矮紧型、抗病同源四倍体不结球白菜矮桩秋冠新材料创制

为创制矮紧型、抗病同源四倍体不结球白菜矮桩秘冠新材料,使用浓度为0.2%的秋水仙素处理二倍体不结球白菜矮桩秋冠植株子叶期生长点,通过形态学、解剖学、细胞学特征和使用流式细胞仪进行鉴定,筛选出同源四倍体植株,并进行农艺性状、营养指标、光合能力和抗病性测定。形态学鉴定结果显示,四倍体植株的种子、花器官、荚果表现出巨大化,但整体株型和叶片变小。解剖学鉴定结果发现,四倍体植株气孔变大但单位面积密度减小,花粉粒变大且形状不规则。细胞学鉴定中,二倍体植株细胞染色体数为20条,四倍体为40条,是二倍体的2倍。流式细胞仪鉴定结果表明,二倍体细胞核DNA相对含量峰值在50处,四倍体细胞核DNA相对含量峰值在100处,与细胞学鉴定结果一致。农艺性状中,四倍体植株的单叶质量、十叶厚有所增加,但叶柄长、株高、叶长等有一定程度的降低。营养品质中,四倍体可溶性糖、纤维素、叶绿素含量减少,氨基酸、有机酸含量增加。光合特性分析结果发现,与二倍体相比,四倍体的最大净光合速率、表观量子效率、暗呼吸速率分别增加了29.192%、16.071%和14.0947,光饱和点降低,说明四倍体植株比二倍体具有更强的光合效率。抗病测定结果发现,四倍体植株叶片对灰霉病的抗性明显增强。经选育获得了矮紧型、抗病不结球白菜同源四倍体矮桩秋冠新材料,为不结球白菜种质创新和新品种培育奠定了基础。

Induction and Identification of Autotetraploid of Non-heading Chinese Cabbage Aizhuangqiuguan and Analysis of Its Quality

The growth points of cotyledon stage of a diploid Chinese cabbage cultivar aizhuangqiuguan were treated with 0.2% (W/V) colchicine. Then, the autotetraploid plants were identified and screened by morphology, anatomy, cytology, flow cytometry, and the agronomic traits. The nutritional indexes, photosynthetic capacity and disease resistance were measured simultaneously. Results show that in morphology, the seeds, flower organs and pod of tetraploid plants were giant, but the whole plant row and leaf were smaller than that of diploid plants. In anatomy, the stomata of tetraploid plants became larger, but the density per unit area decreased, and the pollen grains became larger and irregular. In cytology, the number of chromosomes in diploid cells was 20, while in tetraploid was 40, which is the double of that of diploid. The peak value of nuclear DNA in diploid cells was 50 and that in tetraploid cells was 100, consistent with cytology identification results. In agronomic traits, the quality of tetraploid plants signal leaf, thickness of ten leaves increased, but the length of petiole, plant height, and the length of leaf reduced to a certain degree. In nutritional quality, the contents of soluble, cellulose and chlorophyll in tetraploid decreased, while the contents of amino acid and organic acid increased in tetraploids. In photosynthetic characteristics analysis, the maximum net photosynthetic rate, apparent quantum efficiency and dark respiration rate of tetraploid plants were significantly increased compared with that of diploid plants, but the light saturation point decreased, indicating that tetraploid plants had stronger photosynthetic capacity than diploid plants. Meanwhile, the resistance of tetraploid plants to Botrytis cinerea was significantly enhanced. Finally, a new material of aizhuangqiuguan' was obtained, which laid a foundation for germplasm innovation and new variety cultivation of non-heading Chinese cabbage.