Effect Of Growth Regulator On Endogenous Hormones In Wheat And Maize

Growth regulator and its related chemical control technology has become an important supporting cultivation technique for cotton,fruits and vegetables and some grain crops.In this paper,we sprayed a combined growth regulator(an invention patent of our team)on the leaves of wheat at beginning of tillering and different concentrations of 6-BA solution(0mg/L?50 mg/L?100 mg/L?200 mg/L?400 mg/L and 500 mg/L)on the leaves of maize after silking stage planted in field plot,to observed the effect of different regulators on the numer of tillers and biomass of wheat,endogenous hormones in three parts of wheat(leaf,leaf sheath and root)and two parts of maize(ear leaf and fruit kernel).The results showed that:(1)After spraying the combined growth regulator14 days(2 days before the winter solstice),the content of growth hormone(IAA)in the leaves decreased,the content of 6-BA increased;the content of abscise acid(ABA)decreased,but the content of gibberellin(GA)did not change much.And the contents of GA and IAA in leaf sheath decreased,the contents of 6-BA increased,and the contents of 6-BA in root system increased,but the contents of GA did not change much.After spraying growth regulator 28(2 days before minor cold)and 35 days,the content of IAA and GA in leaves was decreased,and the content of 6-BA and ABA was increased.The contents of IAA and GA in leaf sheath decreased and the contents of6-BA increased.GA content in root increased,6-BA content increased but the rate decreased.Form the 7th day after spraying,tiller number,aboveground biomass and total biomass of winter wheat began to increase gradually,and reached a significantl level at the last stage,while underground biomass did not change much.(2)After the spraying of 6-BA solution with different concentrations 7 days(early stage of grouting),the contents of IAA and 6-BA and Zeatin(ZT)in the ear leaf of maize were significantly increased,the contents of IAA?6-BA and ZT were higher at the spraying concentration of 100 mg/L.After the spraying of 6-BA solution 14 days,the contents of IAA,6-BA and ZT in the ear leaf of maize were significantly increased,and the contents of IAA were the highest when the spraying concentration was 100 mg/L,6-BA and ZT content was the highest when the concentration was 100 mg/L.After 21 days of spraying,the content of6-BA and ZT was significantly increased,and the content was the highest when the spraying concentration was 100 mg/L.After 28 days of spraying,hormone content was no significant increase in the ear leaf of maize.With the increase of time after the spraying of 6-BAsolution,ABA content were gradually increased and GA content were gradually increased in the ear leaves of maize,while the contents of IAA and 6-BA and ZT were increased at first and then decreased,the contents of ZT reached the peak after the spraying of 14 days,IAA and 6-BA reached the peak after the spraying of 21 days(middle stage of grouting).(3)After spraying 6-BA solution,the content of IAA in corn seeds was significantly increased,and the content was the highest at the spraying concentration of 100 mg/L.The content of ZT was significantly increased at 7 days and 14 days after spraying.The content of 6-BA was significantly increased at 28 days after spraying,and the content was the highest at the concentration of 100mg/L.ABA content significantly increased after 28 days of spraying(at the later stage of grouting),with the highest concentration at 100 mg/L.No significant increase in GA content was observed after 6-BA spraying.With the increase of time after spraying 6-BA solution of different concentrations,ABA content in seeds increased gradually,GA content decreased gradually,IAA and CTK content increased first and then decreased,IAA content reached the peak 14 days after spraying,ZT and 6-ba content and their total content reached the peak after spraying 21 days.In summary,spraying compound growth regulator before winter wheat tillering can reduce the content of IAA,increase the content of 6-BA in leaves and leaf sheaths,and increase the content of GA and 6-BA in roots,which is conducive to the generation of tillers and increase in aboveground biomass,and to some extent promote the growth of underground roots.In the early stage of tasseling,spraying 6-BA with a concentration of 100mg/L could effectively regulate the metabolism and balance of endogenous hormones in leaves and grains,thus improving the grain yield.