Preliminary Study On Pollen Dispersal And Fruiting Characterstics Of Dahlia

Dahlia pinnata Cav is a perennial bulbous flower in the genus Dahlia,which have the most types in the world.It's flowers are big.various and colorful.One of the most world's famous flowers,widely cultivated in application.Preliminary study on breeding characteristics in Dahlia provide basic theoretical guidance for the future development of hybrid breeding of Dahlia.This study preliminary explored suitable culture medium for Dahlia pollen in vitro germination and storage characteristic,then variation anlysis for the quantity and germination characteristics of pollen,and their relationship with seed setting rate was carried out on different cultivars of Dahlia resuorce.The result showes that:(1)Pollen germination was examined in vitro to select the opitimal medium.It was found that the opitimal medium was 0.01%H3BO3+0.03%Ca(NO3)2·4H2O+4%sucrose+0.02%MgSO4·7H2O+0.01%KNO3.The pollen of 'Baisepengpeng','Ying535' and' Saishanghualang'were preserved in different temperature(room temperature,4 ?,-20 0C,-80 0C)then detected pollen germination.The result showes that:the germination rate of pollen preserved at temperature for 7days,4 ? for one month,-20? for30 days,-80? for 25days,the pollen persered at 4 0C performanced better than-20??-80 ?.(2)Examined pollen germination and pollen quantity,the result shows that;significant various on the quantity of total pollens and germination rate were observed among the different genotypes,which were estimated to be 18.3?176 disk floret per inflorescence,190?6480 grains per anther,'Niunai kafei,has the most pollen quantity,'Douniuwu'has the least pollen quantity.Averge pollen quatity per anther is 2726,1.74 ten thousand?313.3 ten thousand perinflorescence;there were 2 cultivars of Dahlia 'Douniuwu'' and 'Qifei'the apparent pollen quantity are none.Pollen germiantion was examiend to be 0-45.17%,average pollen germination is 19.16%.Culstering analysis was applise the pollen germination and pollen quantity to three cluster,almost cultivars of Dahlia wtih more pollen quantity but low pollen germiantion,(3)The result of investigation seed setting rate shows that:the seed setting rate of more than 50%cultivara of Dahlia is 0.only 28 had seed,seed setting rate to be 0.01%?10.26%,the seed setting rate of 'Baise pengpeng ' was higest,'Chengsefobuji'was lowest.The average seed setting rate was 2.15%,the seed setting rate of 16 resource Dahlia were lower than 0.01%,so that we guss that most Dahlia are self-incompatibility.Ariation anlysis for the quantity and germination characteristics of pollen,and their relationship wtin seed setting rate was carried,the result shows that seed setting rate is closely related to pollen germination,and seed setting rate independent variable to pollen quantity.Pollen germiation is closely related to pollen germination,loose powder characteristics,flower form.