优质同源四倍体菜心新材料的创制及特性分析

Creation and Characterization of New Materials for High Quality Autotetraploid Chinese Flowering Cabbage

为获得优质的菜心同源四倍体新材料,本研究采用0.2%(W/V)的秋水仙素溶液点滴二倍体菜心LCX017幼苗子叶生长点,通过形态学、解剖学、细胞学以及流式细胞仪等方式鉴定到诱导成功的同源四倍体植株,并对二、四倍体的农艺性状、营养品质、光合特性等方面进行分析比较。结果表明,形态学与农艺性状方面,四倍体植株在叶片、花器官、种荚等方面表现出“巨大性”,叶宽、叶厚增大,菜薹直径变粗,重量增大;解剖学方面,四倍体叶片气孔相对二倍体更大,气孔密度降低;花粉粒相比二倍体变大且呈现棒状或橄榄状;细胞学方面,四倍体植株的根尖染色体数目是二倍体的2倍;流式细胞仪鉴定结果显示,四倍体的DNA荧光强度是二倍体的2倍;营养品质方面,相较于二倍体,四倍体植株中可溶性糖、纤维素、有机酸以及叶绿素含量显著上升,硝态氮含量下降22.92%,可溶性蛋白含量无显著变化;此外,结合光响应曲线分析发现,四倍体在强光和弱光条件下的适应能力均强于二倍体。综上,本研究成功诱导出了优质的同源四倍体菜心新材料,丰富了不结球白菜的种质资源。

In order to obtain high-quality autotetraploid new materials of Chinese flowering cabbage,the cotyledon growth points of diploid Chinese flowering cabbage LCX017 seedlings were spotted with 0.2%(W/V)colchicine solution in this study.The autotetraploid plants were identified by morphological,anatomical,cytological and flow cytometry,and the agronomic traits,nutritional quality,photosynthetic characteristics and other aspects were analyzed and compared between diploid and tetraploid.The results showed that in terms of morphological and agronomic traits,tetraploid plants showed‘giganticity’in leaves,flower organs and seed pods,the leaf width and leaf thickness increased,the bolt diameter became thicker and the weight increased.Anatomically,the stomata of tetraploid leaves were larger and stomatal density was lower.The pollen grains of tetraploid were larger than diploid and showed rod-shaped or olive-shaped.In terms of cytological,the number of chromosomes in the root tips of tetraploid plants was twice that of diploids.Flow cytometry identification showed that the DNA fluorescence intensity of tetraploid was twice that of diploid.In terms of nutritional quality,the content of soluble sugar,cellulose,organic acid and chlorophyll in tetraploid plants increased significantly,the nitrate nitrogen content decreased by 22.92%,and the soluble protein content did not change significantly.In addition,the light response curve analysis showed that tetraploid had better adaptability than diploid under strong and weak light conditions.Therefore,a new material of highquality autotetraploid Chinese flowering cabbage was successfully induced in this study,which enriched the germplasm resources of non-heading Chinese cabbage.