【作者】 梁霞；

【导师】 马祥庆；

【作者基本信息】 福建农林大学 ， 森林培育， 2004， 硕士

【摘要】 磷素不足是限制目前世界农林业生产的重要因素，传统的农林业生产主要通过施肥和土壤改良来满足植物对磷的需求，很少从提高植物对土壤的磷素利用效率考虑，因此发掘磷高效利用植物来替代传统方法提高磷的利用效率成为当前林业生产中急需解决的重大课题。 针对目前杉木连栽生产力下降防治研究主要是从改良土壤条件来适应杉木生长、而不是通过选择养分高效利用杉木来适应土壤条件的现实，本研究在对从全国收集到125个杉木无性系及其子代林速生性、耐肥性调查基础上，初选14个不同的杉木无性系，通过土培和水培的磷素胁迫试验，分析测定磷胁迫条件下不同杉木无性系的形态学和生理学指标，比较各指标间的相关性和不同杉木无性系对养分胁迫的生理生态学反应差异，研究不同杉木无性系对磷素胁迫的形态学和生理学响应，寻求杉木无性系通过形态学及生理生化过程适应性改变来调节自身养分吸收的机制，并选择磷高效特异性指标，为高磷素利用效率的杉木无性系的筛选提供科学依据。主要研究结果如下： 1、对磷素胁迫条件下不同杉木无性系地径、苗高和根冠比等形态学指标的研究结果表明：在磷素胁迫条件下不同杉木无性系的地径和苗高明显下降，但杉木地下部分根冠比变化规律不明显。在磷素胁迫条件下不同杉木无性系形态学指标存在明显差异，其中37、8、24号无性系的形态学指标对磷胁迫不敏感性，在胁迫条件下仍能保持一定的高生长，能够适应缺磷环境下的生长：而3、5、23、34号无性系的形态学指标对磷胁迫比较敏感，在磷素充足时生长良好，但在胁迫条件下生长明显受阻：9号无性系的形态学指标对磷胁迫的敏感性则介于以上两类无性系之间。 2、对磷素胁迫条件下不同杉木无性系的生理生态学指标的研究结果表明：磷胁迫条件下不同杉木无性系的酸性磷酸酶活性、根系质子分泌量、根系磷离子动力学参数、光合特性等生理生态指标发生了一定变化。磷胁迫引起了杉木无性系根系质子分泌量增加、根际PH值的下降、叶片和根系的酸性磷酸酶活性增强、根系吸收动力学参数中的I_max增加、K_m和C_min下降、叶片叶绿索含量下降、光合速率降低、呼吸速率增加、CO₂补偿点增高。 否网誉本无丝圣塑塑些鲤垫鲤哩鱼_<sub>3、对磷素胁迫条件下不同杉木无性系的形态和生理生态学指标的相关性研究结果表明: 磷素胁迫条件下不同杉木无性系形态和生理生.态指标之间存在一定的相关关系，但除 了根冠比与根际PH下降值之间呈负相关性，苗高与叶绿素之间有显著正相关关系外， 其它均不明显。生理生态指标中的根际PH下降值与叶片和根际酸性磷酸酶活性呈极 显著正相关，且相关系数较大，叶片与根际酸性磷酸酶活性之间也存在显著的正相关 性。说明胁迫条件下，杉木无性系会通过根系酸性物质的分泌和植株酸性磷酸酶活性 的提高而增强对环境磷素的吸收和再利用能力。4、土培磷胁迫的研究结果表明:在磷胁迫条件下不同杉木无性系的生理生态指标变化存 在明显差异。8、9、24、37号杉木无性系在磷胁迫条件下表现出较强的根际酸化能 力，随磷胁迫加剧，其叶片与根系的酸性磷酸酶活性显著增强，叶绿素含量下降程度 变小，这4种无性系对环境缺磷胁迫的适应能力较强，在中低磷的林地上可通过生理 生态过程的适应性改变来维持杉木对磷的利用;23号和34号无性系在磷胁迫条件下 根际的PH和APA活性对磷胁迫不敏感，变化较小，随磷胁迫的加剧，其叶绿素含 量下降明显，这2种无性系对环境缺磷胁迫的适应性较差;而3号、5号无性系生理 生态指标对磷胁迫的敏感性介于以上两类无性系之间。5、对土培条件下杉木无性系干物质积累量、磷索吸收和利用效率之间的相关关系以及影 响这三项指标的形态、生理学指标进行筛选。研究表明，磷素吸收效率在各处理水平 与千物质积累量始终呈极显著正相关，植株磷素利用效率在胁迫条件下与根际PH一卜 降值呈极显著正相关，_巨相关系数较大。因此，干物质积累量能够表明植株磷吸收能 力的大小，而根际PH下降值则可表征植株磷素利用能力，这两项指标可作为严格而 可靠的综合评价筛选生理指标。除此之外的其它指标与植株干物质积累量、磷素吸收 效率和利用效率在某一胁迫阶段呈极显著或显著相关，可作为该胁迫条件下的间接筛 选指标，但不能作为综合评价筛选因素。6、营养液培养磷胁迫的研究结果表明:在磷胁迫条件下不同杉木无性系的生理生态指标 变化存在明显差异。随磷胁迫程度和胁迫时间的增加，2、8、12、24号无性系的根 际质子分泌量‘△PH=PH。一PH)迅速增加，酸性磷酸酶活性增强，叶绿素含量下降 程度变小，这四种无性系对磷胁迫的反应灵敏。而在磷胁迫条件下11、21号无性系 的根际分泌质子量较低，随胁迫时间的延长.和胁迫程度的加重，其酸性磷酸酶活性表福建农林大学2004届硕士研究生论文 现出缓慢增长趋势，叶绿素含量则迅速降低，根系吸磷能力变弱，这两种无性系对环 境磷胁迫的适应能力较差。13和44号无系性对磷胁迫的反应能力介于以上两类无性更多还原

【Abstract】 At present, phosphorus has played an important role in agricultural and forestry production limits in all worlds. The traditional agricultural and forestry productions have met plants’ phosphorus demands mainly by fertilizing and soil improvement, and have paid less considering in the improvement of plants phosphorus-utilize efficiency. So discover high phosphorus-utilize efficiency plants to substitute the traditional ways to improve the phosphorus-utilize efficiency has become an important task to be settled in currently forestry production.For the present status of buffering the soil declining caused by successive planting mainly by the improvement of soil condition to adapting Chinese fir growth, but not by selecting high fertilizer- utilize efficiency Chinese fir to adapting soil condition, this research primary collecting 14different nutritional efficiency genotypes, base on the investigating of fast-growing, fertilizer response of 125 Chinese firs clones and their filial clones, which are collected from whole country. The index of morphological and physiological was studied by pot test and solution culture under low phosphorus stress and compare the physiological response difference of different Chinese fir clones for fertilizer stress. Study the morphological and physiological response of different Chinese fir clones under phosphorus stress, seek the morphological and physiological adaptation mechanisms by which plant regulate the fertilizer absorbing and provide science foundation to the selecting of high phosphorus-utilize efficiency Chinese fir clones. The main results as follows:1. The morphological index of DBH , seeding height and dry matter distributing of different Chinese fir clones were studied under phosphorus deficiency stress. The results showed that the aggravation of phosphorus deficiency would lead to the decline of the DBH, seeding height, and the allocation of dry matter to roots have non-obviously increase. The morphological index showed distinct differences between different Chinese fir clones under phosphorus stress. Itwas found that 37, 8, 24 with the highest productivity under low phosphorus was excellent clones with the least sensitivity to phosphorus supply, which may be adapted in low phosphorus environments, while clones 3 , 5, 23 , 34 were sensed to phosphorus stress, which may grow well under the phosphorus abundant environment and the growth would be obviously affected under stress condition. The morphologic index of No.9 clones showed a medium character between the two types clones.2. Compare the physiology-ecological responses of different Chinese fir clones, the results showed that the intensity of activities of acid phosphatase, rhizosphere acidification, P kinetic parameters and the photosynthesis-respiration rate are all changed by phosphorus stress. In stress environment, the intensity of rhizosphere acidification was stronger and PH in rhizosphere was decreased obviously, the activities of acid phosphatase were higher than those under normal P treatment. With the amelioration of phosphorus, the Imax, decreased while Km and Cmm increased in all clones, the chlorophyll contents and photosynthesis rate decreased considerably, and the respiration rate and CO2 compensation points were enhanced responsibly.3. The correlation of morphology and physiological ecology indexes of different Chinese fir clones under phosphorus stress were studied. The results showed that the morphology and physiology7 ecological indexes of different Chinese fir clones have certain correlations. Besides the negative correlations of root-hat radio and decline data in rhizosphere PH, the remarkable positive correlation of seedling high and chlorophyll, other indexes didn’t show obvious correlations. The physiological ecology indexes of decline data in rhizosphere PH and the activities of acid phosphatase in leaves and in rhizosphere submitted remarkable positive correlation, and the correlation coefficient were higher; there were also remarkable positive correlation in the activities更多还原