| Blueberry (Vaccinium ssp.) is one of the Ericaceae Vaccinium plants. As a new fruit tree, itpossesses the health function for promoting clear vision, anti-cancer, anti-aging, preventing alzheimer’sdisease and cerebrovascular disease. Recent years, it develops very fast in many countries as one of theexcellent fruit trees, especially in Europe and the United States. British authority nutritionists considerblueberry as the first of the15kinds of healthy foods, and Food and Agriculture Organization of theUnited Nations (UNFAO) consider it as one of the five human health foods. Flowering is the importantperiod in the process of plant development, and is the important turning point from vegetative stage toreproductive stage. Blueberry is one of the trees which flower the easiest. And flowering determines theyield for the year directly. Therefore, it is necessary to study the flowering mechanism of blueberry nomatter from flowering theory to solve practical problem. In this paper, we research the morphogenesisof flower development in blueberry by paraffin wax production technology, discuss the hormonechanges in the blueberry flowering process by enzyme-linked immunosorbent assay (ELISA)technology, clone homologous gene LFY from blueberry by the method of PCR, and analyze thetemporal and spactial change of LFY expression by real-time quantitative PCR technique. The floweringmechanism of blueberry was discussed from the point of morphological anatomy, physiology andmolecular biology. The main results were:（1）The flowering period of blueberry "O’neal" was from March1to April2, which lasted32days. The flowering period of blueberry "Tifblue" was from March15to April18, which lasted34days.The flowering period of blueberry "Gardenblue " was from March20to April18, which lasted29days.（2）The morphological differentiation of flower bud in blueberry was divided into six stages,including start differentiation stage, inflorescence primordium differentiation stage, sepal primordiumdifferentiation stage, corolla primordium differentiation stage, stamen primordium differentiation stageand carpels primordium differentiation stage respectively. Among them, the carpel differentiation stagecan be divided into the early, mid and later stage of the carpel differentiation. The morphologicaldifferentiation of flower bud in blueberry "O’neal" started from August24to the end of October18,which lasted54days. The morphological differentiation of flower bud in blueberry "Tifblue" startedform September9to the end of October23, which lasted44days. The morphological differentiation offlower bud in blueberry "Gardenblue " started from September9to the end of October18, which lasted39days.（3）The high level of zeatin riboside (ZR) content was needed during the stages of flower budphysiological differentiation and dormant, and the low level of ZR can promote flower organ formationand flower bud germination in blueberry. The low levels of GA had a promoting effect for physiologicaldifferentiation, transformation from morphological differentiation stage to dormant stage, and flowerbud germination in blueberry. The high level of GA had a promoting effect for the mid-late formation of floral organ and the formation of the inflorescence axis at dormant stage. The high level of IAA had apromoting effect for physiological differentiation stage, mid-late formation of floral organ, flower budgermination and the inflorescence axis at dormant stage in blueberry. The low level of IAA had apromoting effect for the early stage of morphological differentiation, the early formation stage of flowerorgan and transformation from morphological differentiation stage to dormant stage in blueberry. Thelow level of ABA can promote germination of flower bud in buleberry. And the varieties with the lowcontent of ABA can bloom more easily.（4）The fragment of LFY gene was cloned using the specific and degenerate primers according tothe known conservative sequence of LFY genes in Ericaceae plants, and the length is1141bp. The3’end sequence of LFY gene was cloned according to the obtained LFY gene fragment by3’RACEamplification technology, and its length is827bp. The splicing length is1660bp.（5）The expression of StLFY gene was different in the different positions of blueberry. Thehighest expression of StLFY was noticed in the flower bud, followed by leaf, and slightly expression inthe stem, and lowest expression was in the roots and flowers. The formation period of flower bud inblueberry was different in different varieties "O’neal","Tifblue" and "Gardenblue", which was July24,July14and August24, respectively. StLFY gene can promote flower organ formation in blueberry,especially in the mid-late period. Low expression of StLFY gene was propitious to the transformationfrom morphological differentiation stage to dormant stage in blueberry. StLFY gene plays a key role ofpromoting flower bud germination in blueberry. |
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