongolicum and A.tenuissimum showed combined type of dormancy of micropyle restraining and embryo postmaturation. Seeds of A.polyrhizumbelonged to enforced dormancy of micropyle restrain. Seeds germinations were inhibited by light. Range of germinating temperature is narrow for all the three plants. Seed germination for burial depth and soil moisture content varied in the three plants: A. mongolicum was the most stringent, followed by A.polyrhizum, A.tenuissimum was the least.6. Studies on soil seed bank characteristics showed that the amount of germinatible seeds in the seed bank was high (112.00±46.19～304.00±101.61 m-2). Amount of viable seeds decreased with the increasing soil depth.. Under the natural conditions few seedlings were found. With irrigation, more seedlings were found.
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