Abstract
Relations between the amount of growth hormone produced in the tip of coleoptile and the length of mesocotyl in the maize plant were studied. The results obtained are as follows: (1) The maximum amount of growth hormone was observed in the seedlings 5-days old at 24°C. (2) The length of mesocotyl was positively correlated with the amount of growth hormone (r=+0.84** p<0.001) (3) The mesocotyl length in the mostly varieties recently introduced from America was generally longer than that in the Japanease varieties (tropical flint), and the amount of growth hormone produced in the tip of coleoptiles was larger in the American varieties that in the Japanease ones.
