珍稀观赏竹白纹椎谷笹的组培快繁与叶色变异

Tissue culture and leaf color variation of rare ornamental bamboo Sasaella glabra f.albostriata

白纹椎谷笹(Sasaella glabra f.albostriata)是一种引自日本的珍稀地被观赏竹,为了建立其高效快繁体系,以当年生幼嫩带芽茎段为外植体,对芽增殖培养基、生根培养基及继代培养时间进行筛选。在组培苗移栽1年后进行埋鞭繁殖,研究组培竹苗的繁育能力。结果表明:最佳芽增殖培养基为MS+4.0 mg·L^(-1)6-BA+0.001 mg·L^(-1)TDZ,培养30 d时,增殖系数为6.5;最佳生根培养基为MS+0.3 mg·L^(-1)IBA或0.3 mg·L^(-1)NAA,生根率可达100%,根系良好,移栽后成活率100%。来源组培苗的微型鞭段埋鞭繁殖1年后,出笋系数为相同规格容器苗微型鞭段的4.21倍。组培苗在移栽第2年出现叶色分离现象,由原来的白绿相间的单一颜色,转变为少量全绿叶、全白叶、白叶绿条纹、绿叶白条纹4种类型的叶片。叶片的光合色素含量均随着叶片绿色条纹加宽而显著增加,但是叶绿素a/b却无显著差异。选取了15个叶色变异相关基因进行了半定量RT-PCR分析,发现psaA、psbB、psbC和psbD基因在叶片的白色组织中转录水平明显低于绿色组织。

In this study,buds from the current year young stems were used as explants to establish an efficient micropropagation system of Sasaella glabra f.albostriata from Japan including the optimal bud proliferation medium,rooting medium and subculture time.One year after transplanting,the micro-rhizome of banboo seedlings were used for propagation to study the breeding ability of tissue cultured bamboo seedlings.The optimal bud proliferation medium was MS+4.0 mg·L^(-1)6-BA+0.001 mg·L^(-1) TDZ,and the proliferation coefficient was 6.5 when culturing for 30 days.The optimal rooting medium was MS+0.3 mg·L^(-1) IBA or 0.3 mg·L^(-1) NAA,the roots were strong and the rooting rate was 100%.The survival rate of transplanting was 100%.After planting for one year,the shoot propagation coefficient by the micro-rhizome from tissue cultured seedlings was 4.21 times that of the micro-rhizome from container seedlings with the same size.Leaf color separation of tissue culture seedlings appeared in the second year of transplanting,which changed from the original single color of white-green stripe leaves to a few green leaves,white leaves,white leaves with green stripes,and green leaves with white stripes.The photosynthetic pigment contents of leaves increased significantly with the widening of green stripes,but chlorophyll A/B had no significant difference.A total of 15 genes related to leaf color variation were selected for semi-quantitative RT-PCR analysis,and it was found that the transcription levels of psaA,psbB,psbC and psbD genes in white tissue were significantly lower than those in green tissue.