优质、抗热同源四倍体不结球白菜的创制及鉴定

以二倍体抗热不结球白菜品种‘依伶’为材料，用不同浓度秋水仙素溶液处理子叶期生长点，对变异株进行倍性鉴定，研究不同倍性水平的营养品质、农艺学性状以及抗热性。结果表明：（1）0.2％秋水仙素处理4次的效果最好，四倍体加倍率为7.64％。与二倍体相比，叶片长和宽、叶柄长和宽、花器官、气孔、花粉粒、叶重、柄重、开展度、单株重均增加或增大，但结实率明显降低，以上指标差异均达显著或极显著水平。流式细胞仪及染色体鉴定四倍体DNA含量、染色体数目均为二倍体的2倍。小区产量比二倍体高出12.62％；（2）四倍体叶片和叶柄中可溶性总糖、可溶性蛋白、干物质分别增加了7.32％、74.85％，3.91％、17.22％，1.94％、4.89％，有机酸降低了22.56％、25.00％，差异显著；（3）热胁迫下，二、四倍体不结球白菜叶片的MDA、游离脯氨酸、可溶性蛋白含量均增加，恢复期内含量都降低，但二倍体MDA、游离脯氨酸含量一直高于四倍体，可溶性蛋白低于四倍体。四倍体表现出优质、抗热的特点。

Induction and Identification for Autotetraploid Non-heading Chinese Cabbage in High-quality and Heat-tolerance

Using diploid non-heading Chinese cabbage ‘Yi-ling’ ,the apical portion of their seedlings were treated with colchicine solution in different concentration .The variant plants were selected and identified in their ploidy , and were also studied in their characters of morphology ,anatomy ,cytology ,their heat-tolerance ,agronomic and nutritional traits . The results indicated that the treatment in colchicine 0.2 mol ·L ^-1 for 4 times resulted of tetraploid doubling in 7.64% .Comparing with the diploid plant ,the tetraploid plants were significantly increased in the length and width of leaf and petioles ,the number of flowering organs ,stomata and pollen ,the weight of leaf , petioles and plant ,while setting percentage was receded remarkably .Based on the diploid plants ,the contents of total soluble sugar ,soluble protein and dry matter in autotetraploid plants were increased by 7.32% ,74.85% and 3.91% for the leaves , and by 17.22% , 1.94% and 4.89% for the petioles , respectively . Similarly in the comparison ,the content of organic acids in autotetraploid plant leaves and petioles was decreased significantly by 22.56% and 25.00% , respectively . Under 42℃ heating stress , the content of MDA and free proline were significantly lower while soluble protein was higher in autotetraploid plants than in diploid plants . The results indicated that autotetraploid plants performed in high-quality and heat-tolerance .