Mysql table creation foreign key error solution

CREATE TABLE task_desc_tab
(
  id INT(11) PRIMARY KEY NOT NULL COMMENT 'Auto-increment primary key' AUTO_INCREMENT,
  <strong>taskname</strong> VARCHAR(200) NOT NULL COMMENT 'Task name',
  sqlname VARCHAR(20) NOT NULL COMMENT 'sql file name',
  params VARCHAR(5000) NOT NULL COMMENT 'Task parameters, in the format of a JSON string',
  updatetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT 'Update time',
  detail VARCHAR(3000) COMMENT 'Some description information of the task, just for notes'
)
 ENGINE = InnoDB
 DEFAULT CHARSET = utf8;

CREATE TABLE exec_plan_tab
(
  id INT(11) PRIMARY KEY NOT NULL AUTO_INCREMENT,
  <strong>taskname</strong> VARCHAR(200) NOT NULL,
  startdate DATE NOT NULL,
  enddate DATE NOT NULL,
  updatetime TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  CONSTRAINT exec_plan_tab_task_desc_tab_taskname_fk FOREIGN KEY (taskname) REFERENCES task_desc_tab (taskname)
)
 ENGINE = InnoDB
 DEFAULT CHARSET = utf8;