Pollination Biology Of Carya Illinoinensis Koch.

Carya illinoinensisKoch.(Juglandaceae) is a species of Carya nativeto Americancontinent,which is worldwide dried fruit and woody oil tree. The pollination characteristics of C.illinoinensis cultivated in Maoshan regions were studied based on the observation, sampling anddetermination of flowering. The flowering phenology, flower morphology, flowering process,insect visitors, stamen dispersing and stigma receptivity were examined in for2years. Theartificial pollination was applied to elucidate the breeding features of C. illinoinensis.Additionally, the pollen preservation methods were explored for breeding new cultivars of C.illinoinensis..The results are as follows:1.C. illinoinensis bud canbe divided into four types, leaf bud, floral bud, mixed bud anddormant bud.There are three forms of male floral bud: triangular, fusiform and accessorybud.Mixed bud has two types.The difference between them is whether the bud can developfemale inflorescence.2.Female flowers blooming season of‘Western’ can meet male flowers blooming season of‘Mahan’ and ‘Mochou’. Male flowersblooming season of ‘Western’ can meet female flowersblooming season of ‘Mochou’.Single flower pollen counts havesignificant difference betweendifferent cultivars.‘Pawnee’ is the most one and‘Zhongshan’is the least.Pollen can be accepted bythe stigma during the type H,V and一. The ideal pollen time is the type V and一. The reason ofdifferent fruit set rates between three types maybe is the difference of stigma development invarious degrees.The stigma matures gradually from inside to outside and top down.which keepswet until the end of the receptive period.3. C. illinoinensis is the typical wind-pollinated plant.The effective pollination distance of6years old tree (H:4m) is80-100m.The main pollinators are Lipaphis erysimi,Coccinellaseptempunctata and Polyrhachis dives,which are not obligate pollinators.4.Short term preservation can use the method of natural drying,under a constanttemperature of4℃.Long term preservation shoud be under a constant temperature of-70℃, anduse different drying methods.‘Mahan’ and ‘Mochou’ need oven drying under a temperature of35℃.‘Western’ needs natural drying.‘Pawnee’and ‘Zhongshan’ need drying agent.5. The results of the treatments of bagged without artificial pollination show that C.illinoinensis may have apomixes.C. illinoinensis owns a facultative mating system which mixesself and crossing compatibility via artificial pollination as well as OCI examination,butself-fertilize may aggravatefruit drop.In the study of interspecific hybridization, the femaleparents are ‘Western’and ‘Mochou’, while C.cathayensisused as the male parent.The resultsshow that there is no reproductive isolation between C. illinoinensisand C.cathayensis.But theaffinity had significant difference between C.cathayensisand some cultivars of C.illinoinensis.Pollenating withbrushis suit for scientific researchbecause of its high fruit set rate.Sprayingpollen solution(pollen∶water=0.5∶1000) can save time and effort,which is suitfor production practice。6. We monitored pollen germination and the course of pollen tube growth of selfcross andoutcross of ‘Mochou’, intraspecific hybridization and interspecific hybridization by means offluorescence microscope. The results show that these treatments have little effect on pollengermination and the course of pollen tube growth. Once the external pollen was distinguished bythe stigmas of ‘Mochou’ and ‘Western’, the pollen would germinate in1-2hours and fertilized inabout10-12hours.