|
|||||
|
|
| 内蒙古典型草原优势种冷蒿和克氏针茅对土壤低磷环境适应策略的比较 | |
| 引用本文： | 刘娜娜,田秋英,张文浩. 内蒙古典型草原优势种冷蒿和克氏针茅对土壤低磷环境适应策略的比较[J]. 植物生态学报, 2014, 38(9): 905-915. DOI: 10.3724/SP.J.1258.2014.00085 |
| 作者姓名： | 刘娜娜 田秋英 张文浩 |
| 作者单位： | 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093 中国科学院大学, 北京 100049 |
| 基金项目： | 国家自然科学基金(31272234);国家自然科学基金(31470466);植被与环境变化国家重点实验室青年人才项目(2011qnrc08) |
| 摘 要： | 为探究典型草原植物长期共存的生理生态机制, 以典型草原的优势物种克氏针茅(Stipa krylovii)和冷蒿(Artemisia frigida)为材料, 采用基质培养方法, 通过比较不同供磷浓度对二者生物量、根系形态、质子分泌、酸性磷酸酶和有机酸分泌以及磷吸收利用效率的影响, 探讨克氏针茅和冷蒿对土壤磷缺乏的适应策略。研究结果表明: 冷蒿主要通过根系分泌酸性磷酸酶和酸化根际来适应低磷环境; 而克氏针茅主要是通过根系分泌有机酸(主要是苹果酸)来适应土壤磷缺乏。在低磷条件下, 克氏针茅和冷蒿的磷吸收效率没有显著差异, 但克氏针茅的磷利用效率显著高于冷蒿。随着供磷浓度增加, 二者的磷吸收速率增加, 磷利用效率降低。在生物量、地上部分性状以及根系生长方面, 克氏针茅和冷蒿对磷供给的响应都表现先增长后降低的趋势; 克氏针茅的生物量在外源供0.25 mmol·L-1磷时达到最大, 而冷蒿的生物量在外源供0.50 mmol·L-1磷时达到最大, 表明冷蒿对磷的生理需求高于克氏针茅。因此, 克氏针茅和冷蒿具备各自不同的适应土壤有效磷缺乏的生理策略, 这可能是它们在土壤贫瘠的温带典型草原长期共存的重要机制。 |
| 关 键 词： | 酸性磷酸酶 冷蒿 有机酸分泌 磷缺乏 根际酸化 根形态 克氏针茅 |
| 收稿时间： | 2014-04-04 |
Comparison of adaptive strategies to phosphorus-deficient soil between dominant species Artemisia frigida and Stipa krylovii in typical steppe of Nei Mongol |
|
| LIU Na-Na,TIAN Qiu-Ying,ZHANG Wen-Hao. Comparison of adaptive strategies to phosphorus-deficient soil between dominant species Artemisia frigida and Stipa krylovii in typical steppe of Nei Mongol[J]. Acta Phytoecologica Sinica, 2014, 38(9): 905-915. DOI: 10.3724/SP.J.1258.2014.00085 | |
| Authors: | LIU Na-Na TIAN Qiu-Ying ZHANG Wen-Hao |
| Affiliation: | State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China University of Chinese Academy of Sciences, Beijing 100049, China |
| Abstract: | Aims Artemisia frigida and Stipa krylovii are two dominant species in the typical steppe of northern China, and highly adapted to the local edaphic conditions. However, little is known about their ecophysiological traits in terms of adaptation to soil nutrient regimes in general and low available phosphorus (P) in particular. To understand the ecophysiological mechanisms by which the two species adapt to low P availability in soil, root morphological traits, acid phosphatase (APase) activity secreted by roots, exudation of organic acid, P uptake rate and P utilization efficiency in the two species were measured under varying concentrations of P supply in pot experiments. Methods Pot experiments were conducted to investigate the responses of the two species to varying concentrations of P supply by determining biomass, shoot and root morphology, average P uptake rate, P utilization efficiency, exudation of organic acid and acid phosphatase in A. frigida and S. krylovii. Important findings Phosphorus deficiency induced root-secreted APase activity and acidification of rhizosphere in A. frigida, while S. krylovii exhibited an enhanced exudation of malate from roots under phosphorus-deficient conditions. Stipa krylovii displayed similar P uptake rate to that of A. frigida, but its P utilization efficiency was markedly higher than in A. frigida under phosphorus-deficient conditions. The two species showed similar growth patterns in response to P deficiency, but A. frigida seedlings required higher external P level for their maximal growth than those of S. krylovii, suggesting that the two species have different physiological requirement for P. The different adaptive strategies between A. frigida and S. krylovii to the low soil P availability may provide an ecophysiological explanation for their co-existence in the infertile grassland in northern China. |
| Keywords: | acid phosphatase, Artemisia frigida')" >Artemisia frigida, exudation of organic acid, phosphorus deficiency')" >phosphorus deficiency, rhizosphere acidification')" >rhizosphere acidification, root architecture')" >root architecture, Stipa krylovii')" >Stipa krylovii |
| 点击此处可从《植物生态学报》浏览原始摘要信息 | |
| 点击此处可从《植物生态学报》下载免费的PDF全文 | |