体细胞突变体筛选法获得象草耐盐植株

Acquirement of Salt-tolerant Plants by Somatic Mutant Screening in Pennisetum purpureum

以象草幼穗离体培养诱导产生的胚性愈伤组织为外植体,在愈伤组织继代培养基中添加10～20 g/LNaCl,离体筛选得到的白色颗粒状愈伤组织在分化培养基上再生出植株。再生植株耐盐性鉴定结果:6 g/L海盐的1/2 Hoagland营养液每隔7 d浇灌1次,共浇灌4次,处理24 d时,对照植株全部致死;处理42 d时,24 g/L NaCl离体筛选获得的MN12-1和MN12-2体细胞再生植株生长良好。取MN12-1、MN12-2植株和对照株的节间嫩芽组培苗进行耐盐盆栽鉴定:4 g/L、6 g/L海盐的1/2 Hoagland营养液每隔7 d浇灌1次,共浇灌3次,生长28 d时,MN12-1和MN12-2植株的叶、茎、根干重显著高于对照植株,MN12-2植株各部分的干重比对照植株提高100%以上,差异极显著。SRAP检测结果表明,MN12-1、MN12-2植株与对照植株在分子水平上存在差异,确认获得了耐盐体细胞突变体。

The embryogenic calli from immature inflorescences of Pennisetum purpureum were used as the recipi- ent, and white pellet calli were selected in callus subculture medium supplemented with 10-20 g/L NaCl. In the differenti- ation medium, plantlets were obtained from pellet calli with sah-toleranee. Evaluation of salt tolerance of regenerated plants showed that all plants of CKs were dead after watered by 6 g/L sea salt in 1/2 Hoagland for a 24 d treatment. The plants of MN12-1 and MN12-2 grew well after 42 d treatment. The plants from young bud of MN12-1 and MN12-2 and CK by tissue culture, were evaluated for the salt tolerance. Compared with CK, dry matter in the leaves, stems and roots of MN12-1 and MN12-2 plants was significantly increased（P〈0.05） after watered by 4 g/L sea salt or 6 g/L sea-sah in 1/2 Hoagland for 28 d growth. Dry matter in the leaves , stems and roots of MN12-2 plant was increased even more than 100% in eompari-son with that in CK plants （P〈 0. 01 ）. SRAP analysis confirmed that MN12-1 and MN12-2 plants were different from CK plants in the molecule level, and were considered as somatic salt-tolerant mutants.