| The flower bud differentiation was the foundation for two-crop-a-year cultivation of grape.In order to study the effects of different regulation measures on the flower bud differentiation process and flowering rate of the winter buds of grape,eight-year-old grape cv.'Summer black' grape cultivated under two-crops-a-year mode were used as study material.There were 4 treatments:different summer pruning(pinched at 2,4 and 6 nodes above the anthotaxy)and spraying of the different growth regulators(6-Benzylaminopurine(6-BA):50,100 and 200 mg/L,Chlormequat chloride(CCC):0.3,0.5 and 1.0 g/L;Ethephon(ETH):200,400 and 800 mg/L).The 4th to 9th node buds were sampled weekly when the shoot was under the 5-7 leaf stage,and were made paraffin sections to observe and statistically analyze the flower bud morphological differentiation process and flowering rate.Meanwhile,the contents of starch,soluble total sugar and N,P and K contents of the fourth leave and the contents of endogenous hormones of the fourth node in branch were measured.The results were as follows:(1)The process of 'Sumer black' winter bud morphological differentiation was divided into five periods:Leaf bud period,beginning of differentiation,anlagen development,formation of main axis of the inflorescence primordium,formation of the inflorescence primordium.(2)Summer pruning promoted the flower bud differentiation by shortening the process of flower bud differentiation time and improving the flowering rate of winter buds of'Summer black' grape.In all summer pruning treatment levels,the time of duration from anlagen development to the inflorescence primordium formation were shortened by 15-31 days and the flowering rate increased by 13.3%-46.7%compared with the control.The effects of the three treatment levels on the flower bud differentiation process and flowering rate of different node buds were different.The flowering rate of the buds at 2-3 sections under the pinching node was higher than other buds.Among the summer pruning treatment levels,they had the same effect to promote flower bud differentiation that pinched at the 4h and 6th nodes above the anthotaxy on the 4th,6th,7th node bud.pinched at the 4th nodes above the anthotaxy was better than others on 4th node bud,pinched at the 6th nodes above the anthotaxy was better than others on 8th and 9th node bud.(3)For the treatments of three growth regulators 6-BA,CCC and ETH,spraying different concentrations of 6-BA could shorten the process of flower bud differentiation especially for the 6th and 7th node buds,in which the time duration of the process of flower bud differentiation were shortened by 8-23 days and the flowering rate were increased by 6.7%-20%comparing with the control.Spraying CCC treatment showed the same tendency but the effect was not as good as 6-BA.Spraying ETH can shorten the process of flower bud differentiation,but the flowering rate was no significant effect.(4)Among the treatments,summer pruning and 6-BA spraying showed better effect on the flower bud differentiation than others.In both treatments,during the period from beginning of differentiation to the inflorescence primordium formation,the contents of IAA,GA3,Z and CTK in branch and the contents of soluble sugar and starch in leaves were significantly higher than those of the control,the N level and P was lower,but K levels were higher than the control before anlagen development peak period. |
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