多头切花菊节间横切薄层不定芽再生的研究

利用节间横切薄层（transverse thin cell layers,tTCLs）培养技术建立不定芽再生体系,可以极大提高植物组织培养的再生频率,并有效控制不定芽玻璃化的发生率。该研究以4个多头切花菊品种:‘Repluse’、‘Regan Elite Improved’、‘Regan Elite Sunny’、‘Regan Elite White’的节间tTCLs为外植体,筛选出不定芽分化所需的最佳生长素种类和浓度、最佳的外植体来源和取材部位,并通过调控琼脂浓度和培养温度来有效降低不定芽玻璃化的发生率。结果表明:试验中的4个品种都能高频再生,不定芽再生率都在70%以上,Ⅰ级节间的tTCLs更易于分化不定芽;不同品种对生长素的种类要求不同,0.1 mg/L的生长素浓度为最适浓度;琼脂浓度过高或过低以及培养温度过高都会增加不定芽玻璃化的发生率。该研究建立了4个品种的高效不定芽再生体系,为菊花的良种繁育以及转基因研究提供了一条有效途径。      

Micropropagation of Cymbidium Sleeping Nymph through protocorm-like bodies production by thin cell layer culture

Transverse thin cell layers (tTCLs) of protocorm-like bodies of two stages of PLBs (30 d and 60 d old) of Cymbidium Sleeping Nymph were used as explants to induce PLBs by using coconut water (CW) as a natural additive. 5% (v/v) CW supplemented to KC medium induced an average of 5 PLBs per responding tTCL of 30 d old PLBs with 83% of responding tTCLs. A low percentage of responding tTCLs were observed in 60 d old PLBs’ tTCLs. Anatomical and confocal microscopic studies traced the origin of PLBs to subepidermal layers of the tTCL. A significantly high percentage of shoot regeneration was obtained from PLBs formed on 1–10% (v/v) CW from tTCLs of 30 d old PLBs in comparison to PLBs induced on control after first subculture on KC medium (without CW). The induced PLBs regenerated into plantlets with velamenous roots and these plantlets were transferred to greenhouse conditions on cocopeat:perlite (9:1) with nearly 100% survival. Post-transfer performance of the plantlets was monitored. The results suggest tTCLs as potential explants (with respect to economy of precious hybrid materials) which can overcome the slow growth of hybrid PLBs and coconut water as a single natural additive for the mass multiplication of commercially important orchids.