不同磷水平对柱花草形态学指标的影响

Effects of different phosphorus concentrations on morphological indexes of Stylosanthes guianensis

关键词:  柱花草, 供磷水平, 形态特征, 磷效率, 生物量

Key words:  Stylosanthes guianensis, phosphorus supply, morphological characteristics, phosphorus-efficiency, biomass

摘要:

在不同磷素水平培养条件下,探讨磷胁迫对柱花草形态指标及生物量的影响,评价柱花草对磷浓度的耐受性。该文以12个不同基因型柱花草品种为材料,设置7个磷肥梯度, 分别为0.2、0.1、0.075、0.050、0.035、0.02 g·kg^-1,以不施磷肥为对照,采用盆栽方法进行施肥试验,比较不同柱花草品种形态指标对不同磷浓度的响应及生物量状况,旨在筛选出磷高效的柱花草品种。结果表明:(1)随着土壤磷浓度的逐渐增大,各品种柱花草均呈现分枝数、株高和茎粗均逐渐增大,根长逐渐减小,地上部分和地下部分生物量升高的趋势。(2)在低磷和高磷处理下‘西卡'、‘库克'柱花草的地上生物量均小于每株9.64 g(以供试材料中最高生物量的约2/3为临界线),为磷低效型柱花草; ‘有钩'、‘GC1463'柱花草的地上生物量均高于每株9.64 g,为磷高效型柱花草; ‘澳克雷'、‘CIAT11365'、‘格拉姆'、‘爱德华'(90080-2)、‘热研5号'、‘Capitata'、‘GC1480'、‘GC1576'柱花草的地上生物量在低磷处理下小于每株9.64 g,在高磷处理下高于每株9.64 g,为磷敏感型柱花草。土壤磷含量对柱花草的形态指标影响较大,磷高效型柱花草对低磷土壤环境适应性较强。

Abstract:

Under the condition of different phosphorus levels, the effects of phosphorus stress on the morphological indexes and biomass of Stylosanthes guianensis were studied, and the tolerance of S. guianensis to phosphorus concentration was evaluated. Using 12 different genotypes of Stylosanthes species as the material, seven phosphate fertilizer gradients were set up, 0.2, 0.1, 0.075, 0.050, 0.035, 0.02 g·kg^-1, respectively, with no phosphate fertilizer as a control, and the fertilization experiment was carried out by potting method. The responses of different morphological indexes of different Stylosanthes species to different phosphorus concentrations and biomass status were compared. Designed to screen out phosphorus-efficient Stylosanthes species. The results were as follows:(1)With the increase of soil phosphorus concentration, the number of branches, plant height and stem diameter increased gradually, and root length decreased gradually, the biomasses of aboveground and underground parts increased.(2)Under the treatments of low phosphorus and high phosphorus, the aboveground biomasses of S. scabra ‘Seca', S. guianensis ‘COOK' were less than 9.64 g·plant^-1(taking about 2/3 of the highest biomass in the test materials as the critical line), which were phosphorus-inefficient Stylosanthes species; The aboveground biomasses of S. hamataev.verano, S. guianensis ‘GC1463' were higher than 9.64 g·plant^-1, which were phosphorus-efficient Stylosanthes species; The aboveground biomasses of S. guianensis ‘Oxley', S. guianensis TRPC90072, S. guianensis ‘Graham', S. guianensis ‘Endeavour', S. guianensis ‘Reyan No.5', S. capitata, S. guianensis ‘GC1480', S. guianensis ‘GC1576' were less than 9.64 g·plant^-1 under low phosphorus treatment, and the species were higher than 9.64 g·plant^-1 under high phosphorus treatment and were phosphorus-sensitive Stylosanthes species. The soil phosphorus content had a great influence on the morphological indexes of Stylosanthes species, and the phosphorus-efficient Stylosanthes species had strong adaptability to the low-phosphorus soil environment.