土壤有效磷含量对棉花幼苗干物质积累和碳氮代谢的影响  

Effects of Soil Olsen-P Levels on the Dry Matter Accumulation and Carbon and Nitrogen Metabolism of Cotton Plant at Seedling Stage

作　　者：王刚[1] 郑苍松[1] 李鹏程[1] 刘敬然[1] 刘爱忠[1] 孙淼[1] 赵新华[1] 余学科[1] 董合林[1] 

机构地区：[1]中国农业科学院棉花研究所/棉花生物学国家重点实验室,河南安阳455000

出　　处：《棉花学报》2016年第6期609-618,共10页Cotton Science

基　　金：国家现代农业产业技术体系--棉花体系(CARS-18-17);国家科技支撑计划(2014BAD03B02);农业部行业专项(201503121;201203096)

摘　　要：苗期为棉花对磷吸收最敏感时期,然而现有研究未能明确土壤有效磷含量对苗期棉花干物质积累和碳氮代谢的影响以及适宜的土壤有效磷含量。本研究以"中棉所79"为供试品种,采用盆栽试验,研究了不同土壤有效磷水平下,五叶期棉苗干物质质量、碳氮代谢、功能叶片叶绿素含量及磷的吸收和利用。结果表明,随着土壤有效磷含量的增加,棉苗干物质质量逐渐增加,根冠比逐渐降低;土壤有效磷含量在9.0 mg·kg^(-1)时,棉苗干物质质量达到最大值,根冠比最小;过高的磷素营养对干物质质量的积累没有显著促进作用。叶片叶绿素含量随着土壤有效磷含量的增加呈现出先增加后减少的趋势,在土壤有效磷含量为7.2 mg·kg^(-1)时达到最大值。各处理棉苗中的蔗糖、可溶性糖、淀粉和氨基酸总量先随着土壤有效磷含量的增加呈显著增加趋势,在9.0mg·kg^(-1)时达到最大值,随后开始下降但差异不显著。土壤有效磷含量的增加可以促进棉苗的磷吸收量和磷根效率比,抑制磷利用效率,但对磷转移效率没有显著影响。因此,低磷会降低棉花幼苗叶绿素含量、糖含量和氨基酸总量,导致棉花生长受到抑制,适宜棉花幼苗生长发育的土壤有效磷的临界含量为9.0 mg·kg^(-1)。The seedling stage is a sensitive period when cotton plants absorb phosphorus （P） from the soil. However, the suitable Olsen-P level during this period, and the effects of soil Olsen-P levels on the dry matter accumulation, and the carbon and nitro- gen metabolism of cotton plants, were not clear. Thus, we conducted a pot experiment to explore the effects of soil Olsen-P lev- els on the growth of cotton （CCRI 79） plants and their physiological mechanisms in 2014 and 2015. The dry matter of the cotton seedling increased as the available soil P concentration increased in the treatments, but the root to shoot ratio decreased. There was no significant effect on the cotton plant＇s growth in soils with higher Olsen-P levels. However, the dry matter accumulation was highest in the 9.0 mg.kg-~ Olsen-P treatment, but it had the lowest root to shoot ratio of 0.3. The total chlorophyll content of the functional leaves significantly increased and then decreased as the available soil P concentration increased in the treatments. It was highest in the 7.2 nag·kg^-1 Olsen-P treatment, which influenced the concentrations of chlorophyll a more strongly than chlorophyll b. The sucrose, soluble sugar, starch and total amino acid contents significantly increased as the available P concen- tration increased, but did not steadily increase at concentrations greater than 9.0 mg. kg^-1. As the available soil P concentration increased, the P absorption significantly improved, but the root P efficiency ratio significantly decreased in the cotton seedlings. Thus, the lower soil Olsen-P level affected cotton leaf chlorophyll and sugar contents, as well as the total amount of amino acids to restrain cotton growth, and the critical Olsen-P level was 9 mg·kg^-1 for cotton plant growth at the seedling stage in our experi- ment.

关 键 词：棉花 有效磷 根冠比 碳水化合物 吸收利用效率 

分 类 号：S562[农业科学—作物学]