The Selection Of Filial Generations Between AtDREB1A Transgenic Ground Cover Chrysanthemum And Conventional Varitey

Ground cover Chrysanthemum are cultivated in gardens and greenbelts world-wide with good 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 tolerances, hence, supply fundamental materials and theory foundation for the further selection. The purposes of these experiments are to obtain material of new ground cover chrysanthemum cultivars with great phenotype and stress tolerance, and to provide theoretic basis and actual basis for combination of gene engineering breeding and conventional cross breeding of ground cover Chrysanthemum.The cross breeding method of non-emasculation artificial pollination was used, transgenic plant'Fall Color'integrated AtDREBIA gene as the female parent, the better ornamental and widely used cultivars as the male parents,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 bud sprout,and presume that low tempreture tolerance of transgenic hybrids are improved.PCR analysis 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:land 6:1.Based on classification standard of ground-cover chrysanthemum cultivars character, combined chrysanthemum bodies (including growth vigor, plant height, crown width), flower, resistance etc. and integrated evaluation of 384 filial generations,the better ones were selected as the further test materials(A-38,A-112,A-136,B-25,C-48,D-82.).PCR analysis of progenies demonstrate that exogenous gene can be transferred to the filial generations by sexual reproduction and asexual reproduction. Tissue culture transgenic hybrids and wild type plantlets were exposed to 30℃for 8 days water withheld and followed by a 2 weeks normal watering process and 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. RT-PCR analysis revealed that DREB1A gene was over-expressed constitutively in 35S:DREB1A Plants, but was inductively in rd29A:DREB1A plants.When exposed to cold, dorught stress conditions,DREB1A gene expression was enhanced in young plant of transgenie 35S:DREB1A filial generations, and induced obviously in that of transgenic rd29A:DREB1A filial generations. Over-expression of AtDREB1A conferred strong tolerance to cold and dehydration stresses not only in chrysanthemum transgenic plants,but also in transgenic hybrids.