论文部分内容阅读
在营养液培养条件下,以根据相对产量为指标筛选出的6个不同磷效率的小麦(Triticum aestivum L.)品种为材料,对其苗期在缺磷条件下生长、根冠磷含量及其分配,以及叶片韧皮部汁液中磷浓度等进行了比较研究。结果表明,缺磷抑制植株地上部生长,但刺激根系生长,导致植株根/冠比增加。无论在供磷或缺磷条件下,磷高效品种的根冠生长速率都低于磷低效品种。缺磷导致植株体内的磷含量下降,与根系相比,地上部磷含量的下降速率更快。但在缺磷条件下,不同磷效率的小麦品种根冠间的磷分配变化没有差异。研究发现,在正常供磷条件下,磷高效小麦品种的叶片韧皮部汁液中磷浓度较低,而磷低效品种的叶片韧皮部汁液中磷浓度较高。但开始缺磷后,磷高效品种的叶片韧皮部汁液中的磷浓度下降较慢,使其相对磷浓度较高。缺磷后10天,磷低效品种叶片韧皮部汁液中的磷浓度为供磷对照的35.9％,而磷高效品种叶片韧皮部汁液中的磷浓度为供磷对照的59％。
Under the conditions of nutrient solution culture, six wheat cultivars (Triticum aestivum L.) screened out according to their relative yield were used as materials. Under the phosphorus deficiency condition, Distribution, and leaf phloem juice phosphorus concentration were compared. The results showed that phosphorus deficiency inhibited shoot growth but stimulated root growth, resulting in an increase in plant root / shoot ratio. The root growth rate of high-P-efficient varieties was lower than that of low-phosphorus cultivars under phosphorus or phosphorus deficiency. Phosphorus deficiency led to the decrease of phosphorus content in plants, compared with the root system, the phosphorus content of shoots declined more rapidly. However, under the condition of phosphorus deficiency, there was no difference in the distribution of phosphorus among root and shoot of wheat cultivars with different P efficiency. The results showed that under the normal conditions of phosphorus supply, the phosphorus concentration in leaves of phloem-efficient wheat was lower than that of phloem, while that in phosphorus-deficient cultivars was higher. However, after the beginning of phosphorus deficiency, the phosphorus concentration in phloem sap of the high-phosphorus-efficiency cultivars decreased slowly, resulting in a higher relative phosphorus concentration. Ten days after phosphorus deficiency, the phosphorus concentration in phloem sap of leaves of low-phosphorus-efficiency cultivars was 35.9% of the control, while the phosphorus concentration in phloem sap of leaves of high-phosphorus cultivars was 59% of the control.