【作者】 刘奕琳；

【导师】 万福绪；

【作者基本信息】 南京林业大学 ， 水土保持与荒漠化防治， 2013， 博士

【摘要】 本文以10种不同种源墨西哥柏D1(La presa)、D2(Pinal de amoles)、D3(La cienega)，D4(Lacumbre del manzano)、D5(Dos aguas)、D6(Camino a la mesa)、D7(Ejido pio frio)、D8(Comunalsan francisco)、D9(Tequesquinahuac)、D10(Ejido sierra de agua)为研究对象，采用野外观测与室内实验相结合的方法，系统研究了墨西哥柏幼苗生长规律及光合作用特性、各种施肥措施对墨西哥柏幼苗生长特性的影响、旱盐逆境胁迫对墨西哥柏的生理生化影响，获得的主要成果如下：各种源地墨西哥柏幼苗均符合“S”型生长曲线的累计生长规律，回归效果显著，R2达到0.98以上。不同种源间地上地下特征差异显著。D2拥有较为发达的根系组织；D5地上部分高生长生长较为明显；D1各生长指标都较为均衡。在种子萌发期，低盐浓度胁迫下，D1、D10种源的墨西哥柏种子的发芽率有所略微提高，其余种源都下降，下降幅度较小，但发芽势、发芽指数和种子活力指数均随NaCl浓度的增加而明显下降。一年生苗木，盐分胁迫对各种源墨西哥柏苗木形态及生长均产生显著影响，苗高生长和地径生长均受到明显的抑制，对苗高生长的影响大于对地径生长的影响，且各种源间苗高影响差异显著。轻度干旱对苗木生长有促进作用，重度干旱抑制苗木生长。干旱胁迫抑制了墨西哥柏苗高的生长，D4种源受抑制程度最大。重度干旱下对根系生长抑制作用显著，与对照相比根系总长度均大幅度下降，轻度干旱促进了根系的均匀生长；重度干旱只能促进0.0～1.0mm等级的根系生长。干旱胁迫促进了墨西哥柏幼苗地径的生长，除D6、D7、D9和D10种源，其他均出现明显的促进作用。在胁迫初期干旱对细胞膜系统造成了伤害，而后期则可能因为适应干旱环境从而恢复了膜系统，导致电导率含量下降。随着胁迫时间的延长和胁迫梯度的增大，墨西哥柏的叶绿素a（Chla）、叶绿素b（Chlb）和叶绿素总量（Chla＋Chlb）都有不同程度的下降，在一定程度上降低了叶片的光合作用能力。干旱胁迫导致墨西哥柏针叶丙二醛（MDA）含量有不同程度的增加，最大为D3种源，在干旱T4处理下MDA含量高达290.41nmol/g。D5-D10六个种源仅在干旱胁迫在土壤含水量低于田间最大持水量的10%以下时伤害最大。墨西哥柏过氧化物酶（POD）活性在持续干旱胁迫下随着胁迫梯度的增大和胁迫时间的延长变化趋势不明显，在干旱胁迫下墨西哥柏能够通过POD活性的提高而在一定程度上保护细胞膜，使自由基维持在一个较低水平上，从而防止自由基对细胞膜更严重的伤害。在胁迫末期还出现了POD活性下降的现象，暗示了墨西哥柏抗氧化能力的衰退。干旱胁迫下，随干旱时间和干旱程度的增加，墨西哥柏脯氨酸含量均有不同程度的积累。可溶性蛋白质含量变化与可溶性糖浓度变化相似。10种墨西哥柏在干旱强度T1和T2处理下随时间的延长，可溶性糖浓度呈先上升而后下降的趋势。D6、D8、D9和D10种源只在干旱强度T4处理下可溶性糖浓度呈一直上升的趋势，说明在这种干旱强度下这四种植株受到了伤害，其它处理下可溶性糖浓度的变化趋势与对照相似，无显著差异，抗旱性较好；D1和D7种源在处理T3和T4两个梯度下可溶性糖浓度呈一直上升的趋势，抗旱性较差。采用主成分分析法、隶属函数法、权重法等多种方法对实验中分析的16个指标（苗高、地径等）进行综合评价，10种墨西哥柏种源的抗旱性由强到弱的顺序为：D9、D5、D3、D10、D8、D7、D6、D1、D4、D2。把苗高、地径、叶片含水量、叶绿素总含量、相对电导率含量、脯氨酸和丙二醛含量7个参数因子值代入模型，根据隶属函数法综合评价各种源耐盐能力，筛选出了强耐盐抗旱种源为：D10（Ejido sierra de agua）、D3（La cienega）。更多还原

【Abstract】 Cupressus lusitanica, a provenance from Mexico, is an evergreen arbor tree with highdrought tolerance and saline tolerance. With10provenances of Cupressus lusitanica fromMexico, D1(La presa), D2(Pinal de amoles),D3(La cienega)，D4(La cumbre del manzano)、D5(Dos aguas), D6(Camino a la mesa), D7(Ejido pio frio), D8(Comunal san francisco)、D9(Tequesquinahuac), D10(Ejido sierra de agua), their growth law, photosynthesischaracteristics and physiological characteristics under drought and saline diversity stress wasstudied and results are as follows:Cupressus lusitanica grew well in Nanjing and their growth of seedlings showed logisticcurve with growing days, whose R2was all more than0.98. There was great difference for theroot system and above ground growth among different types of provenance. For the D2provenance, it was with developed root system while the D5provenance was the highest. The D1provenance grew averagely for root, height and stem.Under low stress of saline, germination rate of D1, D10types improved a little while that forthe other tree types decreased a little. Germination energy, germination index, and seed viabilitydecreased with NaCl concentration. For one year seeding of Cupresses lusitanica, saline stressaffected their shape and growth of all types of provenance outstandingly. Height growth andground diameter growth was urged and its effect on height was higher than that of grounddiameter. There existed outstanding difference among10types of provenance.Light drought improved the growth of seeding and heavy drought urged the growth ofseeding of Cupressus lusitanica and the extent differed quietly according to its provenance.Drought urged the growth of Cupressus lusitanica, especially the D4provenance suffered themost seriously. Under heavy drought, there root growth decreased sharply except the root withdiameter between0.1-1.0mm grew well compared with the contrast. Light drought improved theaverage growth of root system. Drought also improved the growth of ground diameter ofCupressus lusitanica seedlings form the province of D1, D2, D3, D4, D5and D8.Their physiology and biochemistry reaction to light drought showed uniform while variedgreatly to heavy drought. At the early stage of drought stress, conductivity increased due to thedamage to the cell membrane by water loss. While in the lateral stage of drought, conductivitydecreased, which may be inferred due to the adaptability of seedlings to drought stress. With theextending of time and increase for drought stress, content of a（Chla）,b（Chlb）and （Chla＋Chlb）decreased and the ability for photosynthesis of leaves decreased correspondingly.Under drought stress,（MDA）in the needle leave of seeding of Cupressus Lusitania increased,among which, it was the highest for the D3provenance under T4drought level, whose MDAcontent in the leave was as high as290.41nmol/g. For the D5-D10provenances, drought stressmade the great damage when the soil water content was less than10%of the max field capacity of soil water. The activity of（POD）did not show outstanding change with the increase of droughtstress and time, showing strong function of protecting cell membrane. At the end of drought stress,it decreased suddenly, showing decline of antioxidant capacity. Proline content increased with thedrought stress at different levels for the ten provenances.For the10provenances, under drought stress of T1and T2level, soluble sugar content in theleaves increased at first and then decreased to its original level. For the D6,D8,D9and D10provenances, their soluble sugar content increased from1.0μ mol/g to3.5μ mol/g under T3and T4levels of drought stress, showing strong damage to seedlings. For the other provenances, therechange of soluble sugar content in the leaves varied similiarly with the contrast, showing lowdamage. For theD1and D7provenances, their soluble sugar content increased from1.0μ mol/g to4.5μ mol/g under T3and T4levels of drought stress, showing high damage.With principal component analysis, membership functions, weighting method, syntheticevaluation model of seeding saline and drought resistant ability was constituted. Instituting thevalues of height, ground diameter, volumetric water content, total content of chlorophyll, relativepermeability of cell membrane, mda and proline under saline stress and drought stress respectivelyinto the models, the order for drought resistance was D9、D5、D3、D10、D8、D7、D6、D1、D4、D2, while the order for saline resistance was D10（Ejido sierra de agua）and D3（La cienega）.更多还原