In vitro induction and assessment of tetraploid plants from shoot cultures of diploid Niger (Guizotia abyssinica (L.f.) Cass.): a multipurpose oilseed crop

Mahadev R Chambhare,Tukaram D Nikam

doi:10.1007/s11240-021-02200-5

Mahadev R Chambhare, Tukaram D Nikam

Open Access

https://doi.org/10.1007/s11240-021-02200-5

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Abstract

Agronomic traits improvement in crop plants can be accomplished by induction of polyploidy. Niger (Guizotia abyssinica (L.f.) Cass.) is an important edible oil yielding diploid crop (2n = 30). In the present study, the tetraploidization in niger plants was attempted by treating apical portion (about 2 cm length) of in vitro raised shoots with colchicine and their confirmation by chromosome counting and flow cytometry. The in vitro shoots were raised from leaf explants excise from in vitro germinated seedlings and cultured on MS medium supplemented with 1.0 mg/l BAP (6-benzylaminopurine). The survival and nature of growth of treated shoots was variable with colchicine concentration (0.0, 0.005, 0.01, 0.02, 0.03, and 0.04%) and exposure time (4, 8, 12, and 16 h). The maximum tetraploid induction ratio (38%) was recorded with 0.02% colchicine treatment for 8 h. The chromosome number in root cells of tetraploid plantlets was 2n = 4x = 60 and the DNA content in leaf cells was 10.44 pg which was double to the diploid plant (5.32 pg) cells. In addition, there was significant difference in leaf characteristics of diploid and tetraploid plantlets. Compared to diploid, the tetraploid plantlets showed larger leaves, larger stomatal size, low stomatal index, larger capitula, larger seeds, and a higher number of seeds per capitula. The oil content in seeds was higher and associated with altered fatty acid profile. The results demonstrated that the tetraploid plantlets obtained in this study exhibited some superior agronomical traits (as mentioned above) compared to diploid. The developed protocol and produced tetraploid plantlets will open the new door in improvement of edible oil yielding crop Guizotia abyssinica (L.f.) Cass.

Highlights

The occurrence of polyploid nature improves the capacity of the plant systems to cope up with the variations in the environments
The tetraploidization in Niger plants was achieved by treating apical portion of in vitro raised shoots with colchicine and their confirmation by chromosome counting and flow cytometry
The apical portion of four-week-old in vitro regenerated shoots forms leaf explants were exposed to the treatment of colchicine (Fig. 1)

Summary

Introduction

The occurrence of polyploid nature improves the capacity of the plant systems to cope up with the variations in the environments. Colchicine is an alkaloid functions as antimitotic metabolite It is commonly used for chromosome doubling and for the induction of polyploidy in plant cells. The technique offers an effective condition for mutant treatment, excellent mechanism for the manipulation of ploidy level by minimizing the influence of external factors during the treatment for chromosome doubling, and increases the efficiency of induction of polyploidy. It allows development of improved genotype on in vitro selection, multiplication of mutant and its establishment in the field conditions

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Conclusion