【作者】 赵金花；

【导师】 李青丰；

【作者基本信息】 内蒙古农业大学 ， 草业科学， 2010， 博士

【摘要】 内蒙古境内有28种野生葱属植物,其水分生态类群多样,植物区系地理成分也多,广泛分布于山地、林缘、林下灌丛及各类草原,多数以常见成分和伴生成分出现,少数可成为建群种或优势种。其多数种类为各种牲畜喜食的优良牧草。因此葱属植物在内蒙古地区具有一定的代表性。本研究选择其内蒙古草原上最常见的三种野生葱属植物蒙古韭(Allium mongolicum)、碱韭(A.polyrhizum)和细叶韭(A.tenuissimum)为研究对象,对其生态适应性及有性生殖特性、无性繁殖特性和繁殖对策等方面进行系统的对比研究。为野生葱属植物资源保护及植被恢复提供理论依据。研究结果如下:1.通过常规石蜡切片法和徒手切片法进行了形态结构观察,结果表明:蒙古韭、碱韭和细叶韭的根和叶的储水组织较发达,属于多浆类忍耐型旱生植物。2.通过幼苗形态、细胞膜透性、脯氨酸含量等形态和生理指标测定方法进行了三种野生葱属植物幼苗的抗旱性和耐热性比较研究,结果表明:三种野生葱属植物的叶片含水量高;游离脯氨酸含量,在干旱胁迫4d时间内急剧增加,随后逐渐下降;干旱胁迫下,蒙古韭和碱韭的细胞膜透性相对稳定,细叶韭的细胞膜透性逐渐增大。30℃和35℃下高温胁迫6d,只是叶片脱水,无致命的伤害。40℃高温胁迫6d时,最多只有50%(蒙古韭和细叶韭)的幼苗地上部分全干枯,并失去活力。细胞半致死温度分别为碱韭75.58℃,蒙古韭61.13℃,细叶韭38.58℃。综合以上分析,碱韭幼苗抗性最强,蒙古韭次之,细叶韭最弱。3.从花粉活力、柱头可授性、花粉/胚珠比(P/O)、杂交指数(OCI)、人工授粉的结实率、访花昆虫的观察等多方面研究其繁育系统,结果表明:三种野生葱属植物的花粉活力和可育率均较高,花粉寿命约为8h左右,最佳传粉期为开花后3-4h。三者的柱头均具较高的可授性,可授性持续5d左右,最佳授粉期为2d左右。蒙古韭和碱韭的繁育系统为异交,部分自交亲和,需要传粉者;细叶韭为自交为主,有时需要传粉者。4.通过种子产量构成因子的测定分析其种子生产特性,结果表明:三种野生葱属植物实际种子产量最高可达16443.14kg/hm2(蒙古韭),最低1902.07kg/hm2(碱韭),占潜在种子产量比均在30%以上。即三种野生葱属植种子生产能力均较高。5.新种子(存放一个月)和旧种子(存放7个月以上)的萌发特性研究结果表明:三种野生葱属植物种子的吸水量较小(60%～77%种子干重)。种子吸胀速度较快(26h～34h)。三种植物的种子均有短暂的休眠,其中蒙古韭和细叶韭种子为种孔抑制和胚后熟的综合型休眠,碱韭为种孔抑制的强迫型休眠。种子萌发均属于嫌光型,萌发温度范围较窄。种子萌发对埋深和土壤水分含量的要求不同:蒙古韭最严格,碱韭次之,细叶韭要求最广泛。6.采用筛选法和萌发法统计土壤中的种子数量及垂直分布格局,并结合观察幼苗更新得出以下结论:三种野生葱属植物有效种子在土壤中的含量较多(112.00±46.19～304.00±101.61粒/m2)。种子的分布随着土层的加深而减少。自然情况下,实生苗更新数量极少,浇水处理使实生苗更新极显著增加。更多还原

【Abstract】 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.更多还原