人工合成冬性六倍体小麦的研究

Development of Winter Synthetic Hexaploid Wheat

以冬性四倍体硬粒小麦(Triticum durum,2n=28,AABB)为母本与粗山羊草(Aegilops tauschii,2n=14,DD)杂交,得到的单倍体幼胚(n=21,ABD)经组织培养拯救,获得的幼苗经染色体加倍而成为合成小麦(AABBDD)。从中鉴定、筛选出冬性的合成小麦。幼胚仅在1/2 MS培养基上培养,成苗率为75.81%;根据幼胚的发育状态,将发育较完善的幼胚直接接种在1/2 MS培养基上,将发育不良的幼胚先接种于1/2 MS+2 mg/L 2,4-D培养基上进一步养育幼胚,之后视幼胚发育状况再将其转入1/2 MS培养基中培养成苗,此方法的成苗率为92.44%,较前者的成苗率提高了16.63%。染色体加倍在冬季塑膜拱棚内用0.05%秋水仙素进行半根法处理,较容易获得健壮苗,并且分蘖多。

Immature haploid embryos（ n = 21,ABD） were obtained by crossing durum wheat（ Triticum durum,2n = 28,AABB） as the female parent and Aegilops tauschii（ 2n = 14,DD） as the male parent. The haploid embryos were rescued by tissue culture. The plantlets regenerated were treated with colchicine to double their chromosomes and the synthetic wheat with winter growth habit was produced. The regeneration percentage of haploid plantlets was only 75. 81% using 1 /2 MS medium,but 92. 44% haploid plantlets were obtained when the immature embryos were cultured on 1 /2 MS medium and 1 /2 MS medium supplemented with 2 mg / L 2,4-D alternately. The medium alternation was based on the development of immature embryos. If immature embryo developed well,1 /2 MS medium would be used; otherwise 1 /2 MS medium containing 2 mg / L 2,4-D would be used. The poorly developed immature embryos grew well on the medium containing 2 mg / L 2,4-D,and then they were moved to 1 /2 MS medium to produce more plantlets. Double haploid plantlets（ AABBDD） were gained by using 0. 05% colchicine with method of half-root in greenhouse in winter.