本文選題：裸果木 + 生態(tài)位模型　； 參考：《內(nèi)蒙古農(nóng)業(yè)大學(xué)》2017年博士論文

【摘要】：裸果木(Gymnocarpos przewalskii Maxim.)為石竹科裸果木屬小半灌木,國家一級保護(hù)植物。古地中海孑遺植物,對中國西部及中亞荒漠的形成、荒漠植被形成歷史的研究具有重要的意義,可開發(fā)利用的重要植物資源。裸果木種群分布呈斑塊狀,分布區(qū)生態(tài)系統(tǒng)脆弱、極端氣候多發(fā)及人為因素的干擾等原因,種群數(shù)量明顯下降。因此探尋氣候變化下種群分布特征與性狀變異特點(diǎn)及適應(yīng)性研究顯得尤為重要。本文基于生態(tài)位模型、解剖學(xué)、生態(tài)化學(xué)計(jì)量學(xué)及分子遺傳學(xué)等方法,探討了裸果木種群適應(yīng)性及不同生境中性狀變異特點(diǎn)。具體研究結(jié)果如下:1.基于Maxent模型預(yù)測裸果木種群隨時(shí)間分布區(qū)變化及影響的主導(dǎo)因子,得出裸果木在末次間冰期分布面積最大,隨著冰期氣候的變遷適宜生境面積逐漸縮小。冰期后隨著氣溫的變暖裸果木分布區(qū)的面積有所增加,目前主要分布于甘肅河西走廊的大部、新疆部分區(qū)域及內(nèi)蒙古和寧夏兩區(qū)中西部。而未來氣候情景下,適宜生境范圍逐漸向甘肅河西走廊地帶收縮,分布區(qū)面積可能逐漸縮小。因祁連山、阿爾金山、昆侖山及賀蘭山山脈的阻擋,冰期在甘肅的河西走廊(疏勒河、黨河流域)、玉門關(guān)西北緣(哈密)、內(nèi)蒙古西部(雅布賴)及新疆(塔里木)等盆地形成了部分的避難區(qū);采用刀切法分析得出影響分布面積變化的決定性因子為年降雨量和最冷季節(jié)溫度。2.對裸果木12個(gè)地理種群分布區(qū)氣候、土壤理化性質(zhì)、植被特征分析,影響裸果木分布區(qū)主要?dú)夂蛞蜃訛槟杲邓�、年均溫及年日照時(shí)數(shù)等。分布區(qū)土壤類型為灰漠土、灰棕漠土及棕漠土;土壤養(yǎng)分含量低,氯離子、硫酸根離子及鈣離子含量較大,土壤為中性或弱堿性。分布區(qū)植物區(qū)系成分中古地中海、西亞至中亞種占優(yōu)勢(48%),北溫帶分布種(24%)和世界分布種(12.8%),溫帶性屬具有絕對優(yōu)勢。以氣候特征、土壤因子特征和群落物種組成對樣地聚類分析發(fā)現(xiàn),引發(fā)裸果木分布區(qū)環(huán)境異質(zhì)性的主要原因?yàn)榻邓康取?.裸果木形態(tài)結(jié)構(gòu)具有較強(qiáng)的干旱適應(yīng)特征。葉片明顯肉質(zhì),葉肉柵欄組織為環(huán)柵型,遠(yuǎn)軸面和近軸面的結(jié)構(gòu)差異明顯;葉肉中央為貯藏組織,細(xì)胞形態(tài)不規(guī)則,體積較大排列松散,部分貯藏細(xì)胞內(nèi)含晶簇;近軸面和遠(yuǎn)軸面柵欄組織發(fā)育程度具有差異;葉脈脈序?yàn)榛銎叫忻},主脈為中心發(fā)育兩個(gè)環(huán)形分布的側(cè)脈束,側(cè)脈束內(nèi)分布貯藏組織,外側(cè)為柵欄組織。不同裸果木種群間形態(tài)、葉表皮和結(jié)構(gòu)的22個(gè)特征指標(biāo)進(jìn)行分析變異系數(shù)為0.1 16～0.185、可塑性指數(shù)為0.298-0.397,分布于甘肅肅北縣及阿克塞縣裸果木變異性及可塑性較大,表明種群適應(yīng)性較強(qiáng)。采用主成分分析和因子聚類法對植株形態(tài)、葉表皮特征及葉結(jié)構(gòu)特征分析結(jié)果推斷,裸果木株高、冠幅、遠(yuǎn)軸面氣孔大小和數(shù)目、微管組織及葉片厚度等特征變化較大;相關(guān)性分析發(fā)現(xiàn)氣候因素的降水量及溫度導(dǎo)致形態(tài)及結(jié)構(gòu)指標(biāo)間差異較大。4.對不同種群裸果木化學(xué)計(jì)量學(xué)特征分析結(jié)果表明,葉C含量變化為319.15～493.98mg·g-1,葉 N 含量變化為 5.41～32.71 mg·-1,葉P含量變化為 0.56～1.36 mg.g-1。種群間化學(xué)計(jì)量特征存在顯著差異,平均值均低于全球陸生植物(1251種)及我國植物(554種)。降水量導(dǎo)致了裸果木高氮、低磷適應(yīng)特點(diǎn);裸果木葉N:P為26.09,葉片受易受磷的限制,而P含量易受溫度限制;裸果木葉C、N、P與土壤的20～40cm 土層相關(guān)性較大,可能養(yǎng)分吸收主要來源該土層。不同種群生態(tài)化學(xué)計(jì)量特征變異為(8.930～15.703),甘肅柳園鎮(zhèn)及肅北縣的裸果木種群變異較高。5.利用ISSR標(biāo)記分析裸果木種群遺傳多樣性結(jié)果表明,在群體內(nèi)標(biāo)記多態(tài)性位點(diǎn)百分率(PPB)為90.01%,Nei's多樣性指數(shù)(He)為0.2488。居群水平上,PPB變化范圍為61.54%～81.12%,平均為67.37%,遺傳多樣性較高。Nei's基因分化系數(shù)(Gst)為0.2790,表明居群間遺傳分化較小,居群內(nèi)存有豐富的遺傳變異。UPGMA法及PCA法的分析結(jié)果表明,裸果木12個(gè)種群可分為4大類群,種群遺傳距離與地理距離有相關(guān)性;溫度、土壤氮含量及全鹽含量等環(huán)境因素對種群遺傳多樣性高低有一定影響。
[Abstract]:Bare fruit trees (Gymnocarpos przewalskii Maxim.) are small shrubs of nude carnara, a national first class shrub, and a national first class protected plant. Ancient Mediterranean relict plants, the formation of desert in Western and Central Asia, are of great significance to the study of the history of desert vegetation. It is particularly important to explore the characteristics and adaptability of population distribution and character variation under climate change. This paper is based on the methods of niche model, anatomy, biological chemometrics and molecular genetics. The adaptability of naked fruit tree population and the characteristics of neutral variation in different habitats were studied. The results were as follows: 1. based on the Maxent model, it was found that the largest distribution area of bare fruit trees in the last interglacial period was the largest, and the suitable habitat area was gradually reduced with the change of the glacial climate. As the temperature is warmer, the area of the bare fruit tree distribution area has increased, which is mainly distributed in the large part of the Gansu Hexi Corridor, the part of Xinjiang and the central and western regions of the two regions of Inner Mongolia and Ningxia. In the future climate scenario, the suitable habitat scope is gradually contracted to the west corridor of Gansu and the area of the distribution area may gradually shrink. As the Qilian Mountains, a The barrier of Mount Jinshan, Kunlun Mountains and Helan mountain range, the glacial period in the Hexi Corridor (Shule River, the party river basin) in Gansu, the northwest edge of the Yumen Pass (Hami), the west of Inner Mongolia (iabrei) and Xinjiang (Tarim) and other basins formed part of the refuge area; the decisive factor affecting the change of the distribution area by the knife cutting method is the annual rainfall and the rainfall. The coldest season temperature.2. affects the climate, soil physicochemical properties and vegetation characteristics of 12 geographical populations in bare fruit trees. The main climatic factors affecting the bare fruit are the annual precipitation, the annual temperature and the annual sunshine hours. The soil types are gray desert soil, gray brown desert soil and brown desert soil, and the soil nutrient content is low, chlorine ion and sulfate ion ion are in the distribution area. And the content of calcium ion is larger, the soil is neutral or weak alkaline. The flora of the area is ancient Mediterranean, Western Asia to middle subspecies is dominant (48%), the north temperate zone (24%) and the world distribution species (12.8%), temperate species have absolute superiority. The main reason for the environmental heterogeneity in the bare fruit tree distribution area is the strong drought adaptation characteristics of the.3. naked fruit trees, such as precipitation. The leaves are obviously fleshy, the leaf palisade is the ring gate, the structure of the distal axis and the paraxial surface is distinct. The central leaf of the leaf is a storage organization, the cell morphology is irregular, the volume is large and loose and partial storage is stored. The growth degree of the palisade in the near axis and the distal axis is different; the vein pulse sequence is based on the parallel vein, the main vein is the central development of two circular distribution side veins, the storage tissue in the side veins is distributed, the outside is the palisade tissue. The 22 characteristics of the different naked tree species, the epidermis and the structure of the leaf are analyzed. The coefficient of variation is 0.116 to 0.185, and the plasticity index is 0.298-0.397. The variation and plasticity of bare fruit trees in Subei County and Axi County of Gansu are large, which indicates that the population is more adaptable. The results of the plant morphology, leaf epidermis and leaf structure characteristics of the plant are deduced by the principal component analysis and factor clustering method. The size and number of the pores and the thickness of the microtubules and the thickness of the leaves were changed greatly. The correlation analysis found that the precipitation and temperature of the climatic factors resulted in the difference between the morphological and structural indexes. The analysis of chemometrics of different species of bare fruit trees by.4. showed that the variation of leaf C content was 319.15 to 493.98mg. G-1, and the content of N in leaves changed. The chemical stoichiometric characteristics of the leaves P content changed from 0.56 to 1.36 mg.g-1. were significantly different. The average values were lower than the global terrestrial plants (1251 species) and the Chinese plants (554 species). The precipitation resulted in the high nitrogen and low phosphorus adaptation of bare fruit trees; the N:P of bare fruit leaves was 26.09, the leaves were susceptible to phosphorus, and the P content was easy. Limited by temperature, C, N, P and 20 ~ 40cm soil layers in the soil were related to the soil layer of 20 ~ 40cm, and the nutrient absorption was mainly derived from the soil layer. The variation of the ecological stoichiometric characteristics of different populations was (8.930 to 15.703). The population variation of bare fruit trees in Gansu Liu Yuan town and Subei County was higher than that of ISSR markers in the analysis of the genetic diversity of bare fruit population. The percentage of polymorphic loci (PPB) in the population was 90.01% and the Nei's diversity index (He) was at the level of 0.2488. population, and the range of PPB was 61.54% to 81.12%, with an average of 67.37%, and the genetic diversity of.Nei's gene differentiation coefficient (Gst) was 0.2790, indicating that the genetic differentiation between populations was smaller and the population had a rich genetic variant.UPGM in the population. The results of A and PCA analysis showed that the 12 species of bare fruit trees could be divided into 4 groups, and the genetic distance of the population was related to the geographical distance, and the environmental factors such as temperature, soil nitrogen content and total salt content had a certain influence on the genetic diversity of the population.

【學(xué)位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：Q948
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本文編號：1889829