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高寒植物对低温和强UV-B辐射胁迫响应的分子机制研究
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摘要
针对目前川西北草原面临严重退化甚至沙化的威胁,在川西北高原沙地(丘)进行了植被恢复试验,建立了多种重建模式,对构建群落的分析表明:群落物种多样性随均匀度增加而减小,二者呈极显著负相关,相关系数0.94,线性回归Y=—0.14x+0.75;物种多样性随丰富度增加而增加增大,二者呈显著正相关,相关系数0.85,线性回归Y=0.17x—0.15。在所有重建模式中,T_(10)群落(川草2号老芒麦+无芒雀麦+沙生冰草+多花黑麦草)稳定性最强;T_(13)群落(垂穗披碱草+多花黑麦草+紫羊茅+沙生冰草)竞争性最强。在所有供试物种中群落优势度最大的3个种分别是川草2号老芒麦、垂穗披碱草和沙生冰草。
     在人工构建群落内,入侵最强的2个原生种是赖草和沙生苔草,为进一步开展与原生物种相结合的植被复建模式探讨,进行了赖草和沙生苔草克隆生长特性研究。结果表明:赖草克隆构型指数为0.91,对应一维自回避行走模型,而沙生苔草克隆构型指数为0.78,对应随机行走模型;赖草克隆生长指数为0.88,沙生苔草克隆生长指数为0.21;赖草适于利用广域分布资源,沙生苔草适于极度利用局部资源;赖草和沙生苔草有不同的风险分摊方式,即赖草将风险分摊在一条或几条线上,而沙生苔草将风险分摊在一个面内。
     为进一步揭示赖草和沙生苔草在拓展新生境时对克隆整合效应的依赖性质和依赖程度,进行了以切断根茎为处理的试验,结果表明:在测定的各项植物特征中,伸长生长对克隆整合有极高的依赖性,而数量性状基本不受整合效应影响;生殖生长与营养生长的调控受整合效应的制约;赖草用于移植时要求具有较多的地上枝,而沙生苔草要求具有较高的种植密度。
     在进行了人工建植群落入侵种分析之后,进行了非生物关键生态因子影响
Aiming at the current steppe in the northwest of Sichuan facing the serious degeneration even the threat of desertification, the revegetation experiments were conducted on the northwest plateau sandback of Sichuan, and various reconstruction modes were established. The analysis to the reconstructive community indicates that the diversity of species in the community reduces with the increase of the eveness, and they are negative related (coefficient of correlation 0.94, linear regression Y = -0.14x + 0.75). Species diversity enlarges with the increase of the abundance, they are positive related (coefficient of correlation 0.85, linear regression Y = 0.17x -0.15). In all reconstruction modes, community T10 (Elymus sibiricus+ Bromus inermis+ Lolium multiflorum) has the best stability, and community T13 (Elymus nutans+ Lolium multiflorum+ Festuca rubral Agropyron desertorum) has the strongest rivalrousness. Among all tested species, three have the biggest community dominance, which are Elymus sibiricus, Elymus nutans, and Agropyron desertorum.In the artificial reconstructive communities, two original vegetations, which are Leymus secalinus and Carex praeclara, have the strongest encroachment ability. For the further study on the revegetation mode combined with original vegetations, the research on clonal growth properties was conduced during Leymus secalinus and Carex praeclara. The results show that the clonal architecture index of Leymus secalinus is 0.91 in accord with the guerilla, and the growth form index of Carex praeclara is 0.78 in accord with the phalanx. The clonal growth index of Leymus secalinus is 0.88, and that of Carex praeclara is 0.21. Leymus secalinus is suited to make use of resources distributed extensively, while Carex praeclara is fit for using resources distributed narrowly. Leymus secalinus and Carex praeclara have different
    risk-spreading modes. The risk-spreading of Leymus secalinus is on one or several lines, while that of Carex praeclara is on a plane.In order to reveal the dependence property and degree of Leymus secalinus and Carex praeclara on clonal integation effect when develop new habitats, they are tested by cutting the rhizomes. The results suggest that among all tested plant properties the extention growth highly depend on clonal integation effect, but which hardly affects the quantity and the shape. The adjustment of the vegetative growth and reproductive growth are controlled by clonal integation effect, Leymus secalinus requires more shoots when explanted, while Carex praeclara needs higher planting density.After analyzing the intrusive species of the artificial reconstructive communities, the experiments concerning the influence of abiotic ecological factors were performed. In the three factors, moisture, temperature and light, which effect the vegetation distribution, the low temperature and the strong UV-B radiation are quite important on the northwest plateau of Sichuan, so corresponding experiments were taken. Elymus sibiricus is the representative species in the northwest of Sichuan, and Lolium multiflorum, as the comparison, has the power to resist low temperature. During the research on gene expression difference between them, it is indicated that ATPase gene is involved in the metabolizability under low temperature adversity. The full length gene of Elymus sibiricus is obtained by 5'- RACE, the analysis to its expression under low temperature shows that during the 4 to 8 hours after low temperature disposal or the 16 to 24 hours when free from being intimidated, the transfer of atpA gene evidently enhances. The correlative analysis also indicates that the a -subunit of ATPase not only has the power to adjust the enzymatic activity, but also relates to the plant signal transduction under low temperature. During the process of separating the differential expression genes under low temperature, the discoveries of some genes and fragments connected with mRNA posttranscriptional ragulation, DNA repair, signal transduction and adversity enzymes (eg. methionine synthase ) lay a foundation for the further studies on the low temperture resistance of plateau plant.On the Tibetan plateau, the ozone hole is enlarging, and the UV-B radiation is strengthening. In this condition, the gene expression difference of Elymus sibiricus
    radiated by enhanced UV-B was analyzed, and some gene fragments homologous with phosphatidylserine decarboxylase gene and retrotransposons gene were seperated. It suggests that these fragments are involved in UV-B signal transduction and gene mutation. The rbcL gene controled by UV-B was seperated at the same time. The analysis on the full length gene of rbcL cloned by 5' RACE and its expression under enhanced UV-B shows that: Northern hybridization analysis on the rbcL expression during the time of enhanced UV-B radiation, showed that the mRNA level of the rbcL descended obviously after 6h enhancing UV-B radiation, and 60h later, the mRNA even couldn't be detected. The. E. sibiricus cv. 'chuancao No.2' growing in the plateau area for a long time, radiated strongly by the UV-B, the rbcL transcription of Elymus sibiricus L might be restrained like the plain plants which are sensitive to UV-B. This result provides a new clue for revealing the role of some factors such as PAR, temperature and the concentration of CO2 in the alpine plants adapting to strong UV-B radiation.
引文
1 杨玉坡,李承彪.四川森林.北京:中国林业出版社,1992
    2 赵士洞,汪业勖.生态系统管理的基本问题.生态学杂志,1997,16(4):35~38
    3 郑度,张荣祖,杨勤业.试论青藏高原的自然地带.地理学报,1979,34(1):1~9
    4 吴宁,刘照光.青藏高原东部亚高山森林草甸植被地理格局的成因探讨.应用与环境生物学报,1998,4(3):290~297
    5 赵仁昌.若尔盖草地沙化及防治对策.四川环境,1995,14(2):15~20
    6 黎怀鸿,王玉蛟.川西北牧区草地生态环境综合整治的思考.四川草原,1999,4:5~8
    7 王庆琐,王襄平,罗菊春等.生态交错带与生物多样性.生物多样性,1997,5(2):126~131
    8 刘庆.青藏高原东部(川西)生态脆弱带恢复与重建研究进展.资源科学,1999,21(5):81~86
    9 邓培华.阿坝牧区草地畜牧业与草地生态建设初探.草业科学,2003,20(1):36~38
    10 刘世建.青藏高原东北部若尔盖盆地荒漠化.山地研究,1997,15(2)119~123
    11 任继周主编.1998.草业科学研究方法.北京:中国农业出版社,130
    12 孙儒泳,李博.1993.普通生态学.北京:高等教育出版社,136
    13 张大勇,王刚,杜国祯等.亚高山草甸弃耕地植物群落演替的数量研究Ⅰ.群落组成分析.植物生态学与地植物学学报,1998,12(4):283~291.
    14 董世魁,胡自治,龙瑞军.高寒地区多年生禾草混播草地的群落学特征研究.生态学杂志,2003,22(5):20~25
    15 石永红,符义坤,李杨春等.半荒漠地区绿洲混播牧草群落稳定性与调控研究.草业科学,2000,9(3):1~7
    16 宝音陶格涛,刘美玲,李晓兰.退化羊草草原在浅耕翻处理后植物样落演替动态研究.植物生态学报,2003,27(2):270~277
    17 杨锦忠.不同生长阶段群体数量特征队产草量作用的分析[j].草地学报.1997,5(1):48~53
    18 曲仲湘.1983.植物生态学.北京:高等教育出版社.134
    19 West N E. Biodiversity of rangelands. Journal of Rangeland Management, 46: 2~13
    20 马克平,黄建辉,于顺利.北京东灵山地区值物群落多样性的研究Ⅱ.丰富度、均匀度和物种多样性指数.生态学报,1995,15(3):268~277.
    21 董世魁,胡自治.人工草地群落稳定性及其调控机制的研究现状.草原与草坪,2000,90(3):3~8
    22 张继义,赵哈林.植被(植物群落)稳定性研究评述.生态学杂志,2003,22(4):42~48
    23 Tihnan D. Biodiversity: population versus ecosystem stability. Ecology, 1996, 77(2)350~362
    24 Tilman D, Downing J A. Biodiversity and stability in grasslands. Nature, 1994, 367: 350~362
    25 杨万勤,钟章成,陶建平等.缙云山森林土壤酶活性与植物多样性的关系[J].林业科学,2001,37(4):124~128
    26 吴彦,刘庆,乔永康等.亚高山针叶林不同恢复阶段群落物种多样性变化及其对土壤理化性质的影响[J].植物生态学报,2001,25(6):648~655
    27 Doak D F, Bigger D, Harding E K, et al. The statistical inevitability of stability diversity relationships in community ecology. American Naturalist, 1998, 151: 264~276
    28 Tilman D. The ecological consequences of changes in biodiversity: a research for general principles. Ecology, 1999, 80: 1455~1474
    29 Tilman D. Causes, consequences and ethics of biodiversity. Nature, 405: 208~211
    30 Tilman D, Lehman C L, Bristow C E. Diversity stability relationships: statistical inevitability or ecological consequence? American Naturalist, 1997, 371: 114~114
    31 Ives A R, Gross K, Klug J L. Stability and variability in competitive communities. Science, 1999, 286: 542~544
    32 Tilman D. Biodiversity: population versus ecosystem stability. Ecology, 1996, 77: 350~363
    33 白永飞.陈佐忠.西林河流域羊草草原植物种群和功能群的长期变异性及其对群落稳定性的影响.植物生态学报,2000,24(6):641~647
    34 James B, Mcgraw F, Stuaru C. Competitive ability and adaptation to fertile and infertile soils in two Eriophoywn species[J]. Ecology, 1989, 70(3): 736~749
    35 王刚,张大永.生物竞争理论[M].西安:陕西科学技术出版社,1996
    36 Aarssen L W, Turkington R. Competitive relations among species from pastures of different ages[J]. Canadian Journal of Botany, 1985, 63: 2319~2325
    37 李向林.1996.杂草—作物干扰机制及杂草生态防治研究.兰州:兰州大学生命科学学院
    38 李博.普通生态学[M].呼和浩特:内蒙古大学出版社,1993
    39 董世魁,龙瑞军,胡自治等.高寒地区多年生禾草人工草地杂草种群动态研究.兰州大学学报,2003,39(5):82~87
    40 Deboran E. Neighborhood competition in an old field plant community[J]. Ecology, 1987, 68(5): 1211~1223
    41 Bazzaz F A. Plant interaction in successional environment [A]. In: Grance J B, Tileman D. Perspective on plant competition[M]. San Diego, California, USA: Academic press, 1990
    42 Mxlendon T, Tedente E F. Nitrogen and phosphorus effects on secondary succession dynamics on a se mi arid sagebrush site[J]. Ecology, 1991, 72(6): 2016~2024
    43 王刚,吴明强,蒋文兰.人工草地杂草生态学研究[J].草业学报,1995,4(3):75~80
    44 孙海群.混播人工草地退化演替的研究.中国草地,2000,2:8~14
    45 苏德毕力格,周禾,王培.退化混播人工草地白三叶繁殖特性的变化[J].草地学报,1998,6(1):68~71

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