High-Frequency Regeneration of the Drought-Tolerant Tree Melia volkensii Gurke Using Low-Cost Agrochemical Thidiazuron

Abstract

Melia volkensii Gurke is a drought-tolerant tree native to East Africa's arid and semiarid lands (ASALs), with vast but underutilized potential for agroforestry and sustainable livelihoods in the ASALs. Its cultivation is limited by difficulties in propagation via conventional means. Full exploitation of the ability of thidiazuron (TDZ) to elicit regeneration in plant tissue cultures, as sole plant growth regulator (PGR), is hampered by high costs. This study tested the effectiveness of a low-cost agrochemical TDZ for in vitro propagation of M. volkensii. Zygotic embryos from mature seeds were cultured on Gamborg's B5 medium containing 0 to 4 mg/L of agrochemical TDZ from Kingtai Chemicals Co.,Ltd., China. Callus induction frequency was 96.67 to 100%. Significantly large callus fresh mass was produced at 0.05 mg/L TDZ concentration (ANOVA, P < 0.001). The effect of TDZ on embryogenicity was significant over certain ranges of concentrations (Anova, P < 0.001). Multiple somatic embryos developed within 14 days of subculture to hormone-free B5 medium. Somatic embryos developed into microshoots which elongated when transferred to 1/2 MS medium supplemented with 0.1 mg/L 6-benzylaminopurine plus 10% coconut water. The Kingtai-TDZ showed a high potency and suitability for use in M. volkensii tissue culture.

Combating Desertification through Enhancement of Woody Floral Diversity in the Drylands of Kenya: Analysis, Milestones, and Strategies

“…Full exploitation of the ability of thidiazuron to elicit regeneration in plant-tissue cultures, as a sole plant growth regulator, was found to be hampered by high costs. Alternative effective and low-cost agrochemical thidiazuron for in vitro propagation of M. volkensii was found to be Kingtai-TDZ, which has a high potency and suitability for use in tissue culture of the species [61]. Because of difficulties in seed germination, land users sometimes go for the use of plants produced from root and stem cuttings, rather than from seedlings, and researchers have focused on the possibility that root and stem cuttings may be used for propagation, rather than seedlings [62].…”

“…However, this species is heavily exploited in its natural stands and the trend has been worsening over the last decade owing to shortage of alternative hardwood species in drylands. As a result, programs promoting domestication of the species as a plantation species are ongoing [60][61][62].…”

Thidiazuron: New Trends and Future Perspectives to Fight Xylella fastidiosa in Olive Trees

“…TDZ ( N -phenyl- N ′-1,2,3-thiadiazol-5-ylurea) is a substituted diphenylurea compound [ 46 ]. Belonging to the diarylurea class, it may be easily synthesized [ 47 , 48 ], and is also characterized by a low-cost [ 49 ]. It was first reported to have cytokinin activity in 1982 [ 50 ] and since then, TDZ has been used as a growth regulator for abscission of green-turgid leaves of cotton to facilitate the picking of bolls [ 2 ].…”

Variation of Morphological Traits and Quality Indices of Micropropagated Melia volkensii Gürke Clones before Field Planting

“…Plant tissue culture has the potential to significantly increase the supply of planting material in terms of quality and quantity. Despite previous work on M. volkensii in vitro propagation [14,15], information on the morphological variation between micropropagated clones after acclimatization is still scarce. In recent years, our research team has refined the rooting and acclimatization protocols for M. volkensii clones [11].…”