Application Of Colchicine Research Articles

Variability of agromorphological traits in Portulaca grandiflora through induced mutation using colchicine

Abstract. Aisyah SI, Meiningrum NI, Yudha YS, Nurcholis W. 2024. Variability of agromorphological traits in Portulaca grandiflora through induced mutation using colchicine. Biodiversitas 25: 2484-2493. Portulaca grandiflora Hook is an ornamental plant originating from the Portulacaceae family, and it has been extensively cultivated on various continents. P. grandiflora displays appealing flower shapes and vibrant colors suitable for growth in a tropical landscape. Increased morphological diversity carries significant importance in the aesthetic function of ornamental plants. The higher the variation in the morphological characteristics of ornamental plants, the greater the market value of these plants due to their enhanced aesthetic appeal. Additionally, colchicine, a polyploidy-inducing agent, can enhance the plant genetic diversity. This study aims to investigate the impact of colchicine application on the morphological characters of P. grandiflora. The experiment was conducted for four months at the Leuwikopo Experimental Field, IPB, with two factors of Completely Randomized Block Design: The colchicine treatment comprises five concentration levels (0, 0.05, 0.1, 0.15, and 0.2), with four test genotypes: Orange, Peach, Bicolor, and Banana. A significant reduction in growth was observed in the Bicolor genotype, followed by the Banana genotype, indicating varying tissue sensitivities to colchicine treatment. The study reveals variations in morphological responses for each concentration treatment and genotype used. Statistical results confirm aspects: (i) each genotype displays different performance, (ii) the combined treatment of colchicine significantly influences the growth and development of quantitative traits, and (iii) The interaction (colchicine x genotype) was statistically significant for all quantitative characters of P. grandiflora except stem diameter. Qualitative traits, such as morphological changes in stem color, leaf color, and shape, were observed. Three correlation values are positive and statistically significant: plant length and leaf width, number of branches on shoots and leaves, and number of branches on shoots and flowers. Putative mutants of P. grandiflora exhibiting new traits require in-depth exploration in subsequent generations.

Colchicine-Induced Polyploidy in Leguminous Crops Enhances Morpho-Physiological Characteristics for Drought Stress Tolerance.

Legumes play a significant role in the alleviation of food insecurity, maintaining soil fertility, and achieving sustainable crop production under adverse environmental conditions. The increased demand in legume production contemplates that attention on the genetic improvement of these crops through various means such as genetic engineering and mutation breeding should take a centre stage in global agriculture. Therefore, this paper provides a succinct analysis of the currently available literature on morphological and physiological traits in polyploidised leguminous plants to counter the adverse effects of drought stress. The effects of colchicine on various morphological and physiological traits of polyploidised legumes compared to their diploid counterparts were examined. Numerous reports revealed variations in these traits, such as improved root and shoot growth, plant biomass, chloroplastidic content, protein, RNA, and DNA. The differences observed were also associated with the strong relationship between plant ploidy induction and colchicine application. Furthermore, the analysis indicated that polyploidisation remains dose-dependent and may be achievable within a shorter space of time as this antimitotic chemical interferes with chromosome separations in somatic plant cells. The efficiency of this process also depends on the advancement of treatment conditions (in vitro, in vivo, or ex vitro) and the successful regeneration of polyploidised plants for adaptation under drought stress conditions. As such, the improvement in metabolite profile and other essential growth characteristics serves as a clear indication that induced polyploidy needs to be further explored to confer resilience to environmental stress and improve crop yield under drought stress conditions in leguminous plants.

Induction of Ploidy Level on Three Patchouli (Pogostemon cablin Benth) Cultivars by Colchicine In Vitro

Patchouli plants produce essential oils and are used as a raw material and fixative agent for perfumes. The most widely cultivated patchouli plant in Indonesia is Aceh patchouli. Sexual propagation in Aceh patchouli plants is impossible as it does not flower. Genetic diversity can be elevated through another method, such as polyploidy induction using colchicine. This research aimed to evaluate the state-of-the-art application of polyploidization techniques as a breeding tool for callus-based explants. A completely randomized design with a factorial pattern was used in this experiment consisting of two factors, patchouli cultivars (Sidikalang, Tapak Tuan, and Lhokseumawe) and colchicine concentration (0.0%, 0.2%, 0.5%, 0.7%, and 1%). The result showed an interaction between three patchouli cultivars with colchicine concentration on callus size and color characters. In Sidikalang cultivar, 0.2% colchicine concentration affects the character of callus emergence time and has more buds. In cultivar Tapak Tuan, the application of colchicine 0.2% affects the callus size character and has the highest number of buds. In the Lhokseumawe cultivar, giving 0.5% colchicine affects the character of callus appearance time, callus size, and callus color. Concentrations of 0.2% and 1.0% colchicine in Sidikalang and Tapak Tuan calluses increased the number of chromosomes, ranging from 2n (32), 3n (48), and 4n (64). The implication of the research could be disclosure of an opportunity to create a new superior variety.

Stomatal Studies on Colchicine Treated Bajra Napier Hybrids (Pennisetum glaucum x P. purpureum)

Background: This experiment was done to analyze the colchiploids obtained in two bajra napier hybrid genotypes named CO6 and TNCN 1534. Stomatal size is considered as one of the main parameters in analysing the variants developed by colchicine application. Methods: Two methods were adopted for inducing polyploidy BN hybrids. In case of whole immersion method, budded setts were completely immersed in concentrations of 0.05%, 0.10%, 0.15%, 0.20% and 0.25% for 3 and 6 hours duration. In case of the cotton swab method, the nodded setts were covered with a thin layer of cotton and same five concentrations were given continuously for a period of over two days. After transplanting them in the field for 30 days, evaluation of stomatal length and width was done. Result: The stomatal measurements changed with various range of concentrations and the method of application. In the case of whole immersion method, 0.20% and 0.25% concentration for 3 and 6 hours produced variants having largest width and length of stomata and also covered the largest range for mean values. In cotton swab treatment, highest range for stomatal measurements were seen at 0.20% and 0.25% concentrations. The whole immersion method was able to generate a wide range for stomatal length and width as compared to cotton swab method. Hence, it can be deciphered that whole immersion method was more effective than cotton swab method in this study. The highest concentration of 0.25% was the most effective in inducing changes in the treated plants in both the methods. Through this, we were able to identify some putative colchiploids in the study. These screened polyploids were forwarded for further analysis which were then used to identify genotypes having desirable forage and quality parameters.

The Chromosome of Phalaenopsis spp. and Doritaenopsis sp. Hybrid Induced by Colchicine

One way to improve the genetic diversity of orchid plants is by polyploidization using the antimitotic compound colchicine. This research was conducted to determine the ploidy level in several types of hybrid orchids (Phalaenopsis spp. and Doritaenopsis sp.) that applied 1,000 mgL−1 colchicine and to obtain polyploidy orchid yields to improve the genetic diversity of orchid plants. This research was carried out on August 2021 - March 2022 in the Screen House Faculty of Agriculture Universitas Sebelas Maret and Integrated Laboratory Universitas Sebelas Maret. The method of this research uses squash preparation for chromosome analysis with the preparation materials used the meristematic flower bud of Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ which were not treated and has been treated with 1,000 mgL−1 colchicine. Orchid varieties that used as samples were three samples, then each sample had two treatments and was replication two times. There are twelve samples in all. The application of colchicine was made by wetting a cotton swab with 1 ml of colchicine solution in each treatment. Then the buds are wrapped with cotton and covered with carbon paper outside for two days. The results of this research showed that the Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ orchids which were treated with 1,000 mgL−1 colchicine each underwent polyploidization into tetraploid with the number of chromosomes 2n = 4x = 76. Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ have a relative length chromosome length, and have the same chromosome shape, namely metacentric.

Induced polyploidization in buckwheat (Fagopyrum esculentum Moench)

The significance of polyploidy in the evolutionary process of plants history is well documented. In this concern, seed priming with colchicine as well as the cotton-swab method for polyploidy induction in plants becomes much acquainted in cytogenetic study. The aim of present study was to achieve chromosomal doubling by the application of colchicine to apical meristem of young seedlings. The young seedlings were treated with three different concentrations of colchicine (0.2, 0.4 and 0.6%) for durations of 12, 24 and 36 h each. The colchiploidy with highest proportion approximately 50% with 2n=4x=32 was found at 0.2% concentration for 24 and 36 h. Autotetraploid enduring plants were identified with morphological and cytological variations such as thickness of leaf, larger stomata with low density, larger pollen, large flower etc. Buds were selected from these plants for the cytological study. Cytological analysis including chromosome counting demonstrated that the chromosome number was doubled. The confirmation of autotetraploid plants was achieved by this technique. Tetraploid plants were grown up to maturity and the harvested seeds were sown to establish the second generation which may be used in future breeding programme

Network Pharmacology-Based Investigation and Experimental Exploration of the Antiapoptotic Mechanism of Colchicine on Myocardial Ischemia Reperfusion Injury.

Background: The beneficial effects of colchicine on cardiovascular disease have been widely reported in recent studies. Previous research demonstrated that colchicine has a certain protective effect on ischemic myocardium and has the potential to treat myocardial ischemia reperfusion injury (MIRI). However, the potential targets and pharmacological mechanism of colchicine to treat MIRI has not been reported. Methods: In this study, we used network pharmacology and experimental verification to investigate the pharmacological mechanisms of colchicine for the treatment of MIRI. Potential targets of colchicine and MIRI related genes were screened from public databases. The mechanism of colchicine in the treatment of MIRI was determined by protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Additionally, we evaluated the effect of colchicine on H9C2 cell activity using CCK-8 assays, observed the effect of colchicine on H9C2 cell apoptosis via flow cytometry, and further verified the expression of key targets after colchicine treated by Western blot. Results: A total of 626 target genes for colchicine and 1549 MIRI disease targets were obtained. 138 overlapping genes were determined as potential targets of colchicine in treating MIRI. the PPI network analysis demonstrated that the targets linked to MIRI were ALB, TNF, ACTB, AKT1, IL6, TP53, IL1B, CASP3 and these targets showed nice affinity with colchicine in molecular docking experiments. The results of GO analysis and KEGG pathway enrichment demonstrated that the anti-MIRI effect of colchicine involves in apoptotic signaling pathway. Further tests suggested that colchicine can protect H9C2 cell from Hypoxia/Reoxygenation (H/R) injury through anti-apoptotic effects. Western blot results demonstrated that colchicine can inhibited MIRI induced apoptosis of H9C2 cell by enhancing the decreased levels of Caspase-3 in myocardial injure model induced by H/R and activating the PI3K/AKT/eNOS pathway. Conclusions: we performed network pharmacology and experimental evaluation to reveal the pharmacological mechanism of colchicine against MIRI. The results from this study could provide a theoretical basis for the development and clinical application of colchicine.

Possi bilities and perspectives of colchicine application in complex therapy in patients with COVID-19

The new coronavirus infection, which has become a pandemic, is greatly increasing interest in the search for new pharmacological drugs with antiviral and anti-infl ammatory properties. Colchicine, which has been used in medicine for centuries and has been mainly known as arthrifuge, has come to be unexpectedly considered as a drug aff ecting the cumulative endpoint in outpatients, including death and hospitalization requirement in a recent large, well-planned, randomized controlled trial. The article provides data on the pharmacodynamics of the drug, which consists in blockade of infl ammasome activation in patients with COVID-19, and an eff ective impact on the mechanisms of “cytokine storm” — a predictor of acute respiratory distress syndrome and sepsis as a major cause of multi-organ lesions and death. The information that its spectrum of anti-infl ammatory activity may explain the vasoprotective eff ects in patients with coronary heart disease (CHD) who underwent acute infarction in the COLCOT study, is particularly attractive from the point of view of the perspectives for the oral colchicine application in COVID-19. High tolerability of the drug, the absence of severe adverse reactions, simple dosing regimen, low cost of colchicine, the absence of signifi cant drug interactions are additional advantages. The authors of this article believe that this information is suffi cient for planning a study of the eff ectiveness of colchicine as an element of complex therapy in hospitalized patients with COVID-19 in combination with acute coronary syndrome, including the need for percutaneous coronary intervention. Early anti-infl ammatory therapy in patients with COVID-19 is still not recommended, despi te th e fact t h at there comes an understanding of its necessity. And in this situation, colchicine has the potential to challenge.

Induction of polyploidy through colchicine in cotton (Gossypium herbaceum) and its conformity by cytology and flow cytometry analyses

Cotton is one of the most important fibre crops in the world. An increase in ploidy level was observed in diploid cotton species namely Gossypium herbaceum in the experiment, through colchicine application. There were significant growth variations noticed during the induction of polyploidy in the cotton plants depending upon the concentration of colchicine, duration of the treatments and genotypes taken. An increase in the concentration of colchicine or the duration of the treatment had a retardation effect on seed viability in G. herbaceum. The hypocotyls of length between 4 and 8 mm were found to be most responsive to colchicine treatment. The root meristem of G. herbaceum, treated with 0.2 and 0.4% colchicine exhibited the most number of tetraploid cells during 16 h of treatment. The increase in the concentration of colchicine, along with an increase in duration of treatment led to the chromosomal abnormalities in the wild cotton species. Seed treatment for colchicine application, was the most efficient and reliable method when compared to Petri-plate application and cotton swabbing treatments for inducing polyploidy in diploid cotton.

THE CYTOLOGICAL AND CYTOGENETIC STUDY OF THE ALTERNATED FORMS OF ALFALFA

Colchicine in experimental mutagenesis is used to induce polyploidy, since it, by destroying the division spindle, prevents chromosomes from separating. The importance of studying the mutagenic effect of colchicine on a plant cell is also determined by the practical application of colchicine in the enrichment of plant genetic resources of plants, the creation of cytogenetic collections and their use in breeding programs. In our experiments, we studied the effect of colchicine on alfalfa and the effect of its influence. Seeds of varieties ASKHI-1 and AzNIKHI-262 obtained as a result of treatment with different concentrations of colchicine (0.02% and 0.04%) were used as plant material. In some anaphases, chromosome delays were observed when diverging to the poles. No cells with a doubled set of chromosomes were found. According to the results of studying the stages of mitosis, it should be noted that ASKHI-1 variety is more sensitive to colchicine treatment than AzNIKhI-252, since the first variety showed significantly greater deviations from the control and another variety at the stage of mitotic activity.

The phenotypic appeal of lily (Lilium longiflorum Thunb.) prompted mutation by colchicine

One of the efforts to assemble high yielding varieties is to use a chemical mutation method, such as colchicine. The objective of this study was to examine the phenotypic appeal of lily convinced by colchicine to acquire a current application and interval of the period for soaked colchicine. The research was steered in the investigational research place of Institute for Vegetable Research (IIVR) at Tongkoh, Sub-District Dolat Rakyat, District Karo, North Sumatera, and Plant Tissue Culture Laboratory, Agriculture Faculty, Universitas Sumatera Utara, from July 2019 up to March 2020. The research castoff Randomized Block Design technique (Factorial-RBD) by two factorials, i.e.: application of colchicine (0, 100, 200, and 300 ppm) and the interval of time for soaked colchicine (3, 6, 9, and 12 h). The constraint experimental was the plant tallness, the span of bud after flourishing, and the width of bloom. The outcome of this study indicated the concentration of colchicine hip 300 ppm (K3) devours pointedly influenced on the plant tallness in the first week until sixth weeks when planting and the concentration of colchicine in 100 ppm (K1) has considerably influenced on the size of bud after flowering and the span of bloom.

Effects of shoot tip colchicine applications on some grape cultivars

Polyploidization can provide changes in vital features such as growth, development, environmental stress tolerance in plants. Colchicine is one of the most commonly used chemicals as a polyploidization agent. In this study, 2-year-old ‘Ekşi Kara’, ‘Gök Üzüm’ and ‘Trakya İlkeren’ (2x, Vitis vinifera L.) saplings grown on their own roots were used. When the enforced shoots reached about 15 cm length, colchicine applied (0, 2.5 g L-1, 5 g L-1, 7.5 g L-1) 24 and 48 hours to the lateral shoot tips. The effects of treatments were evaluated by shoot tip viability, stoma size and density, chloroplast counts, and flow cytometry (FC) analysis, and ‘Kyoho’ (4x) used as control. The maximum stomatal variations were determined in Ekşi Kara cultivar at 2.5 g L-1 24-h application. Based on morphological differences, FC analysis was performed only in ‘Ekşi Kara’ but, there was no genomic duplication. Since the morphological differences were not sufficient in the diagnosis of polyploid in grape cultivars, FC analysis should be performed to achieve confirmed results.

Optimization of chromosome doubling treatment for efficient in vivo doubled haploid production in maize

Abstract An investigation to optimize the protocol for application of colchicine for enhancing the doubled haploid production in maize was done. 106 maize genotypes were used as maternal parents, whereas, pollen source involved tropically adopted haploid inducer (TAIL P1 and TAIL hybrid). After the elimination of chromosomes of inducer lines, haploid seeds were obtained from the crosses. Haploid seedlings were treated with three different doses, such as 0.04, 0.06 and 0.08 per cent of colchicines for different durations (8, 12 and 15 hours). The response of various colchicine concentrations applied for different time durations revealed significant differences at P ≤ 0.05 for various parameters viz., per cent plants survivability, stalk colour, the fertility of tassel, silk present/absent, pollen viability, seed set and per cent doubled haploid formation. In maize, colchicine doses of 0.04 per cent for 12 hours and 0.06 per cent for 8 hours, respectively were established as optimum for enhanced doubled haploid production. But among these two, 0.04 per cent for 12 hours was observed to be best dose for doubled haploid production in maize.

Impact of colchicine on leaf morphology and stomatics of Kalanchoe tubiflora (Harv.) Raym.-Hamet (Crassulaceae)

The demand of medicinal plants for consumption is greatly increasing worldwide. The conventional breeding programs are generally dependent on the environment prone to biotic and abiotic stresses. These added to the low content of secondary metabolites at harvest, bring the need for artificial development of polyploid individuals as an alternative to increase productivity. Consequently, the present study evaluated the effect of different colchicine concentrations and exposure time, on Kalanchoe tubiflora leaf morphology and stomata. Initially, K. tubiflora seedlings were harvested and submitted to colchicine concentrations of 0, 0.025, 0.05 and 0.1 % and at two exposure times (24 and 48 hours). Subsequently, morphological measurements such as plant height, leaf width, leaves number, leaf length, leaf thickness and leaf volume every 15 days were made for 16 weeks after planting. Then, the stomata were characterized, taking into account the width, length, stomatal index and the number of chloroplasts per stoma. A significant increase in leaf morphology was found in colchicine treatments of 0.025 % at 48 h and 0.1 % at 24 h. A significant increase in stomatal morphology with the treatment of 0.025 % at 24 h was also recorded. This shows that the correct application of colchicine in term of quantity and time could produce greater growth in a short period and increase the biomass of K. tubiflora medicinal plant.

Колхицин у пациентов с ишемической болезнью сердца: новые возможности снижения остаточного воспалительного риска

Inflammation plays an important role in atherosclerotic plaque destabilisation and the development of cardiovascular complications. Suppression of its activity in order to reduce residual inflammatory risk in atherosclerotic cardiovascular diseases remains an urgent and unresolved problem to the date. Over the recent years, evidence of the effectiveness of such an approach in secondary prevention of coronary heart disease has been obtained. The purpose of this review was to analyse modern literature on the effect of anti-inflammatory therapy with colchicine on the prognosis of patients with coronary heart disease. The review was carried out using the search for papers published in the PubMed and ClinicalTrials databases within the period from 2007 to 2021. The search was carried out using the keywords «colchicine», «inflammation», «atherosclerosis», «coronary heart disease» and «acute coronary syndrome». The anti-inflammatory and antiatherogenic effects of colchicine are discussed. The paper presents results of studies devoted to the use of colchicine in chronic and acute coronary syndrome, including the key ones LoDoCo2 (2020) and COLCOT (2019) which provided evidence of the effect of the drug on the disease outcome. The issues of safety and prospects of colchicine application in clinical practice for reduction of the residual inflammatory risk in patients with coronary heart disease are addressed.

Increasing Ploidy Level of Garlic (Allium sativum L.) “Tawangmangu Baru” In-Vitro Using Colchicine


 
 
 “Tawangmangu Baru” garlic variety is known to have low productivity. The variety is still highly demanded due to its strong flavour and aroma; however, its production has not yet been able to fulfill the local needs of Central Java due to the small size and limited production area. This study aimed to determine the effect of concentration and time duration of colchicine treatment towards increasing the ploidy level of “Tawangmangu Baru” garlic variety for genetic variability. The experimental design used in this study was a complete randomized design with two factorials and 12 combinations. The first factor was concentration of colchicine, i.e. 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10%, and the second factor was the immersion time, i.e. 24 and 48 hours. The result indicated that, 4.72% callus induction was obtained in BDS + 0.4 mg.L-1 2,4-D + 2.0 mg.L-1 kinetin; and 4.0% callus proliferation were obtained in both BDS + 1.5 mg.L-1 2,4-D + 1.0 mg.L-1 kinetin and MS +1.5 mg.L-1 2,4-D and 1.0 mg.L-1 kinetin. The untreated plantlets showed higher mortality rate compared to the explants with 48 hours colchicine treatment. Higher number of shoots were recorded in 0.1% colchicine at 48 hours and lower shoots in 24 hours, whereas 0.1% colchicine at 24 and 48 hours showed the highest ploidy level of total nuclear DNA analyzed by flow cytometry. The genetic diversity of the “Tawangmangu Baru” garlic was successfully enhanced by colchicine and immersion treatment. Mutant lines with tetraploid and mixoploid plants were obtained. The putative lines obtained at 0.1% colchicine treatment were subcultured to produce new mutants before testing the phenotype. The application of colchicine at 24 and 48 hours treatment improved the genetic potential of “Tawangmangu Baru” garlic variety in vitro. The application of colchicine increased the ploidy level and an increase in ploidy is expected to make the bulb size larger. Larger tuber size will increase the tuber weight, and also the overall garlic productivity and production in the future.
 
 

Colchicine increases intestinal permeability, suppresses inflammatory responses, and alters gut microbiota in mice

Although colchicine (COL) has been used to treat gout for more than a thousand years, it has been shrouded in a dark history for a long time due to its high toxicity, especially for the gastrointestinal tract. With the widespread clinical application of COL, COL’s toxicity to the gastrointestinal tract has raised concerns. This study’s objective was to address the exact intestinal toxicity of COL, with particular attention to the effects of COL on gut microbiota homeostasis. The mice were exposed to various dosages of COL (0.1, 0.5, and 2.5 mg kg−1 body weight per day) for a week, and the results showed that COL exposure caused serious intestinal injuries, reducing the relative expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and tight junction proteins (zo-1, claudin-1, and occludin) in the ileum and colon tissue. The 16S rRNA gene sequencing analysis of mice feces samples revealed that the composition and diversity of intestinal microbiome underwent a profound remodeling at the dosage of 2.5 mg kg−1 body weight per day, which may increase the toxic load in the gut. In addition, elevated levels of diamine oxidase (DAO) and lipopolysaccharide (LPS) in serum indicated that COL increased intestinal permeability, impairing intestinal barrier. In conclusion, our results demonstrate that COL’s toxicity to the gut microbiome is compatible with intestinal injuries, inflammatory pathway inhibition, and increased intestinal permeability; our results also represent a novel insight to uncover the adverse reactions of COL in the gastrointestinal tract.

The Functional State of the Photosynthetic Apparatus of Potato Plants upon Destruction of the Tubulin Cytoskeleton

We have investigated the effect of colchicine, a disrupting agent of the tubulin cytoskeleton, on chlorophyll fluorescence parameters, the Hill reaction, noncyclic photophosphorylation, and the lipid peroxidation reaction in Solanum tuberosum grown in soil in a greenhouse environment. The destruction of microtubules caused an increase in the content of lipid fatty acid hydroperoxides, the primary product of lipid peroxidation, and led to changes in fluorescence parameters: F0 increased, Fm and the maximum quantum efficiency of PSII (Fv/Fm) decreased, and the dissipation of electronic excitation energy as heat increased. Simultaneously, it was found that the Hill reaction rate and the intensity of the process of noncyclic photophosphorylation decreased. The results obtained in this work are discussed in view of the destruction of the integrity of the chloroplast membrane and changes in chlorophyll fluorescence parameters due to colchicine application, as well as in light of our previously obtained data on the change in the content of phytohormones and their concentration ratios in potato leaves when microtubules are destroyed.

Estudio de los factores limitantes para la obtención de plantas haploides de Coffea arabica.

El desarrollo de un método eficiente para obtener plantas haploides de café requiere del estudio de los factores más limitantes. En este trabajo se evaluó el desarrollo de los gametos masculinos en relación con el estado fenológico de la flor de C. arabica, se evaluaron tratamientos de desinfección de las flores, tratamientos para el aislamiento y purificación de las microsporas, se estudió el efecto térmico sobre la inducción de la androgénesis y, por último, se evaluaron tratamientos con agentes antimitóticos para la duplicación cromosómica de tejidos haploides. Para inducir el proceso de androgénesis, se determinó que los botones florales entre 1,0 y 1,7 cm de longitud contenían el mayor porcentaje de células gaméticas en los estados uninucleado tardío y binucleado temprano, cruciales para el cambio ontogénico. Se determinó que el menor porcentaje de contaminación microbiana y oxidación biológica se logró con el uso de hipoclorito de calcio combinado con antioxidantes. El aislamiento y purificación de las microsporas se obtuvo mediante maceración mecánica de las anteras y filtración de las células gaméticas en mallas de 40 y 70 micras junto con el empleo de Percoll en gradientes superiores al 50%. La mayor inducción androgénica de las microsporas se consiguió incubando los botones florales desprendidos de la rama a 4°C, observándose divisiones celulares y formación de colonias multicelulares. La aplicación de Colchicina (1%) a meristemos de plantas haploides de C. arabica permitió la obtención de ramas con hojas que duplicaron su material cromosómico y cambiaron su morfología.

In vivo colchicine manipulation for enhancing DH production efficiency in Triticum durum using Imperata cylindrica-mediated chromosome elimination approach

Durum wheat × Imperata cylindrica hybridization was carried out utilizing two durum wheat genotypes as maternal parents (A-9-30-1 and PDW 314) and I. cylindrica as a pollen source followed by in vivo application of colchicine to establish a standard protocol for colchicine application aimed at enhancement of doubled haploid production in durum wheat. Various concentrations of colchicine ranging from 500 to 7000 ppm were injected to the pollinated spikes at different time interval viz., 24 h, 48 h and 72 h after pollination. Application of 5000–7000 ppm colchicine at 48 h after pollination was established as the optimum colchicine dose for chromosome doubling as confirmed through cytological studies in durum wheat using I. cylindrica-mediated chromosome elimination approach. PDW 314 was identified as a durum wheat genotype having more potential for doubled haploid induction via in vivo colchicine application than A-9-30-1. Identification of optimum dose of colchicine for application at in vivo level for induction of doubled haploids has opened new vistas in durum wheat improvement programme.