Early morphogenesis of kopyor coconut (Cocos nucifera L.) embryos in vitro as affected by light conditions and thidiazuron concentration

S. Susiyanti¹5,*, W.S. Hamidah¹, A.A. Fatmawaty¹, Z. Millah¹, Kartina A.M.¹, M. Mirajiani², S. Abdullah³ and S. Sjaifuddin⁴

¹Department of Agroecotechnology, Faculty of Agriculture, Universitas Sultan Ageng Tirtayasa, Serang, Banten Province, Indonesia
²Department of Agribusiness, Faculty of Agriculture, Universitas Sultan Ageng Tirtayasa, Serang, Banten Province, Indonesia
³Faculty of Plantation and Agrotechnology, Universiti Teknologi MARA, Malaysia
⁴Department of Environmental Studies, Universitas Sultan Ageng Tirtayasa, Serang, Banten Province, Indonesia
5Center of Excellent for Food Security, Universitas Sultan Ageng Tirtayasa, Serang, Banten Province, Indonesia
*Correspondence: susiyanti@untirta.ac.id

Abstract:

Kopyor coconut (Cocos nucifera L.) is a high-value coconut variant characterized by a naturally mutated endosperm; however, its propagation is constrained by low seed viability and inconsistent germination. In vitro culture offers a promising approach for large-scale propagation. This study evaluated the effects of light conditions and thidiazuron (TDZ) concentrations on the early morphogenesis of kopyor coconut embryos cultured in vitro. A split-plot design based on a completely randomized design was applied, with light conditions (dark and continuous light) as the main plot and TDZ concentrations (0, 0.25, 0.50, 0.75, and 1.00 mg L⁻¹) as subplots. The results showed that light conditions did not significantly affect explant height, shoot number and root number, or root length (p > 0.05), although plumule formation occurred exclusively under light conditions. In contrast, TDZ significantly influenced explant height (p < 0.01), while its effects on other parameters were not significant. The application of 0.25 mg L⁻¹ TDZ produced the most favorable response, with explant height reaching 3.00 ± 0.14 cmunder light and 2.60 ± 0.17 cmunder dark conditions, accompanied by 0.95 shoots and 0.86 roots per explant. No significant interaction between light conditions and TDZ was detected. These findings indicate that early morphogenesis of kopyor coconut embryos is primarily regulated by endogenous hormonal balance, with low TDZ concentrations optimizing growth responses, while light plays a critical role in organ differentiation, particularly in plumule formation. The results provide a basis for improving in vitro propagation protocols for this economically important coconut variant.

Key words:

Cocos nucifera L., in vitro, kopyor coconut, light conditions, morphogenesis, thidiazuron

The effect of ethyl 5′-(4-methoxybenzoyl)-5′,7′-dihydrospiro[cyclopentane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazin]-3′-carboxylate on Pinus sylvestris L. seed germination

Т.А. Kalinina¹, О.А. Vysokova¹, L.А. Khamidullina¹², А.А. Kochubei³, О.Е. Cherepanova³ and Т.V. Glukhareva¹*

¹Ural Federal University named after the first President of Russia B.N. Yeltsin, Mira street 19, RU620002 Ekaterinburg, Russia
²Postovsky Institute of Organic Synthesis UB RAS, Sofia Kovalevskaya street 22, RU620990 Ekaterinburg, Russia
³Botanical Garden UB RAS, 8 Marta street 202a, RU620144 Ekaterinburg, Russia
*Correspondence: taniagluhareva@yandex.ru

Abstract:

Plant growth stimulators are capable of enhancing both agricultural output and the rate of plant maturation, consequently improving the total crop yield and increasing their resistance to disease and adverse environmental conditions. This is why such compounds are used in the cultivation of both agricultural and ornamental plants. The aim of this work was to study the effect of ethyl 5′-(4-methoxybenzoyl)-5′,7′-dihydrospiro[cyclopentane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazin]-3′-carboxylate on Pinus sylvestris L. seed germination. The article describes the synthesis of ethyl 5′-(4-methoxybenzoyl)-5′,7′-dihydrospiro[cyclopentane-1,6′-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazin]-3′-carboxylate and the data from spectral and X-ray crystal analysis. The results of the experimental stimulation of Pinus sylvestris L. seed germination using spiro-1,2,3-triazolo[5,1-b]1,3,4-thiadiazine are given compared to the commercially available phytohormones thidiazuron and 6-benzylaminopurine. The estimation of germination, vitality, healthy seed ratio and cotyledon length indicated that the tested compound at a concentration of 0.5 mg L^-1 had an effect similar to 6-benzylaminopurine: indeed, the speed of germination and fungal invasion rate exceeded the effect of 6-benzylaminopurine.

Key words: