苹果试管染色体组工程育种

Genome engineering breeding of apple in vitro

用秋水仙０．４％和０．８％的浓度，诱变苹果７个二倍体品种自然授粉的胚，通过试管培养，抑制胚芽成梢，促使染色体组突变的四倍体细胞分化不定芽，形成植株。经染色计数和梢端切片，鉴定出一批同质的四倍体株系，部分植株已栽植于果园。此项研究找出了简易可靠的诱变技校，有效地避免或减轻了常规诱变中嵌合体的干扰，为人工创造四倍体种质，有计划地进行多倍体育种开辟了新途径。

Open-pollinated embryos of 7 diploid apple cultivars were treated with 0. 4% and 0.8% colchicine for 24 or 48 h to induce elite mutants. A lot of plantlets were formed from the embyos cultured in vitro after artificially restraining plumules to grow into shoots thus forcing the genome mutated tetraploid cells to differentiate adventitious buds. By means of chromosome counts and section of paraffin-embedded shoot apices,some of the plantlets have been identified as solid tetraploid lines and transferred to an orchard to grow. Experiments revealed that treatment with colchicine at 0. 4% for 24 h forced 36-90% adventitious shoots to be initiated without any phytotoxicity, but that at 0.8% for the same time resultited in much less adventitious shoots and caused phytotoxicity. This study provides an easy and reliable method for inducing mutation and for artificially creating tetraploid germplasm, and may effectively eliminate the disturbance of chimeras resulting from the common-used methods for inducing mutation.'