论文部分内容阅读
通过栽培甜菜与白花甜菜杂交,获得了真实杂种VC88-1(VVCC,2n=36)。用栽培甜菜对其回交,合成了异源三倍体甜菜(VVC,2n=27),它具有无融合生殖特性。异源三倍体甜菜具有两个物种的形态特征,表现为中间型,更偏向野生种。植株繁茂,叶片平展深绿色,根形不整有岔根,木质化较强。细胞学检查有丝分裂中期可清晰判定两个物种的染色体,构成独特的9长18短核型。经过几年观察选育已经选育出传递率在80%以上的无融合生殖系9个,并判定为兼性无融合生殖。利用石蜡切片研究了无融合生殖的发生过程,观察到卵细胞等8核胚囊及胚胎发育全过程,认定异源三倍体甜菜胚囊发育为蝶须型,是属于有丝分裂型的二倍体孢子生殖的无融合生殖类型。讨论了异源三倍体甜菜进一步利用的可能性。
The true hybrid VC88-1 (VVCC, 2n = 36) was obtained by crossing the cultivated beet with the white beet. Heterotron triploid beets (VVC, 2n = 27) were synthesized from the cultivated sugar beet by backcrossing and have apomixis reproductive properties. Heterotronomy beet has the morphological characteristics of two species, showing the intermediate type, more biased toward wild species. Lush vegetation, the leaves are flat dark green, root irregularity branches, strong lignification. Cytological examination of mitotic metaphase can clearly determine the chromosomes of two species, constitute a unique 9 long 18 short karyotype. After several years of observation and selection, 9 apomictic germ lines with transmissibility of more than 80% have been selected and found to be facultative apomixis. Paraffin sections were used to study the process of apomixis. The observation of the 8-cell embryo sac of egg cells and the whole process of embryo development indicated that the development of allotetraploid embryo sacs was a mustache, which belonged to the mitotic diploid spore Reproductive apomixis genus. The possibility of further utilization of allotriploid beet was discussed.