scholarly journals In vitro Ploidy Manipulation for Crop Improvement

2020 ◽  
Vol 11 ◽  
Author(s):  
Darren H. Touchell ◽  
Irene E. Palmer ◽  
Thomas G. Ranney
2021 ◽  
Vol 12 ◽  
Author(s):  
Andrés M. Bellido ◽  
Eduado D. Souza Canadá ◽  
Hugo R. Permingeat ◽  
Viviana Echenique

The available methods for plant transformation and expansion beyond its limits remain especially critical for crop improvement. For grass species, this is even more critical, mainly due to drawbacks in in vitro regeneration. Despite the existence of many protocols in grasses to achieve genetic transformation through Agrobacterium or biolistic gene delivery, their efficiencies are genotype-dependent and still very low due to the recalcitrance of these species to in vitro regeneration. Many plant transformation facilities for cereals and other important crops may be found around the world in universities and enterprises, but this is not the case for apomictic species, many of which are C4 grasses. Moreover, apomixis (asexual reproduction by seeds) represents an additional constraint for breeding. However, the transformation of an apomictic clone is an attractive strategy, as the transgene is immediately fixed in a highly adapted genetic background, capable of large-scale clonal propagation. With the exception of some species like Brachiaria brizantha which is planted in approximately 100 M ha in Brazil, apomixis is almost non-present in economically important crops. However, as it is sometimes present in their wild relatives, the main goal is to transfer this trait to crops to fix heterosis. Until now this has been a difficult task, mainly because many aspects of apomixis are unknown. Over the last few years, many candidate genes have been identified and attempts have been made to characterize them functionally in Arabidopsis and rice. However, functional analysis in true apomictic species lags far behind, mainly due to the complexity of its genomes, of the trait itself, and the lack of efficient genetic transformation protocols. In this study, we review the current status of the in vitro culture and genetic transformation methods focusing on apomictic grasses, and the prospects for the application of new tools assayed in other related species, with two aims: to pave the way for discovering the molecular pathways involved in apomixis and to develop new capacities for breeding purposes because many of these grasses are important forage or biofuel resources.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 789 ◽  
Author(s):  
Temitope Jekayinoluwa ◽  
Jaindra Nath Tripathi ◽  
George Obiero ◽  
Edward Muge ◽  
Leena Tripathi

Banana and plantain are among the foremost staple food crops providing food and livelihood to over 500 million people in tropical countries. Despite the importance, their production is hampered due to several biotic and abiotic stresses. Plant tissue culture techniques such as somatic embryogenesis and genetic transformation offer a valuable tool for genetic improvement. Identification and quantification of phytochemicals found in banana and plantain are essential in optimizing in vitro activities for crop improvement. Total antioxidants, phenolics, flavonoids, and tannins were quantified in various explants obtained from the field, as well as in vitro plants of banana and plantain cultivars. The result showed genotypic variation in the phytochemicals of selected cultivars. The embryogenic cell suspensions were developed for three farmer-preferred plantain cultivars, Agbagba, Obino l’Ewai, and Orishele, using different MS and B5-based culture media. Both culture media supported the development of friable embryogenic calli (FEC), while MS culture media supported the proliferation of fine cell suspension in liquid culture media. The percentage of FEC generated for Agbagba, Obino l’Ewai, and Orishele were 22 ± 24%, 13 ± 28%, and 9 ± 16%, respectively. Cell suspensions produced from FECs were successfully transformed by Agrobacterium-mediated transformation with reporter gene constructs and regenerated into whole plants.


2015 ◽  
Vol 57 (2) ◽  
pp. 9-28 ◽  
Author(s):  
Tasiu Isah

AbstractPlant tissue culture techniques have become an integral part of progress in plant science research due to the opportunity offered for close study of detailed plant development with applications in food production through crop improvement, secondary metabolites production and conservation of species. Because the techniques involve growing plants under controlled conditions different from their natural outdoor environment, the plants need adjustments in physiology, anatomy and metabolism for successfulin vitropropagation. Therefore, the protocol has to be optimized for a given species or genotype due to the variability in physiological and growth requirement. Developing the protocol is hampered by several physiological and developmental aberrations in the anatomy and physiology of the plantlets, attributed toin vitroculture conditions of high humidity, low light levels and hetero- or mixotrophic conditions. Some of the culture-induced anomalies become genetic, and the phenotype is inherited by clonal progenies while others are temporary and can be corrected at a later stage of protocol development through changes in anatomy, physiology and metabolism. The success of protocols relies on the transfer of plantlets to field conditions which has been achieved with many species through stages of acclimatization, while with others it remains a challenging task. This review discusses various adjustments in nutrition, physiology and anatomy of micro-propagated plants and field grown ones, as well as anomalies induced by thein vitroculture conditions.


HortScience ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Qingling Li ◽  
Yuesheng Yang ◽  
Hong Wu

Echinacea purpurea L. is one of the important ornamental and medicinal plant species. Ploidy manipulation is a valuable tool for improving plant quality or production in E. purpurea as well as in many other plants. To study the segregation of pure ploidy plantlets from colchicine-induced ploidy chimeras in E. purpurea, we used a chimera plantlet that consisted of 1.93% diploid, 35.04% tetraploid, and 63.03% octoploid cells as the source material for experiments. The results showed that three factors significantly influenced the segregation, i.e., the component ratios of different ploidy cells in the chimera, the number of sequential passages, and the methods of segregation culture of the chimera plantlets. Other factors, such as explant types (i.e., leaf, petiole, or root) and 6-benzyladenine (BA) concentrations (i.e., 0.2, 0.4, 0.8, and 1.2 mg·L−1) occasionally influenced the segregation. Pure chromosome-doubled polyploids are not easily obtained in various plant species, so segregation culture of ploidy chimeras may potentially be more effective. The morphological characteristic and content of cichoric acid were compared among diploid, tetraploid, and octoploid plants. Results indicated that tetraploid and octoploid plants had more stunted growth, larger stomata, lower stomata frequency, more chloroplast number in guard cells, and higher cichoric acid content than original diploid lines.


2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Kesiraju Karthik

Cotton (Gossypium spp.), is a mercantile crop plant is grown for its fluffy fiber and cotton seed oil in around 70 countries worldwide. Cotton is an economically important crop, shows erratic productivity under rain feed conditions; it is bogged down with many biotic and abiotic stresses. Due to lack of resistant germplasm, crop improvement through conventional breeding practices has been lagging. Genetic engineering offers numerous protocols to engineer plants to overcome stress. Biotechnological intervention for cotton improvement has begun three decades ago. The recalcitrance of cotton to tissue culture has been the major constraint for in vitro regeneration. Alternate methods that evade tissue culture regeneration steps have thus been envisaged. Till date there are very few standardized protocols that can be employed to develop transgenics in a genotype independent manner. Thus, genotype independent in planta transformation strategies have gained momentum in the present days, but reproducibility of reported protocols remains an amigna in many cases. In planta transformations holds prominence due to viability and ease in generation of transgenic cotton plants with in less time. This review focuses on grouping efforts made by different research groups in this senior. Several reports and standardizations have been focused that reports development of transgenic cotton.


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