Effects Of Exogenous Hormones On Regulation Of Flowering Period Of Rapeseed (Brassica Napus L.)

Rapeseed is one of the important sources of edible oil in the world and has important practical value.The flowering period of rapeseed is the premise of high-yield,stable-yield and high-quality germplasm,and it is an important agronomic trait.Therefore,it is of great theoretical and practical value to study the regulation mechanism of flowering period and its induction pathway.In this study,Brassica napus L.,"Wancheng No.1" and "Wanhong No.1" were used as materials to study the effects of different exogenous hormone treatments on the flowering period and growth characters of Brassica napus;The regulation mechanism of flowering period and the expression of flowering-related genes of Brassica napus under the treatment of oxalic acid and uniconazole,the differential genes related to flowering were screened by transcriptome sequencing technology,and the expression of differentially expressed genes related to flowering was verified by q PCR.The main results are as follows:1、The flowering and growth characters of "Wanhong 1" were better than those of "Wancheng 1" after treatment with different exogenous hormones.GA treatment promoted flowering,significantly advanced the first florescence,and the effect of prolonging florescence days was the most significant,up to 6.67 days,showing a significant increase in plant height;PP333 treatment inhibited the differentiation of flower meristem and delayed the initial flowering stage.With the increase of concentration,the inhibition effect was more obvious,showing plant dwarfing.2、Gibberellin and Uniconazole significantly affected the endogenous hormone content in the shoot tip,and then affected the growth,development and physiological characteristics of rapeseed by regulating the change of endogenous hormone content.GA treatment mediated the increase of endogenous GA and CTK contents,and then promoted the growth and differentiation of rapeseed organs,the growth of bolt length and plant height,and the early flowering stage was advanced;Uni treatment inhibited the increase of Endogenous IAA content,increased ABA and CTK content,inhibited bolt length and plant height,and delayed the initial flowering stage.In addition,by regulating the content of endogenous ABA and CTK,the decline of photosynthesis was delayed and the degradation of chlorophyll was inhibited.3、Using transcriptome technology,147 flowering related differentially expressed genes were screened,of which 98 genes were significantly up-regulated and 102 genes were significantly down regulated.Most of the key factors involved in apical meristem response pathway,gibberellin signal transduction and metabolic pathway,as well as vernalization pathway,photoperiodic pathway and other key factors.4、Bn FLC.C02 was significantly up-regulated in Uni treatment;Bn SOC1.A04 was significantly up-regulated in GA treatment.Bn GA20OX3 and Bn GA2OX1 control GA synthesis and metabolism.Bn GA20OX3 is up-regulated in GA treatment,which may cause changes in endogenous GA,promote GA synthesis,and show early flowering;at the same time,Bn GA2OX1 is up-regulated in GA+Uni and inhibits GA activity,which may lead to The decrease of endogenous GA content showed late flowering.