Mass Production of Bananas and Plantains (Musa spp.) Plantlets through in vitro Tissue Culture Partway: A Review

Bananas and plantains are among the most important food crops in Central and West Africa. Their plantation is lead to many problems. In the recent decades, biotechnology tools using in vitro culture technics are used for the mass and free disease plantlets production in order to increase the bananas production and the yield. The main way of in vitro tissue culture at this end is the direct organogenesis i.e., the ability of plant tissues to form various organs de novo by shoots or roots induction to differentiate from a cell or cell clusters. This review aims to summarize the main results obtained in the organogenesis of bananas and plantains (Musa spp.) under in vitro conditions and to identify the challenges during the process. The research articles used in this review show that micropropagation is a reliable alternative to conventional production system of bananas and plantains planting material. However, the use of the in vitro micropropagation for bananas and plantains entails choosing the optimal explant type and size according to objectives. Benzylaminopurine remains the preferred cytokinin for in vitro banana and plantain shoot proliferation, while the use of thidiazuron appears to be more and more common. Whichever cytokinin used, the optimal cytokinin concentration for shoot proliferation is genotype dependent. This review also focuses on the causes and control measures of the two major banana and plantain micropropagation constraints: lethal tissues browning/darkening and microbial contaminations. It showed that applying the suitable and available control measure, according to the evolution of culture, is necessary. All this available information on the in vitro conditions makes banana and plantain cultivars in vitro organogenesis possible.

Understanding In Vitro Tissue Culture-Induced Variation Phenomenon in Microspore System

In vitro tissue culture plant regeneration is a complicated process that requires stressful conditions affecting the cell functioning at multiple levels, including signaling pathways, transcriptome functioning, the interaction between cellular organelles (retro-, anterograde), compounds methylation, biochemical cycles, and DNA mutations. Unfortunately, the network linking all these aspects is not well understood, and the available knowledge is not systemized. Moreover, some aspects of the phenomenon are poorly studied. The present review attempts to present a broad range of aspects involved in the tissue culture-induced variation and hopefully would stimulate further investigations allowing a better understanding of the phenomenon and the cell functioning.

Barley somatic embryogenesis-an attempt to modify variation induced in tissue culture

Background Somatic embryogenesis is a phenomenon carried out in an environment that generates abiotic stress. Thus, regenerants may differ from the source of explants at the morphological, genetic, and epigenetic levels. The DNA changes may be the outcome of induction media ingredients (i.e., copper and silver ions) and their concentrations and time of in vitro cultures. Results This study optimised the level of copper and silver ion concentration in culture media parallel with the induction medium longevity step towards obtaining barley regenerants via somatic embryogenesis with a minimum or maximum level of tissue culture-induced differences between the donor plant and its regenerants. The optimisation process is based on tissue culture-induced variation evaluated via the metAFLP approach for regenerants derived under varying in vitro tissue culture conditions and exploited by the Taguchi method. In the optimisation and verification experiments, various copper and silver ion concentrations and the different number of days differentiated the tested trials concerning the tissue culture-induced variation level, DNA demethylation, and de novo methylation, including symmetric (CG, CHG) and asymmetric (CHH) DNA sequence contexts. Verification of optimised conditions towards obtaining regenerants with minimum and maximum variability compared to donor plants proved useful. The main changes that discriminate optimised conditions belonged to DNA demethylation events with particular stress on CHG context. Conclusions The combination of tissue culture-induced variation evaluated for eight experimental trials and implementation of the Taguchi method allowed the optimisation of the in vitro tissue culture conditions towards the minimum and maximum differences between a source of tissue explants (donor plant) and its regenerants from somatic embryos. The tissue culture-induced variation characteristic is mostly affected by demethylation with preferences towards CHG sequence context.

In vitro tissue culture and genetic analysis of two high-CBD medical cannabis (Cannabis sativa L.) breeding lines

The species Cannabis sativa L. has recently witnessed a resurgence of interest all over the world due to its multipurpose applications and the scientific confirmation of its pharmacological properties. Genotypes with high cannabinoid content are appreciated in the pharmaceutical and cosmetic industries due to their therapeutic potential. These genotypes, with predominantly high cannabidiol (CBD) content, are the subject of research and breeding in several programs, but to date, little data is published on the in vitro tissue culture of cannabis. Our study focused on the establishment of an efficient micropropagation method for two high-CBD breeding lines (MX-CBD-11 and MX-CBD-707) as the basis for advanced biotechnological breeding approaches. The results demonstrated that the in vitro culture of medical cannabis can be initiated on different culture media, that cultured plants can be successfully acclimatized, and that nodal position, and especially the genotype, have a significant influence on the success of shoot culture establishment. They showed that the published tissue culture media optimized for one high-THC strain of Mexican cannabis are not as efficient for other genotypes of (medical) cannabis. We complemented this research with a genetic study of 95 plants of the two breeding lines with 16 microsatellite (SSR) markers which clustered the plants based on breeding line. The results demonstrated that only 8 markers are needed for discrimination of all analyzed plants and their usefulness for clonal identification.

In vitro tissue culture, preliminar phytochemical analysis, and antibacterial activity of Psittacanthus linearis (Killip) J.K. Macbride (Loranthaceae)

Hemiparasitic plants commonly known as mistletoe (muérdago in Spanish) in the families Santalaceae and Loranthaceae are common in various kinds of plants or trees, and many hemiparasitic plants are used for medicinal purposes in various parts of the world. The objective of the present work, carried out in Psittacanthus linearis (suelda con suelda), a representative species in the seasonally dry forest (SDF) from the north of Perú, was to study aspects of in vitro tissue culture, carry out preliminary phytochemical analysis, and assess antibacterial activity. Seeds of individuals of P. linearis, which used Prosopis pallida (algarrobo) as host plant, were collected and used to induce in vitro seed germination, clonal propagation, callus induction and organogenesis. Stems, leaves and fruits of individuals of P. linearis were dried, powdered, and subjected to ethanol extraction. Posteriorly the extract was first recovered with ethanol and the remnant with chloroform, which formed the ethanolic and chloroformic fraction. A preliminary phytochemical screening was performed and preliminary antibacterial studies with Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were carried out and their results are discussed. This is the first report about in vitro tissue culture, phytochemical analysis and antibacterial activity of P. linearis. The results may have important implications for understanding physiological and biochemical interactions between host and hemiparasitic species as well as P. linearis with P. pallida and other SDF species.