The Study On The Effect Of Polyamines On Flower Development Of Litchi

Litchi flowers are regulated by many factors.In this experiment,the effects of polyamines on the flowering process of litchi were studied.First,in the field experiment,leaves of the three cultivars ‘Guiwei',‘Huazhi' and ‘Nuomici' were used to analyze the content of mineral elements,polyamines and soluble protein in the leaves were studied to explore their relationship with flowering.In the greenhouse,the ‘Feizixiao' cultivar was selected as materials.There were three treatments in this experiment,T1(25? 49 d),T2(25? 14 d + 15? 35 d)and T3(25? drought 14 d + 15? 35 d).The changes of arginine and polyamines in the leaves were measured,and the genes related to polyamine synthesis were quantified.The effects of polyamines on the induction process of litchi were studied.The main results were as follows:(1)The content of Ca in the leaves of different varieties of litchi was different,and the content of Ca in the ‘Guiwei' cultivar was significantly higher than that in the other two cultivars.With the development of the flower.Putrescine content and spermidine content in leaves increased first and then decreased,and reached the highest at 7 d(flowering stage),whereas at the branch without flowers,their content did not increase obviously,while increased in the later stage,indicating that the development of flowers needed high level of polyamine.(2)In the greenhouse,T1,T2 and T3 treatment had significant differences in flower biology.Trees in T1 did not flower,and the flowering rate of T2 and T3 reached 100%.However,the flowering shoot rate of T3 was 100% and that of T2 was 75%.Compared with T2,T3 treatment could flower about 7 days earlier,the flower panicle length increased by 28.7% and the flower panicle width increased by 67.6%,indicating that drought stresscould promote the growth of litchi flower.(3)The content of arginine decreased and the content of putrescine increased rapidly after drought stress treatment,which indicated that drought stress promoted the synthesis of putrescine.In the process of low temperature induction,the content of arginine decreased first and then increased,and the content of putrescine increased first and then decreased.The content of spermidine and the content of spermidine decreased,indicating that polyamines may be involved in the process of litchi flowering,but the specific mechanism is not clear.(4)Lc ADC,Lc SPDS1,Lc SPDS2,Lc SAMDC1 and Lc SAMDC2 were screened and cloned in the litchi genome and transcriptase by other plant polyamine synthesis gene sequences.Through biological information analysis,they have higher homology with other plants,and have their symbolic elements of the gene family.