不同生长年限紫花苜蓿磷的积累与分配规律

Phosphorus accumulation and distribution in different age alfalfa

以2龄、3龄、4龄、5龄和7龄紫花苜蓿Medicago sativa为试验对象,研究了紫花苜蓿磷的积累与分配规律。结果表明,紫花苜蓿地上部分的磷含量,随着生育期的推移先降低后略有升高,随着生长年限的增加而持续降低,成熟期的磷含量总体上表现为:叶>生殖器官>茎。随着生育期的推移,紫花苜蓿地上部分磷的积累量持续增加,积累速率先升后降。不同生长年限紫花苜蓿成熟期各器官磷的分配比例平均为:茎(64.7%)>生殖器官(23.7%)>叶(11.6%)。紫花苜蓿茎中磷的分配比例随生长年限的增加而升高;叶中磷的分配比例则随生长年限的增加而降低;生殖器官中磷的分配比例以2龄紫花苜蓿最高,7龄紫花苜蓿最低。

Phosphorus accumulation and distribution were studied on 2-, 3-, 4-, 5- and 7-year-old alfalfa. The results showed that content of phosphorus in above-ground parts decreased during the whole growing seasons except increased little in the late, and decreased as plant ages increased. Content of phosphorus increased as order as leaves, reproductive organs and stems in maturing stage. As the plants growing in a year, phosphorus in above-ground parts increased, while accumulation rates increased firstly and then decreased. Phosphorus in the matured tissues was 64.7% in stems, 23.7% in reproductive organs, and 23.7% in leaves in all ages. For different ages of plants, phosphorus increased in stems and decreased in leaves as ages increased. Percentage of phosphorus in 2-year-old reproductive organs was highest, and in 7-year-old was lowest.