Oil Palm(elaeis Guineensis Jacq.)Pollination Biological Characteristics And Expression Analysis Of The Related Genes

Pollination is the basis for the formation of fruit yield.The research of pollination biology characteristics of oil palm can provide theoretical basis for increasing its production.The germination of plant pollen and the growth of pollen tube are extremely complex processes,with many genes involved in the regulation of these.However,there was less research about this area.The external morphology of male and female flowers of oil palm was observed in this article.The pollen viability was detected by pollen germination in vitro.The pollen morphology was observed by scanning electron microscopy.The stigma receptivity were detected by benzidine-hydrogen peroxide method.The relative expression of related genes in pollen before and after germination and the relative expression of the female flowers of the related genes at different time points after pollination was analyzed by real time fluorescence quantitative PCR technique.The related genes include GPI(glycosyl phosphatidyl inositol,control glycosylphosphatidyl inositol synthesis),MYB transcription factor and so on.The results of the study were as follows:(1)Male inflorescence is composed of fingerlike spikes,the length of each flower spike is 7?20 cm,diameter is 0.8?1.5 cm,male flowers are borne on the spike.There are 6 anthers in each bud,2 rooms in the anther,and the intermediate is divided by the drug septum.The female inflorescence is composed of spikelet,each spikelet has 6?40 flowers,which is spirally arranged on the spikelet.The female inflorescence can be divided into 5 periods according to its development process,phase I(show flowering period,1?2 d before flowering);Phase II(early flowering,the first day of flowering);Phase III(Y stage,2?3 d after flowering);Phase IV(roll period,4-5 d after flowering):wide angle and apical lobes,rolled;phase V(wilting period,6-10 d after flowering):brown color.(2)The results showed that the first day of male inflorescence powder had strong pollen vigor.The pollen viablity strongest period of Pisifera,Tenera and Dura is the fourth,second and third day after pollen dispersal,respectively.Pollen viability changes of Tenera and Dura within 1 d were not obviously,but in Pisifera,showing the trend of the afternoon>morning and pollen viablity is the strongest at 14:00 in the afternoon.The pollen grain numbers of single anther of different types of oil palm were about 5000-8500.By scanning electron microscope,we can see that the pollen morphology of three types of oil palm exists in the form of single grain shape,smooth edge of the triangle,the length of side in 32?34?m.The outer wall has a fine reticulate ornamentation,a shallow hole or an irregular small perforation.With 3 grooves,the net ornamentation around the germinating holes is thinner.(3)The determination of stigma receptivity by benzidine-hydrogen peroxide method.The results showed that the stigma receptivity of the 3 types of oil palm was weak at the first stage,and the Pisifera and Tenera were the strongest at the III stage.The stigma receptivity of Dura was the strongest at the IV stage.The stigma receptivity of Pisifera and Tenera showed the trend of morning>afternoon and the strongest time was 10:00.Nevertheless,the stigma receptivity of Dura showed the trend of afternoon>morning and the strongest time was 16:00.(4)The GPI was expressed in the oil palm pollen before germination of Dura and Tenera.But there was no expression of that at 3 h after germination.The case in the Pisifera was the opposite.The GPI-anchored was expressed in the three types oil palm pollen before and after germnation and.the relative expression of down-regulation after germination was than before.The MYB was expressed in the three types oil palm pollen before germination,but after the germination of pollen,only in the Dura was expressed.The MYB(x3)was expressed in the three types oil palm pollen before and after germnation.The relative expression of Dura pollen before and after germnation was the same.The relative expression of down-regulation after germination was than before in Tenera.The relative expression of up-regulation after germination was than before in Pisifera.(5)The GPI was expressed in oil palm female flower at 0 h and 24 h after pollination of Tenera and Pisifera.The relative expression of up-regulation at 24 h was than 0 h after pollination in Tenera.The relative expression of down-regulation at 24 h was than 0 h after pollination in Pisifera.However,there was no expression at 0 h after pollination and there was expression at 24 h after pollination of Dura.The GPI-anchored,MYB6,MYB(x3)and MYB39 were all expressed in female flowers at 0 h and 24 h after pollination of three types oil palm.