Study On The Distant Hybridization Of Pollen Germination Between Tree Peony Cultivars And Peony Cultivars, And Morphological Of Embryonic Development

In this paper, The test of distant hybridization between tree peony and herbaceous peony, The cultivar of Paeonia lactiflora ’Fenyunu’, Paeonia ostii ’Fengdanbai’, Paeonia suffruticosa‘Luoyanghong’ were used as parents, and Paeonia lactiflora’Fenyunu’ were used in all crosses as the female parent, and Paeonia ostii ’Fengdanbai’, Paeonia suffruticosa‘Luoyanghong’ were used as the male parent. The research identified the characteristics and law of flower bud differentiation of parents, researched the germination characteristics and optimal culture medium of pollen and the ultramicroscopic structure of pollen and stigma, and the differences between different cultivars, selected some feasible controlled pollination methods of each cross, researched the main factors and overcoming methods for cross-incompatibility, The main results were as follows:1.The bud of tree peony and herbaceous peony are mixed buds, the flower bud differentiation of tree peony lasted about 100 d, the bract primordium differentiation since early June, sepal primordium differentiation since late June, petal primordium differentiation started from July, the stamen primordium differentiation started from mid to late August, pistil primordium differentiation since mid-september. The flower bud differentiation of herbaceous peony lasted about 140 d, bract primordium differentiation since mid-september, sepal primordium differentiation begins in early October, petal primordium started from the mid to late October differentiation, stamen primordium from in late January of the next year differentiation, pistil primordium differentiation from the early February.2.Pollen germination rate and pollen tube elongation were a downward trend with the increase of storage time, but the decline of pollen tube elongation was not obvious, and the influence to the pollen germination rate was not obvious in different culture mediums, while showed the different functions for pollen tube elongation scale, and the biggest pollen tube elongation of ‘Feng dan bai’ was 10% sucrose + 50 mg/Kg boric acid + 60 mg/LCa Cl2 solution, the biggest pollen tube elongation of ‘Luo yang hong’, ‘Fen yu nu’ was in 10% sucrose + 50 mg/Kg boric acid + 40 mg/LCa Cl2 solution.3.The parents has the similar structure type on pollen grain, the shape of pollen grain is spherical, with two germination ditch, their pollen grains has small differences in the size and shape, but the surface of pollen grain showed the conspicuous differences, the morphological structure of stigma was similar, and showed conspicuous differences in the shapes and fine stucture, The spherical protrusions on the stigma surface of three male parent was lesser and more obvious while the spherical protrusions of female parent ’ Fen yu nu ’ was bigger and more vague.4.In the cross of P. lactiflora’Fenyunu’× P. ostii ’Fengdanbai’,the method of delayed pollination and the repeated pollination had bypassed the pre-fertilization barriers, In the process of fertilization, germinated pollens were much observed on stigmas,the pollen tubes passed on the total length of the styles, and protruded to the ovary can observed by the fluorescence microscope. For P. lactiflora’Fenyunu’× P. suffruticosa‘Luoyanghong’, the method of mentor pollen pollination and the delayed pollination are suitable for bypassing pre-fertilization barriers, The quality and quantity of pollen germination and growth of the pollen tubes were largest, and pollen tubes which were protruded to the ovary can found partly. Compared with the selfing of P. lactiflora’Fenyunu’, the germinated pollens and the yield of pollen tube length were more less.5.0d ~ 20 d after pollination, two hybrid combinations carpel developed normally, obviously increase, a smaller ivory ovule, 20 d after the vast majority of carpel occur gradually atrophic, ovule gradually atrophic in black, carpel open at 100 d, not abortive ovules develop into dark brown seeds; Combination of selfing after pollination, carpel developed normally, when the 40 d ovule enlargement, 100 d, carpel is dark brown, seed is dark brown.6. After pollination, watch the hybridization combination of embryonic development, found that 10 d ~ 20 d after pollination, the vast majority of the fertilized egg of disintegration of the abnormal phenomenon, has been observed in the later observing normal embryonic development process; After self pollination, the vast majority of normal embryonic development, can be observed in the complete process of embryonic development;In hybrid combinations, P. lactiflora’Fenyunu’× P. ostii’Fengdanbai’ setting percentage is 4.13%, P.lactiflora’Fenyunu’× P. suffruticosa‘Luoyanghong’ setting percentage is 3.14%, the selfing of P. lactiflora’Fenyunu’ setting percentage is 68.34%, the cross combinations is much higher than the hybrid combinations.