| The experiment was conducted to study the changes of endogenesis hormones in the top fourth leaf of cotton during seedling to full flowering stage,and analyze the relationship between hormones and different positions.The results showed: The content of IAA tended to be decreased in the early stage,but went up after the full flowering stage;The content of CTK presented the tendency of rising along with the growth of cotton;In flowering and boll developing stage,the content of GA3 tended to be dropped,and the variation trend of GA3 in leaves and in buds was opposite;There was a time difference between the peak value of ABA in leaves and that in buds.In leaves,the change tendency of each hormone ratio was similar to that of nutrient N and K in the squaring stage;In stems,there was a time difference between the change tendency of each hormone ratio and that of nutrient N and K;In flowering and boll stage,the change tendency of each hormone ratio was similar to that of N in nutritive organ,but was opposite to that of K.The content of P in cotton was not notably influenced by the changes of hormone ratio. |