Performance of Putative Mutants and Genetic Parameters of Plectranthus amboinicus (L.) through Mutation Induction With Colchicine

Genetic enhancement in vegetatively propagated crops can be done through mutation induction. Colchicine-induced mutation is one of the methods that can be employed to increase plant genetic diversity. This study aimed to determine the effect of colchicine on the performance and genetic parameters of MV3 generation of Plectranthus amboinicus (L.). This study was conducted at the Laboratory of Agricultural Seed Management, Plantation Research and Development Center, from June 2018 to June 2019. Nodes and shoots were used as explants. Mutation induction was performed using colchicine at concentrations of 0%, 0.02%, 0.04%, and 0.06%. Explant regeneration and subculture were done on MS0 medium. The number of plantlets yielded were 59 (0% concentration of colchicine), 60 (0.02%), 81 (0.04%), and 80 plantlets (0.06%), respectively. Results indicated that colchicine-induced mutation in an in vitro culture was able to generate high genetic diversity in both quantitative and qualitative characters of the plantlets. At the concentration of 0.04%, colchicine produced the highest frequency of putative mutants (28.4%). Genetic parameters in MV3 generation of P. amboinicus plantlets showed that five quantitative characters, i.e. plantlet height, number of leaves, number of shoots, leaf length, and number of roots had high heritability values at a concentration around the LC50 value (0.0275%).

Colchicine Induced Mutation in Nigella sativa Plant for the Assessment of Morpho-Physiological and Biochemical Parameter Vis-A-Vis In Vitro Anti-Inflammatory Activity

Background: Nigella sativa (NS), an herbaceous medicinal plant recognized for its diverse beneficial applications as a spice and traditional medicine. Objective: The present study was targeted to explore the antioxidant potential of Nigella sativa in response to colchicine-induced mutation. The stress condition brought due to mutation may affect the medicinal value (anti-inflammatory activity) of the plant. Method: Nigella sativa seeds were imperiled to colchicine treatment at various concentrations viz. 0.00625, 0.0125, 0.025, 0.05 and 0.1% subjected for analysis. Result: The colchicine treated plant (polyploid/ mutant) at 0.025% concentrations showed significant variation at morpho-physiological and biochemical level with respect to control (p value < 0.05). At the morphological level, the plant showed enlargement of shoot length (33.760±2.295mm), root length (13.546±1.535 mm), and leaf area (22.836±1.524 mm2). The analysis of seeds showed enhanced seeds per pod (49.333±4.163), weight of seeds (2.810±0.010g), length (3.133±0.089mm), and width (1.123±0.044mm) when compared with control. The physiological parameters also showed significant enhancement for stomatal index (35.456±4.751%), chlorophyll A (9.053±0.865 µg/gfw), chlorophyll B (4.990±0.763 µg/gfw), and total carotene content (773.190±5.906 µg/gfw). However, the fresh weight/ dry weight ratio (10.738±3.031) was found to be deprived. Furthermore, biochemical parameters viz. total flavonoid (seeds 1.973±0.134; plant 1.703 ± 0.064 mg eqv QE/g of tissue), total phenolic (seeds 15.690±1.495; plant 8.220±0.070 mg eqv GA/g of tissue), total carotene (seeds nil; plant 773.190±5.906 µg/gfw), and total antioxidant (seeds 0.445±0.102; plant 0.386±0.010 mM eqv AA/g tissue) were significantly elevated at 0.025% of colchicine treatment. When the in vitro anti-inflammatory activity was targeted, a significant escalation was observed for inhibition of albumin denaturation (97.466±2.835%), proteinase inhibitory activity (62.290±6.475%), heat-induced hemolysis (89.873±3.533%), hypotonicity induced hemolysis (92.572±3.527%), anti-lipoxygenase activity (96.010±3.098%), and cyclooxygenase inhibitory activity (68.296±3.920%) at 500µg/mL concentration of extract. Conclusion: Thus, it can be concluded that 0.025% of colchicine can induce significant (p value < 0.05) mutation in the Nigella sativa plant, which may lead to alterations at morpho-physiological and biochemical levels. Such treatment induces stress in the plant and leads to elevated antioxidant levels. This in turn elevates the therapeutic potential of the plant. Hence, our study is a novel and open-ended finding to explore various other medical properties of the plant with respect to colchicine-induced mutation.

Effect of EMS induced mutation in rice cultivar Nagina 22 on salinity tolerance

Salinized hydroponic culture experiment with three salinity levels (EC control, 6 and 12 dS/m) was performed to screen salt tolerant mutants of aerobic rice cultivar Nagina 22 and to study the nature of salt tolerance from a total of 432 EMS induced M4 mutants. Plants were harvested 30 days after sowing. Growth parameters viz. root weight, shoot weight, root length, shoot length, Na and K concentrations in shoot and roots were measured. Combined Factor scores of growth parameters was computed by Principle Component Analysis using Minitab software. At EC 12 dS/m 10 mutants out of 432 were able to survive. At moderate salinity, some mutant lines produced higher shoot weight compared to their respective control showing inverse trend and the effectiveness of EMS induced mutation in inducing salinity tolerance to these mutants. At high salinity only10 mutants survived (remained green) up to the time of 30 days harvest. These mutants performed well in terms of overall growth recording 2.1-2.5 times higher factor score and 8-14 times higher shoot weight compared to the N 22 check. One mutant N22-L-1010 almost completely excluded Na at xylem parenchyma level. Two other mutants N22-L-1013 and N22-L-806 maintained Na exclusion compared to the N22 check. N22 check and mutant N22-L-1009 maintained similar degree of Na exclusion though the N22 check died because it cannot maintain adequate K in shoot. We conclude that EMS has induced salinity tolerance in some mutants. The study can be advanced further to characterize the putative mutants through molecular genetics approaches.