外源DNA导入创造抗枯萎病西瓜种质资源

Resistance to Wilt Disease Watermelon Germplasm Resources by Exogenous DNA Introduction

采用DNA浸胚法将供体瓠瓜的总DNA导入西瓜,D1代获得一变异株,变异率为032%.D2代变异植株成株期功能叶过氧化物酶同工酶酶带数增加,出现了供体植株的酶带.变异株部分染色体的臂长、臂比、带型与受体相比产生了明显的变异.果实有22.7%的皮色由深绿变成白色或白皮绿网纹,接近供体瓠瓜的皮色;果实形状有31.0%发生变异;种子的形状和色泽有333%发生变异.初步认为西瓜的性状变异是供体瓠瓜DNA导入的结果.D3代在病圃中筛选出的D31,D32,D33,D34和D35材料,D4代性状已稳定,并且在病圃中表现出对枯萎病的抗性强.苗期接种鉴定结果表明,D31和D32高抗枯萎病,D33和D34中抗枯萎病,D35轻抗枯萎病.

Through the method of soaking embryo,total DNA of donor bottle gourd was extracted and introduced into watermelon .One variant plant in D 1 offspring with variant ratio of 0.32% was obtained.The band number of peroxidase isozyme in functional leaves of D 2 variant plants increased,and some bands of donor's appeared in variant plants.There were obvious variations in some chromosomes' arm length,arm ratio as well as banding patterns between variant plants and recipient. 22.7% of fruit carpodermis color of D 2 plants changed from dark greento white or white color with green net pattern,which was similar to that of the donor.Variations in the fruit shape was observed in 31.0% of D 2 plants and variations in the seed shape and color were observed in 33.3% of D 2 plants.It suggested that variation in the characters of watermelon be induced by exogenous bottle gourd DNA introduction.The characters of D 4 offspring plants of D 3 1,D 3 2,D 3 3,D 3 4 and D 3 5 variant materials which were selected from D 3 offspring plants cultured in contaminated soil were steady already,and disease resistance showed strong when cultured in contaminated soil.Tested by inoculation of the pathogen to young seedlings,D 3 1 and D 3 2 showed high resistance to wilt disease,while D 3 3 and D 3 4 were middle resistant to the disease.