The Selection And Breeding Of Filial Generations Between DREB1A Transgenic Ground Cover Chrysanthemum And Conventional Varitey

Ground cover Chrysanthemum are cultivated in gardens and greenbelts world-wide with better ornamental and tolerance to extensive management.But,the sensitivity of this cultivar to cold and dehydration stresses have been the key factors limiting its cultivation in northern china.In this study, we are aiming to obtain Chrysanthemum with better ornamental and multiple tolerance, hence, supply fundamental materials and theory foundation for the further selection.The cross breeding method of non-emasculation artificial pollination was used, transgenic plant'Fall Color'integrated AtDREB1A gene as the female parent, the better ornamental and widely used cultivar 'Asia Winter Light' as the male parent, 384 filial generations grown and developed well.The characters present comprehendsive segregation,such as height,crown and flower color.Via simple protection of 2007 winter, filial generations overwintering in open-field better than the wild type. We also discovered many on the floor buds sprout,and presume that low tempreture tolerance of transgenic hybrids are probably improved.PCR analysis of some filial generations demonstrates that exogenous gene can be transferred to the filial generations by sexual propagation.Via the sexual propogation, separation rate of exogenous gene are different,between 2.9:1 and 6:1.Under dehydration, physiological characteristic indicates that the wild type is different with the transgenic hybrids which carrying exogenous DREB1A gene. Tissue culture transgenic hybrids and wild type plantlets were exposed to 30℃for 12 days water withheld and followed by a 2 weeks normal watering process, survival rate of parts of transgenic hybrids were higher than the wild type.The capacity to adapt drought condition of transgenic hybrids is stronger than the wild type except rare plantlet,this probably relevant with the existence of exogenous gene and expression pattern.Under low tempreture, physiological characteristic indicates that the wild type is different with the transgenic hybrids which carrying exogenous DREB1A gene. Compared to the wild type,germination rate of transgenic hybrids T₁ seeds and growing of cuttage propogation plantlets are better.Tissue culture transgenic hybrids and wild type plantlets were exposed to a temperature of -10℃for 10h and followed by a 2 weeks recovery process, survival rate of transgenic hybrids were higher than the wild type,and transgenic hybrids grown better in open-field than the wild type.Overall,the capacity to adapt low tempreture condition of transgenic hybrids is stronger than the wild type, Phenotype is relevant to the physiological expression.Over-expression of AtDREB1A conferred strong tolerance to cold and dehydration stresses not only in chrysanthemum transgenic plants,but also in transgenic hybrids. Using cuttage propogation method,rooting rate and transplant survival rate of transgenic hybrids were high,transgenic hybrids grown and developed well.Compared with the wild type and parents, many characters such as the height,crown,stem width, leaf area,inflorescence, flower head diameter,flower quantity of the transgenic hybrids present phenotypic difference.