Morphogenesis In Tissue Cultures Research Articles

Morphogenesis in Tissue Culture of Local Kazakh Cotton Varieties

Callus was initiated from hypocotyl and cotyledon explants of seven of commercial Kazakh cotton cultivars on MS medium supplemented with 0,1 mg L-1 2,4-D and 0,5 mg L-1 kinetin. The percentage of callus formation ranged from 64,0 to 91,0% for cotyledons and from 72 to 90% for hypocotyls. Study of morphological heterogeneity peculiarities of metamorphosis and histological structure of calli of cotton allowed to identifying seven tissues types and selecting the morphologically stable and perspective callus type for embryogenesis. Significant differences between the calli types of cotton were found by histological and morphological comparative analysis.

TDZ and 4-CPPU Induce Embryogenic Response on Scalps of Recalcitrant East African Highland Banana

Breeding of banana conventionally is very difficult due to high levels of sterility arising from aneuploidy. Transformation of East African highland banana (EA-AAA banana) has been limited by difficulties in induction of embryogenic callus and/or embryogenic cell suspension (ECS), a requirement for efficient genetic transformation. In this study N-phenyl-N’-1,2,3-thidiazol-5-ylurea (TDZ) and N-(2-chloro-4-pyridyl)-N’-phenylurea (4-CPPU) that are highly active in regulating morphogenesis in tissue culture of many plant species were tested for enhancing embryogenic callus induction in recalcitrant EA-AAA banana through scalps. In vitro derived shoot-tips of banana cultivars Mbwazirume, Mpologoma, Nakabululu, Nakinyika and Nfuuka were subcultured on various combinations of TDZ and 4-CPPU till scalps were formed. In all the cultivars, ideal scalps for callus induction were achieved in over 50% of the shoot-tip cultures within four subculture cycles in the medium containing equal proportions of 9–13 µM of TDZ and 4-CPPU, and 26 µM of each. Embryogenic callus was formed on 2.5–20% of the scalp cultures depending on cultivar and, TDZ and 4-CPPU combination. Cultivars Nakinyika, Nakabululu, Mbwazirume and Nfuuka developed regenerable embryogenic callus. Of the plantlets regenerated 5 out of 12 and 4 out of 5 plantlets of cultivars Nakinyika and Mbwazirume, respectively, developed normal roots and were weaned onto soil. These results suggest that TDZ and 4-CPPU increases embryogenic response from scalps of EA-AAA banana which can enhance their genetic transformation.

Effects of plant growth regulators on growth and morphogenesis in tissue culture of Chondracanthus chamissoi (Gigartinales, Rhodophyta)

Chondracanthus chamissoi (C. Agardh) Kutzing (Gigartinales, Rhodophyta) is an edible species and commercialised for carrageenan production in Chile. Investigations on growth and development are needed to improve its cultivation; therefore, this study aims to evaluate the effects of plant growth regulators (PGRs) on its growth and morphogenesis. PGRs tested were two auxins [indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D)] and one cytokinin (benzylaminopurine (BA)) in concentrations of 0.5, 5.0 and 50.0 μM. These PGRs were added to seawater enriched with half strength of von Stosch solution and were gelled with 0.6 % agar, and treatment control (without PGR addition) was conducted simultaneously. Apical and intercalary segments were used as initial explants. Each treatment was tested with six replicates of five axenic explants, and statistical analyses were performed. After culturing in a solid medium for 10 weeks to induce growth and callus formation, explants were cultured in liquid medium with the same experimental conditions for 10 weeks. Effects of auxins (IAA and 2,4-D) and the cytokinin BA on growth rates of apical segments of C. chamissoi were not significant, while low concentration of IAA stimulated the growth of intercalary segments. On the other hand, high concentrations of BA and IAA stimulated the callus formation in apical and intercalary segments, respectively. In liquid medium, PGR did not have a significant effect on growth rates of apical segments, while 2,4-D in concentrations from 0.5 to 50.0 μM stimulated growth of intercalary segments, and formation of lateral branches was stimulated by low 2,4-D in apical segments. These results suggest that PGRs have a regulatory role on callus formation and growth of specific explants of C. chamissoi. Furthermore, the formation of lateral branches stimulated by auxin could be used for seedling production under controlled conditions and could improve the micropropagation and cultivation of C. chamissoi in the Chilean coast.

Steroid substances in the Yucca gloriosa L. cell and tissue culture and their formation during morphogenesis

Comparative study of steroid substances of cell culture and intact plant of Yucca gloriosa L. as well as stepwise morphogenesis in tissue culture of this plant, showed epigenetic changes during cell dedifferentiation. Suspension culture of Yucca gloriosa L. contained free sterols 0.06%; in the bud cells of intact plant where they had been found originally, they amounted to 0.04%. Sitosterol is the dominant component of sterols. Change in the sitosterol-to-other sterols ratio was observed in suspension cells as compared to the intact plant. Unlike differentiated tissue in the suspension cells of Yucca gloriosa L. oligofurostanoside-specific β-glucosidase activity was absent, this explained the presence of only furostanol glucosides in them. Dedifferentiation changes both qualitative and quantitative composition of sapogenins. Instead of smilagenin, hecogenin is synthesized in callus and suspension cells of Yucca gloriosa. The ability to accumulate steroid glycosides directly depends on anatomic differentiation during plant regeneration from callus tissue. The composition and quantity of steroid glycosides and sapogenins characteristic of the intact plant of Yucca gloriosa L. are restored in the regenerated plant.

Callus proliferation and morphogenesis in tissue cultures of Arabidopsis thaliana L

The growth and proliferation pattern of callus derived from seed and the pathways of in vitro morphogenesis in Arabidopsis thaliana were investigated. Callus induced and maintained on Gamborg's B 5 medium containing 20 g/l sucrose, 0.5 mg/l (2,4-dichlorophenoxyacetic acid (2,4-D) and 0.05 mg/l kinetin was shown to contain numerous nodules. Meristematic centres which are characterized by their small, highly cytoplasmic cells are situated in the peripheral regions of the nodular callus. The meristematic centres proliferated to give rise to new callus-containing nodules, or differentiated into roots when the culture conditions were conducive to rhizogenesis, i.e. transfer of the nodular callus onto a medium either devoid of auxin, or with a low indoleacetic acid (IAA) level. The pathway of root formation from the meristematic centres within the nodules is described. In addition green nodules developed within callus placed on a medium containing 0.1 mg/l IAA and 1.0 mg/l kinetin. These nodules subsequently differentiated into leaves and plantlets. Adventive embryoids in globular, heart-shaped and torpedo-shaped stages which subsequently developed into plantlets were also observed. The origin and development of the somatic embryos is discussed.

Diverse pathways of morphogenesis in tissue cultures of the compositeBrachycome lineariloba (2n=4)

Callus lines derived from two A races of the Australian compositeBrachycome lineariloba, have been shown to maintain their diploid complements of only four chromosomes, and also (in one case) a stable potential for embryogenesis, after more than twelve months ofin vitro propagation. Time course comparisons of the decline in frequency of embryogenie and rhizogenic organisation, and the fact that cytodifferentiation is observed even when the formation of multicellular structures cannot be induced, suggest a scheme in which the potential for generating complex structures disappears before the ability to produce simple ones.

Morphogenesis in Tissue Cultures of Different Organs of Nigella sativa

AbstractCalli were isolated from root, stem and leaf segments of Nigella sativa (Fam. Ranunculaceae) on White's medium containing napthaleneacetic acid and coconut milk. From all the three types of calli, roots were differentiated. Shoot development occurred in stem and leaf calli only after the omission of first coconut milk and then of auxin from the basal medium and also in IAA (2.0 mg/ml) and coconut milk (15 % v/v) in the medium. Frequency of organ formation and the maintenance of this capacity depend upon the nature as well as the age of the callus tissue.

Growth and Morphogenesis in Tissue Cultures of Anagallis arvensis

AbstractMorphogenesis has been induced in excised organs and callus tissue cultures obtained from various parts of the seedling and mature plants of pimpernel (Anagallis arvensis). Vigorously growing cell cultures capable of being periodically subcultured have been established in liquid as well as on the agar‐solidified Murashige and Skoog's medium supplemented with 2,4‐D (0.1 mg/1) + kinetin (0.1 mg/l) + coconut milk (10%). The callus tissue obtained from excised hypocotyl segments is white, soft, friable and fast growing, and has been subcultured over a period of two years without showing any sign of decline in growth. The optimum conditions for growth are at pH 5.9, temperature 27°C, and with 4% sucrose as the carbon source. Under appropriate nutritional supply these cultures can be manipulated to induce rhizogenesis in the suspension cultures, and buds and “embryo‐like” structures on agar‐solidified media.The excised leaves, hypocotyl and stem segments regenerate buds. Of the cytokinins used, 6‐(y,y‐dimethylallylamino)‐purine proved to be the best for the number of cultures producing buds, as well as for the number of buds per culture. Anatomical studies revealed that buds arise from the epidermal and subepidermal layers of leaves and hypocotyl; these buds form shoots which eventually develop into plantlets.

Induced morphogenesis in tissue cultures of Solanum xanthocarpum

Differentiation of shoots and roots or unorganized proliferation could be induced in tissue cultures of Solanum xanthocarpum when callus tissues habituated to a medium containing 2.4-D and meso-inositol were transferred to an auxinfree medium or to a medium in which the ratio of auxin and meso-inositol had been altered.