Effect of two propagation systems on flower bud differentiation and development of strawberry fruit

【Objective】This study aimed to find the effect of different nursery production method on flow-er bud differentiation and development of strawberry and the physiological mechanism of flower bud differ-entiation for early ripening cultivation.【Methods】The cultivar‘Benihoppe'(Fragaria ananassa Duch.)was used as experimental material to compare the traditional tunnel model(CK)with the horizontal shelfwith matrix-plugs(NEW). Both the models were under the condition of rainproof. The contents of C,Nand the endogenous hormone(GA,IAA,ABA and CTK)were measured during the flower bud differenti-ation and fruit development. Fresh and dry fruit weight,plant height and crown diameter,phonologicalphase,fruit quality and yield were also investigated at different stages.【Results】The timing of flower buddifferentiation in NEW treatment was on 9 August to 19 August which was earlier,while CK had no flowerbud differentiation before 24 August. CK had a high content of C,N than NEW,and CK had a stabletrend of C/N ratio while NEW had a uprising trend from 9 August to 19 August. CK had a significant high-er content of GA and IAA than NEW. ABA content of NEW increased in the beginning,,then droppeddown after 19 August,while CTK kept a uprising trend during the whole process,but CTK content ofNEW was lower than that of CK. Hormones ratio was also closely related to the flower bud differentiationof strawberry,the ratio of ABA/GA was higher than CTK/GA,so did ABA/IAA to CTK/IAA. The trends ofABA/IAA showed firstly increasing,then decreasing and eventually stable,and the maximal value was up to 0.73. Every plant morphological index of CK was higher than that of NEW,but the budding date,full flowering date,beginning harvesting date of NEW was 37 d,39 d,44 d earlier than that of CK,re-spectively. There was no significant difference in the firmness and soluble solids content of the fruit be-tween CK and NEW. The average single fruit weight of CK was bigger than NEW. NEW exhibited the sig-nificantly early ripening(early yield took 48.2% of the total),but the total production of two treatmentswas equal.【Conclusion】NEW could promote the flower bud differentiation and was an effective method forearly ripening cultivation of strawberry. Proper C/N ratio could promote the flower differentiation processwith the C/N theory. ABA may play a dominant role in the flower bud differentiation of strawberry follow-ing by IAA,and relative high ABA/IAA ratio(0.61-0.73)could promote flower bud differentiation as well.