Studies On Leaf Regeneration And Polyploid Induction Of Rabbiteye Blueberry

Premier, one of the Rabbiteye Blueberry varieties,used as materials, were established leaf regeneration system by tissue culture, then observed the regeneration process by paraffin section, and treated its stem tip with colchicine to obtain polyploids, then identified the plant that was treated, which laid a foundation that benefit for Rabbiteye Blueberry tissue rapid propagation and obtain new varieties.The main results were as follows:1. The high frequency, high efficiency leaf regeneration system of rabbiteye blueberry in vitro culture was established. The results were showed that the most effective method was to use the WPM as the basic culture medium, add1.4～1.7mg/L of ZT into it, then cross-cut leaves into two portions in1/3from the tip of the leaves, and cultured in the dark for20d (25±2℃) before cultured in the15h lighting (20001ux,25±2℃) and9h darkness for each day, its induction rate could reach86.8%.2. The leaf regeneration of premier is the direct organogenesis. The results of histological observations were showed that adventitious bud mostly originated from the vascular bundle of vein. When cultured for3days, the parenchyma cells in the vein of leaves in vitro culture showed the characteristics of a large nuclear and dense cytoplasm; Those cell divided into groups then differentiated into adventitious buds and then developed became plantlets. Regeneration of adventitious buds on leaf explants of blueberry in vitro Culture was out of sync, and the earliest meristem cells formed and breakthrough leaf epidermis after cultured for12days.3. The stem tip, cut from leaf regeneration, was treated with colchicines to obtain polyploidy. When treated with50mg/L of colchicines for50days or60mg/L of colchicines for40days, the effect of induce variation plant was the optimum, reaching a variation rate of more than30%, which was conducive to obtain polyploidy.4. The untreated plants and the variation plants were investigated using the method of wall degradation and hypotonic treatment of making chromosomal preparations. The results were showed that the chromosome number of untreated plants is2n=6x=72, while the induced polyploidy increased obviously, was more than72. The induced polyploidy grew slowly, with short and strong stem, its epidermal hair on leaves and stems increased obviously, stoma was larger.