Comparative Study On Pollination Biology Of White Flower Platycodon Grandiflorum And Purple Flower Platycodongrandiflorum

Platycodon grandiflorum (Jacq.)A.DC is a perennial herbaceous plant of campanulaceae and atraditional Chinese medicine in our country. Its dry root is used as medicinal materials, tastes bitter,acridity, and gentle nature. It has the effect of diffusing the lung, relieving sore throat, apocenosis andexpelling phlegm. Used for cough phlegm, pulmonary abscess vomit pus, bosom frosty, sound dumb,sore throat, etc. It is an economic plant that is used as medicine, food and ornamental plant. In this paper,conducted and analyzed the flowering phenology, reproductive biology and pollination biology of whiteP.grandiflorum and purple P.grandiflorum. The results were as follows:â'ˆContrasted the flowering phenology of white P.grandiflorum and purple P.grandiflorum, theresults showed that the individual flowering phase of white P.grandiflorum and purple P.grandiflorumwere (26.17±2.69) day and (30.33±2.0) day, and their single flower phase were (5.8±0.31) day and(6.2±0.15)day, respectively，and their groups flower phase were35day and47day, respectively. Whiteflower P.grandiflorum group first-flowering dates earlier2days than purple flower P.grandiflorum andgroup final-flowering dates later14days than purple flower P.grandiflorum.Both of the floweringprocess were unimodal curve, and had a high coincident index, but they had a low level of the floweringintensity. There were significant differences in the total flower number, flowering amplitude, peakflowering date, last flowering date and fruit set of P.grandiflorum and purple P.grandiflorum, but therewere no significant differences in the synchrony index first flowering date, flowering duration and fruitset number of them.2. Contrasted flower characteristics and breeding characteristics of white P.grandiflorum andpurple P.grandiflorum, the two groups of P.grandiflorum have obvious difference in corolla color,stigma color and filaments color. The results showed that there were no significant difference betweenthem including the length of corolla, the width of ovary, the length, width and depth of flower lobes, thelength of stamens and the length of pistil except for Corolla wide. In the process of flowering, they havethe same variation trend in pollen vitality and stigma receptivity. Both of the pollen vitalities could to bemaximized in the first flowering day and their pollen life is3days, the highest of their stigmareceptivity is in the second day. Pollen storage at room temperature, room temperature dryer and4℃all can prolong its life, and the4℃storage effect is best, pollen life can reach15days. The ovule ratioof white P.grandiflorum and purple P.grandiflorum were2282.3and2195.1, respectively, and both ofhybrid index were five. The results of artificial pollination showed that P.grandiflorum have nophenomenon of apomixis, it can self-pollination, self-compatible and outcross-compatible.According tothe two P.grandiflorum groups of P/O, OCI and pollination experiment prove their all belong to selfingand outcross mixed mating system.3. Contrasted the pollen spread rule of white P.grandiflorum and the purple P.grandiflorum, thewind pollination distances of white P.grandiflorum and purple P.grandiflorum were1.5m and0.8m,respectively, and the number of pollen with distance increase first increase then decrease. The results showed that the flower-visiting insect have bees, hymenoptera and butterflies, etc. The most majorpollinators were honeybee and scoliid. The pollination frequency of P.grandiflorum inflorescence waslower than others, during the day, the pollination peak was persisted between10:00am and15:00pm,the highest pollination frequency of white P.grandiflorum was farther than purple P.grandiflorum were26times/(inflorescence· h-1) and28times/(inflorescence· h-1).The pollination distance of whiteP.grandiflorum was farther than purple P.grandiflorum by insect, which were9.8m and6.5m,respectively, and their detection of staining of pollen were more in4m.. Using ISSR markers for thepollen flow measurement of P.grandiflorum showed that the effective propagation distance of whiteP.grandiflorum and purple P.grandiflorum were7m and6m, respectively.