Characterization of different tuberose genotypes through DUS testing

Introduction

Tuberose (Polianthes tuberosa L.) is one of the most important tropical ornamental bulbous flowering plants cultivated for production of long-lasting flower spikes. It is popularly known as 'Rajanigandha' or 'Nishigandha'. It belongs to the family Asparagaceae and is native of Mexico from where it was spread to the different parts of the world during the 16 th century. It is commercially cultivated in different parts of India. There are about fifteen species under the genus Polianthes, of which twelve species have been reported from Mexico and Central America. Of these, nine species have white flowers, one is white tinged with red and two are red. Except Polianthes tuberosa L., all the others are found growing wild. The different varieties in tuberose. These are firstly named on the basis of the number of petals they bear. In the cultivar 'Single', the flowers are pure white with only one whorl of corolla segments. The 'Semi double' type, bear white flower with two to three whorls of corolla. The 'Double' type flowers have more than three whorls of corolla. The flower tinged with red in 'double' type is known as 'Pearl'. As flowers are very popular for its strong fragrance and its essential oil is important component for high grade perfume. 'Single' varieties are more fragrant than 'Double'. The high demand for tuberose concrete and absolute in international market which fetch a very good price. Flower of the single type commonly used for extraction of essential oil, loose flower, pot plant, making garland etc. while that of double type are used as cut flower, garden display and interior decoration. Fragrance of flower is very sweet floral and honey like can help give emotional strength. The flower spike of tuberose remain fresh for long time and finds a distinct place in the flower market. Due to its immense export potential, cultivation of tuberose is gaining momentum day by day in India. (Bansil, 2018) [1] . In recent years, crop improvement had play important role in producing new types in tuberose and for that the knowledge of genetic base of crop is must. Morphological characterization is the first step in description and classification. With the advent of Protection of Plant Varieties and Farmers Right Act, 2001in India, the potential application of the DUS test guideline to distinguish a candidate variety from reference material was successfully demonstrated.

Genotype

Half Sibs of Genotype and check G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, G12, G13, G14, G15, G16, G17, G18, G19, G20, G21, G22, G23, G24, G25, G26, G27, G28, G29, G30, G31, G32, G33, G34, G35, G36, G37, G38,G39, G40, G41, G42, G43, G44, G45, G46, G48, G49, G50, G51, G52, G56, G57, G58, G59, G60, G61, G62, G63, G65

Results and Discussion

Morphological characters were prioritized due to their predominant genetic expression and stability across generation. An effort was made to characterise the half sibs of tuberose genotypes exhibiting superior characteristics, including leaf colour, leaf variation, flower colour, flower type, tepal arrangement and flower length. The characterization was made as per PPV and FRA's DUS guideline on tuberose (2013) and presented in Table 2. Moreover, origin of genotypes was also documented and presented in Table 3.

In case of leaf colour, dark green leaves were observed in 51 genotypes viz. Arka Nirantara, Arka Shringar, GKTC-4, Bidhan Jyoti, Bidhan Ujjawal, Mexican Single and other half sibs, however rest of genotypes showed light green coloured leaves which are mentioned in Table 3. Among 70 genotype, Sikkim selection (G 66 ) and G 56 recorded leaf variation whereas, it was absent in rest of the genotypes.

Conclusion

The morphological characterization of seventy genotypes including sixty half-sib and ten checks clearly brought out the difference as per the PPVFRA given DUS guideline.

The data represented indicate that these genotypes differed highly.

References

1. Bansil PC. Floriculture cultivation, processing and marketing. New Delhi (India): Daya Publisher; 2018. p. 211.
2. Anonymous. Guidelines for the conduct of test for distinctiveness, uniformity and stability on tuberose (Polianthes tuberosa L.). New Delhi (India): Protection of Plant Varieties and Farmer's Rights Authority; 2013. p. 1-16.
3. Bharti H, Singh KP, Singh MC. Morphological characterization of tuberose (Polianthes tuberosa Linn.) germplasms using DUS testing. Progressive Horticulture. 2015;47(2):280-287.
4. Naik BC, Kamble BS, Tirakannanavar S, Parit S. Evaluation of different genotypes of tuberose (Polianthes tuberosa L.) for growth, flowering and yield characters. Int. J. Curr. Microbiol. App. Sci. 2018;7(7):4135-4141.
5. Bharti H, Singh KP, Singh R, Kumar R, Singh MC. Genetic diversity and relationship study of single and double petal tuberose (Polianthes tuberosa L.) cultivars based on RAPD and ISSR markers. Indian Journal of Horticulture. 2016;73(2):238-244.