栓皮栎体胚的增殖、成熟和萌发

以栓皮栎实生苗叶片为外植体诱导体细胞胚胎发生,调查碳水化合物、渗透剂和植物生长调节剂对体胚增殖、成熟和萌发的影响,建立体胚增殖、成熟和萌发的培养基方案.叶片外植体在附加1.0 mg·L-1NAA和0.5mg·L-1BA的起始培养基上诱导形成前胚性团块.这些胚性团块在增殖培养基上培养6周,在附加1 mg·L-1BA、0.25 mg·L-1NAA和3%蔗糖的MS培养基上增殖效果最好.将单个体胚转接到成熟培养基上进行培养,蔗糖浓度对栓皮栎体胚成熟以及后续的萌发有显著影响.成熟培养基中附加5%的蔗糖,体胚成熟率和萌发率分别达到63.5%和33.8%.虽然在成熟培养基中附加ABA有利于体胚成熟,但对体胚的进一步萌发没有促进作用.为了提高萌发率,成熟体胚在附加植物生长调节剂的萌发培养基上进行培养,以及进行预冷处理.成熟体胚4℃冷处理没有促进胚根和上胚轴的发育萌发.在附加0.5 mg·L-1BA和0.25 mg·L-1 IBA的1/2 MS萌发培养基上,体胚萌发率达到65.9%,再生植株转化率达到9.4%.

Proliferation, Maturation and Germination of Somatic Embryos in Quercus variabilis

In the present study, leaf segments from Quercus variabilis seedlings were used as explants to induce somatic embryogenesis. The influence of carbohydrates, osmotic agents, and plant growth regulators (PGRs) on somatic embryo proliferation, maturation and germination was investigated and a protocol was developed. On the initiation medium containing 1.0 mg·L-1 a-naphthaleneacetie acid(NAA) and 0.5 mg·L-1 6-benzylaminopurine(BA) proembryogenie masses(PEMs) were induced from leaf explants. These PEMs were cultivated on a proliferation medium for 6 weeks. The best proliferation was obtained on MS basal medium with 1 mg·L-1 6-benzyladenine(BA), 0.25 mg·L-1 NAA and 3 % sucrose. Individual somatic embryos were then grown on a maturation medium. Sucrose concentrations had significant influence on embryo maturation and germination. With 5% sucrose in the media, 63.5% embryos matured and 33.8% germinated. Although abseisic acid(ABA) was in favor of somatic embryo maturation, it had no positive effect on germination. To promote germination, mature embryos were cultured on the germination medium, and treated with a low temperature. Cold treatment at 4℃ was ineffective in stimulating epicotyl and radicle formation. The rate of embryo germination reached 65.9% on the germination medium consisted of 1/2 MS basal medium with 0.5 mg·L-1 BA and 0.25 mg·L-1 indolebutyric acid(IBA), and the rate of conversion was 9.4%.