不同硼效率棉花品种根系参数和伤流液组分的差异

溶液培养条件下研究硼对不同硼效率棉花品种根系参数、伤流量及伤流液组分的影响。结果表明,缺硼抑制棉花根系生长,根重、根体积、根长、活跃吸收面积、总吸收面积、活跃吸收面积占总吸收面积的比例以及伤流量均显著降低,高效品种降低幅度比低效品种小;缺硼还使高效品种根系比表面积升高,而低效品种无显著变化。缺硼显著影响不同棉花品种伤流液各组分含量,与低效品种相比,高效品种伤流液中有较多的NO3-、K+、无机磷、可溶性糖和游离氨基酸。说明缺硼条件下高效品种根系比低效品种具有更强的吸收、代谢活力,可能是其硼效率较高的主要原因之一。

Differences in Root Characters and Composition of Root Bleeding Sap between Several Cotton Cultivars with Different Boron Efficiency

The differences of the root characters and the composition of root bleeding sap between two B-efficient cotton cultivars and two B-inefficient ones were studied under solution cultivation.The root growth and development of all cotton cultivars was inhibited by B deficiency,for examples,the weight, volume,active and total absorption area of their roots were decreased significantly,and those of B-inefficient cultivars declined more seriously than the B-efficient ones.The ratio of root absorption area to root volume of the B-efficient cultivars was increased by boron deficiency,while that of the B-inefficient ones was not markedly changed.The amount of bleeding sap in the cotton cultivars was seriously depressed by B deficiency,but with higher intensity in B-inefficient ones.The total amount of NO~-_3,K~ ,inorganic phosphorus,soluble sugar and free amino acid in the bleeding sap of B-efficient cultivar was more than of B-inefficient one under the stress of B deficiency.The results suggested the capability of absorption and metabolism in the roots of B-efficient cotton cultivar was greater than that of B-inefficient one in low B supply,which might be an important reason that B efficiency was different between cotton cultivars.