Study On The Physiological Mechanism Of Flower Bud Differentiation Of Loquat ’Zaozhong6’ Summer Branches

’Zaozhong 6’was Fujian fruit research use famous large fruit loquat’Jiefangzhong’as the female parent, Japanese early maturing variety ’Moriowase’ as the male through sexual hybridization and gains a new early maturity varieties, has the advantages of strong vigor, high yield good performance and strong stress resistance, is China’s current promotion mainly precocious excellent one of loquat cultivars. Flower bud differentiation as a symbol of plants from vegetative growth to reproductive growth, plays an important role in plant life. This experiment was based on the observation of the phenological phase and the morphological observation of the morphogenesis process in the flower bud differentiation of’Zaozhong 6’in Panxi region, Combine with determine the dynamic change of the contents of nutrients, enzyme activities and endogenous hormones in leaves and flower buds during flower bud differentiation, explore the physiological mechanism of flower bud differentiation, expected to provide theoretical basis for high yield cultivation of loquat. The main results are as follows:1.due to the special natural ecological and climatic conditions in panxi region, ’Zaozhong 6’ loquat one year can sprout 4 shoots, respectively for spring shoots, summer shoots, autumn shoots and winter shoot, a year can open flower 3 times, a year fruit ripening 3 times, fruit in the year October to the next year March mature. The summer shoot as the bear fruit of the parent branch, can be appear on the market before Spring Festival, the quality is good, the time series advantage is outstanding, the commodity value is high.2.The critical period of flower bud differentiation of ’Zaozhong 6’ summer shoot was in 6-7 months. At this point the growth point of the protoplast is very unstable, the internal and external factors have a high degree of sensitivity, it’s easy to change the direction of metabolism. It’s a critical period for controlling the differentiation of flower buds. Terminal bud in different conditions can be differentiated into leaves or blossom buds.3.’Zaozhong 6’ in panxi region summer shoot bud differentiation can be divided into the following periods:Undifferentiated stage、Stage of inflorescence axis primordia differentiation、Stage of inflorescence axis primordia differentiation、Stage of sepal differentiation、Stage of petal primordia differentiation、Stage of stamen differentiation、 Stage of pistil differentiation. Begin flower bud differentiation in late June to early September flowering only need three months. The progress of differentiation is different for flower buds of different locations of the same plant and different single flowers in the same inflorescence.4.Soluble sugar, reducing sugar, starch and protein content in the leaves and blossom buds of the different stages of the ’Zaozhong 6’ during the flower bud differentiation has a trend of rise and fall. In general the nutrient content in leaves was higher than that of blossom bud, leaf with strong nutrient supply capacity have a positive effect on flower bud differentiation.5.The changes of PPO, POD and PAL activity in the leaves and blossom buds during the flower bud differentiation of the ’Zaozhong 6’ were diauxie curve. PPO, POD and PAL in blossom buds were higher than that of leaves, higher activity of PPO, POD and PAL are favorable to flower bud differentiation.6.In the process of flower bud differentiation of ’Zaozhong 6’, The higher content of ABA and ZT in the leaves and blossom buds played an important role in promoting the differentiation of loquat flower buds, The high content of GA3 and IAA is inhibited the flower bud differentiation of’Zaozhong 6’, a lower content of GA3 and IAA was beneficial to the initiation of flower bud differentiation. The process of flower bud differentiation in loquat should be the result of the conjunct effects of many hormones. ZT/ABA was not obvious in the stage of flower bud differentiation, Other high ratios of ZT/IAA, ZT/GA3, ABA/GA3 and ABA/IAA were in favor of loquat flower bud differentiation.7.The flower bud differentiation of loquat’zaozhong6’is a complex morphological process.The accumulation of nutrients in the process of nutrition growth is very important for them, and the adequacy of the nutrient substance determines the quality of flower buds.Therefore, in the actual production should pay attention to deal the relationship between growth and development, and timely to take appropriate cultivation management measures to regulation the flower bud differentiation, in order to get more income.