枣疯病病原在树体内的分布和运转规律

Chinese jujube is an important ulti-purpose fruit tree both in China and South Korea. Witches' broom disease is a destructive disease of Chinese jujube caused by phytoplasma (MLO). The distribution of witches' broom-related phytoplasma in Fuping Dazao (an important commercial Chinese jujube cultivar) was studied in a systematic way with fluorescence microscope. The result showed that the distribution of phytoplasma in Chinese jujube tree had some specific properties, such as wide -spread, unwell-distribution and corresponding distribution (under ground and above ground). In different seasons, witches' broom-related phytoplasma concentrated in different parts of the same organ. The property of unwell-distribution could be observed easier in the trees that symptoms were just found. The symptoms of phytoplasma at microscopic and eyeable level were divided into 6 grades respectively. The relationships between the two kinds of classification system were also pointed out. In addition, the method of the water culture buds from diseased branches during winter was used firstly in this paper, the result that a great amount of vital phytoplasma existing in branches during whole winter was verified effectively. So we believed that phytoplasma of JWB had strong ability of naturally living in the aboveground throughout the winter. This standpoint did not support the traditional belief that phytoplasma concentrated in root during winter.

枣疯病是枣树生产上迫切需要研究解决的重大毁灭性传染病害。该项目拟借助枣疯病病原的荧光显微观察和分子标记等现代科技手段和方法，对枣疯病病原的繁殖、分布和运转消长规律及其症状演变的关系等，与枣疯病病树治疗密切相关的基础问题进行深入系统的研究，澄清有关模糊认识。该研究对开展枣疯病病树工作具有重要的指导价值，同时还可为其他植原体病害的防治提供参考。