Studies On Interspecific Hybridization Technology And Irradiation Biological Effect Of Parthenocissus Tricuspidata And Parthenocissus Quinquefolia

The research covered two aspects: one was the interspecific hybridization technology of Boston ivy(Parthenocissus tricuspidata) and Virginia Creeper (Parthenocissus quinqeufolia) and the analysisof their hybrid obstacle. The other involved the y -ray irradiation on them, the observation onmorphologic and physiologic response of Ml plants and the selection of variation. The results wereobtained as follows:(1)The blooming period of P. tricuspidata and P. quinquefolia were not fully coincident. There were difference on the morphology of their inflorescence, floret, stigma and pollen.(2)Pollen of inflorescence of P. tricuspidata and P. quinquefolia had viability and could germinate since blooming day and ld before blooming day, respectively. There was not distinctive difference on pollen viability and germination percentage between blooming florets and those near blooming in same inflorescence. The optimal time for style of P. tricuspidata accepting pollen was 2d after blooming, while the time for P. quinquefolia was ld after blooming. It can be deduced that the development of reproductive organs of P. tricuspidata and P. quinquefolia had dichoaamous phenomenon. It was suggested that emasculation should be conducted on blooming day or ld before blooming day and pollination should be done l~2d after blooming while making cross.(3)The germination percentage of pollen was low, but the pollen of P. tricuspidata and P. quinquefolia could germinate on the surface of their stigmas, respectively. Pollen tubes could grow into their styles. When making crossing with P. tricuspidata and P. quinquefolia, most pollen could not germinate on the stigma. Even if germinated, the pollen tubes showed some abnormity such as twinning, tip inflation and bursting. 2 ~ 48h after pollination, pollen tube was not founded in the style of mother parents. It can be concluded the cross-incompatibility was taken placed on the surface of stigma.(4 )The tolerance of different organs to γ-ray was not same. At the dose rate of 1 ~3 Gy/min, their tolerant capacity were ranked from high to low as: one year dormant plant > dry dormant seed >one year shoot> wet cold-stratified seed, their irradiation dose were suggested as 75- 100Gy, 50~100Gy, 30~50Gy, 30~40Gy, respectively.(5) The variation of Ml plants of P. tricuspidata and P. quinqeufolia irradiated by γ-ray was not rich and stable. The variations were observed as follows: plant dwarfing, leaf-shape variation, leaf-color variation, and so on.