【作者】 黄国伟；

【导师】 黄秦军；

【作者基本信息】 中国林业科学研究院 ， 林木遗传育种， 2012， 硕士

【摘要】 为探求杨树（Populus）杂交子代不同生长势群体的生长生理特征差异及生长优势发生的生理基础，以高（A）、低（B）生长势两个群体及母本南杨（P.deltoides cl.‘Nan’）幼苗为实验材料，开展不同时期生长性状、光合生理特征及养分吸收等相关研究。结果表明：1、高、低生长势无性系在根、茎、叶的干重及总干重上差异显著或极显著，总干重最大值A3为33.25g，而最小值B2仅12.82g。所有无性系不同器官干物质分配上根干重比例最小，叶和茎所占比例大。高生长势群体干物质分配茎所占比例平均为45.15%，而低生长势群体茎所占比例平均为39.82%，优势群体干物质分配倾向于茎，而低生长势群体则倾向于叶。2、从6月到9月，幼苗生长和生理特征变化呈现一定的规律性，不同生长势间特征值存在显著的差异性。不同月份间7月份各系号生长最快，生理特征值变化幅度最大；相关性分析表明，苗高和地径的大小与单叶面积、夜间呼吸速率、NH4+的吸收速率及总光合速率均呈显著相关（R>0.826，P<0.05），表明幼苗生长主要受自身总光合能力、养分吸收和夜间呼吸消耗的影响。3、不同生长势及亲本无性系Pn日变化曲线均为双峰型，第1峰值均出现在10:00左右，但F的第2峰值出现在14:00，而A4和B3的第2峰值出现在16:00；光响应曲线数据分析表明，不同生长势间除Rd外，Pnmax、AQY、LCP、LSP等差异均达到显著，高生长势无性系中Pnmax最大可达21.47μmol.m-2.s-1，超过低生长势39.42%，高生长势无性系的LCP较小，同时LSP值又较大，分别超过低生长势无性系及亲本17.03%和10.35%。4、CO2响应曲线数据分析表明，各系号间仅Pnmax差异显著，羧化效率、CCP、光呼吸速率等差异均不显著，高生长势无性系的羧化效率略高于低生长势无性系及亲本，而CCP则稍低于低生长势无性系及亲本，表明高生长势植株在CO₂的转化效率和利用效率上稍有优势。总之，高生长势无性系利用弱光的能力较强，且能在强光下进行相对高效的光合作用，但对于CO2的吸收利用能力仅略有优势。更多还原

【Abstract】 To investigate differences in physiological characteristics of growth and physiologicalbasis of high growth vigor in the first generation of Populus deltoides which are from differentgrowth vigor clones,here we chose two groups of seedlings with different growth vigor:HIGH(A) and LOW (B), for comparison,with the Parents as controls. Indexes of phenotypeand physiology were successively measured to study the growth,photosynthesis and nutrientabsorption,and related research was carried out in the field of growth, photosynthesis andnutrient absorption. The research results in:1、There were significant or very significant differences in dry weight of root, stem,leafand the total between A and B.A3was the maximum value of total dry weight,reached33.25g,and the minimum was B2,only12.82g. The dry matter of root was assigned the minimum indifferent components. The largest proportion was stem in A,the mean was45.15%, while it wasthe leaf in B, and the mean of stem was39.82%in B.2、Changes in growth and physiological characteristics showed a certain regularity duringJune to September.All clones grew most rapidly and physiological characteristics varied mostsignificantly in July;Correlation analysis showed that seedling height and ground diameterwere both significant correlated to leaf area, night respiration rate, NH4+uptake rate and thetotal photosynthetic rate(R>0.826，P<0.05), suggesting that seedling growth was mainlyaffected by their own total photosynthetic capacity, nutrient absorption and night respirationconsumption.3、Diurnal changes of the net photosynthetic rate both showed two-peak curve in the allclones, the first peak all occurred at around10:00, while A carry out efficient photosynthesissignificantly earlier than B and Parents; Analysis of the light response curse showd that Pnmax,AQY, the LCP and the LSP achieved significant differences in addition to Rd. The largest Pnmaxreached21.47μmol. m-2.s-1in A,52.8%higher than B.The LCP of A was the smallest, Only 15.09μmol. m-2.s-1, however, its LSP was Maximum,17.03%and10.35%higher than B andParents respectively.4、Analysis of the CO2response curse showd that there were no significant differences incarboxylation efficiency, CCP and photorespiration rate except Pnmax. The carboxylationefficiency of A was a little higher than B and Parents, but the CCP was a little lower, revealedthat high Growth Vigor clons had a slight advantage in the utilize of CO2. Overall, high GrowthVigor clons had a strong ability to use in low light and carry out relatively efficientphotosynthesis in strong light, But only a slight advantage on the absorption and use of CO2.更多还原