EXUDATION OF AN ALLELOPATHIC SUBSTANCE LEPIDIMOIDE FROM SEEDS DURING GERMINATION

Lepidimoide promotes growth of the cockscomb hypocotyl. It is exuded f rom germinating seeds of various plant species into their culture envi ronment. The mode of exudation of lepidimoide from seeds into the cult ure solution, using sunflower and buckwheat seeds, was studied in rela tion to seed germination. In the dry seeds, about 75% of the lepidimoi de was found in the seed coat and about 25% in the kernel. Upon water imbibition it was released into the culture solution. However, the qua ntity of lepidimoide detected in the seed exudate was more than three times the total amount in dry and imbibed seeds, suggesting that lepid imoide was also produced de novo in the seeds and subsequently release d. When seed coats or kernels were imbibed separately, the quantity of lepidimoide released from the seed coats into the culture solution wa s much the same as that in the dry seeds, but the amount of lepidimoid e detected in the exudate of kernels was about 16 times that in the dr y kernels. These results suggest that lepidimoide, already present in dry seeds, as well as that newly produced in the kernels following imb ibition, was released into the environment.