甘薯耐旱突变体的离体筛选与鉴定

In Vitro Selection and Identification of Drought-tolerant Mutants of Sweet Potato

以甘薯品种栗子香为材料 ,用PEG6 0 0 0作为耐旱性突变体离体筛选的选择剂 ,将栗子香胚性悬浮细胞培养在含有 0～ 35 % (w/v)PEG6 0 0 0和 2 .0mg·L-12 ,4 D的液体MS培养基中。结果表明 ,甘薯耐旱性离体筛选的适宜选择压为 30 %PEG6 0 0 0。采用多步选择法 ,在含有 30 %PEG6 0 0 0和 2 .0mg·L-12 ,4 D的液体MS培养基中对经 80Gyγ射线辐照的栗子香胚性悬浮细胞进行离体筛选 ,获得了 2 0个耐旱性小细胞团。将这些小细胞团转移到添加2 .0mg·L-12 ,4 D的固体MS培养基上 ,获得了耐旱胚性愈伤组织 ,并形成体细胞胚。将具有体细胞胚的胚性愈伤组织进一步转移到添加 1.0mg·L-1ABA的MS培养基上 ,体细胞胚发芽形成完整植株 ,共获得 18株再生植株。将获得的 18株再生植株移栽到温室 ,获得 11个株系。用苗期干旱处理、叶片保水力及耐旱系数等指标对这 11个株系进行耐旱性分析 ,其中 3个株系的耐旱性显著高于对照。

In vitro selection of drought-tolerant mutants of sweetpotato cv. Lizixiang was studied by using PEG 6000 as selective agent. Embryogenic suspension cultures were cultured in MS medium containing 0～35% PEG 6000 and 2.0 mg·L -1 2,4-D. The results indicated that 30% of the PEG 6000 can be used for the optimal selective agent of drought-tolerance. Embryogenic suspension cultures irradiated with 80 Gy gamma-ray were cultured in MS medium containing 30% of PEG6000 and 2.0 mg·L -1 2,4-D and 20 drought-tolerant cell aggregates were obtained. These cell aggregates were transferred to solid MS medium supplemented with 2.0 mg·L -1 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos were further transferred to MS medium supplemented with 1.0 mg·L -1 ABA, and resulted in the germination of somatic embryos. In this study a total of 18 regenerated plants were obtained. The regenerated plants were transplanted in a greenhouse and 11 lines were formed. Analysis on drought treatment of seedlings, water retaining capacity of leaves and drought coefficient showed that 3 lines had significant drought-tolerance in comparison with the control plants.