Effects Of Short-Day Treatment On Floral Bud Differentiation And Flowering Of Ground-Cover Chrysanthemum 'ZiJiao'

The experiment was conducted to study the effects of short-day treatmen(0d,30d,50d)on floral bud differentiation and flowering stage of ground-cover chrysanthemum 'ZiJiao'.The changes of physiological indexes,morphological indexes and the expression of flowering genes in the process.Provide theoretical basis for the annual production of Chrysanthemum.The main results are as follows.1.Floral bud differentiation stage of 'zijiao' was divided:Inflorescence differentiation:Vegetative growth stage;Inflorescence primordial differenti ation stage;Initial stage of involucres primordial differentiation;Final stage of involucres differentiation;Initial stage of ligulae flower differentiation;Final stage of ligulae flower p rimordial differentiation.Floret differentiation:Initial stage of the corolla formation;Second stage of the corolla formation;Finish stage of thr corolla formation2.Shorten the time of flower bud differentiation and advanced flowering in 30d and 50d short-day treatment.And inhibition of plant height and crown width and number of f'lowers.With the short-day treatment time extended,the inhibition is increased.Partial abnormal buds appeared in 30d short-day treatment.And flowering two times in 30d short-day treatment,but the number of single flower is small.3.1n the process of flower bud differentiation.Soluble sugar content was first rises and then declines of all treatments.But the soluble sugar content was the highest in the inflorescence primordial differentiation stage of control group.And the highest in the involucres primordial differentiation stage of 30d and 50d short-day treatment.Soluble protein content was dropping at first to rising afterwards of all treatments.But the soluble protein content was the lowest in the involucres primordial differentiation stage of control group.And the lowest in the ligulae flower differentiation stage of 30d and 50d short-day treatment.The control changes earlier4.Visible bud to the late flowering stage.The contents of soluble sugar in leaves of control and the second flowering of 30d short-day treatment were the same.The highest in the appear color stage.The lowest in the full blooming stage.The contents of soluble sugar in leaves of 50d short-day treatment and the first flowering of 30d short-day treatment were the same.The highest in the visible bud stage.The lowest in the initial blooming stage stage.Visible bud to the late flowering stage.The soluble protein content in leaves of control and the second flowering of 30d short-day treatment were the same,But with the first flowering of 30d short-day treatment and 50d short-day treatment is different.Difference in performance:The former highest in the full blooming stage,Decreased from visible bud stage to full blooming stage.Late flowering stage rose.The latter highest in the initial blooming stage.The full blooming stage and the late flowering stage decreased.5.In the process of flower bud differentiation.CmCOL1 gene appeared two times high expression of 50d short-day treatment and the first flowering of 30d short-day treatment.Control group appears high expression in initial stage of involucres primordial differentiation.CMGI2 gene appeared three times higher expression.The expression of CmGI2 gene in 50d short-day treatment and the first flowering of 30d short-day treatment was higher than that in control group.CmFT gene expression increased in magnitude and the highest value in advance,and there were two high expression in 50d short-day treatment and the first flowering of 30d short-day treatment.The expression patterns of CmFT,CmPRR2,CmPRR7,CmPRR37 and CmPRR73 genes are similar.The expression is at a lower level in vegetative growth stage,inflorescence primordial differentiation stage and involucres primordial differentiation stage.After entering the ligulae flower primordial differentiation stage,the amount of expression began to increase.CmPRR7 gene expression decreased rapidly when entering the corolla formation.But CmPRR37,CmPRR73 gene expression reached the highest when finish stage of thr corolla formationThe expression of CmGI2 and CmPRR37 gene was higher than that of the control in 50d short-day treatment and the first flowering of 30d short-day treatment.And CmPRR2 gene expression increased earlier.And the highest expression level of CmPRR7 and CmPRR2 was higher than that in the control group.CmFT,CmPRR2,CmPRR73 gene rise in 50d short-day treatment and the first flowering of 30d short-day treatment is faster than the control.