Sunflower (Helianthus annuus L. 2n=2x=34) belongs to the genus Helianthus, family ‘Asteraceae’, tribe ‘Heliantheae’, subtribe Helianthinae, which includes 20 genera with 67 species. In the world it is cultivated on an area of 23.83 m.ha with the production of 32.16 mt (Anon., 2010). In India it ranks fourth in area (1.48 m.ha) and production (1.00 mt) (Anon., 2010). In India, Karnataka followed by Andhra Pradesh, Maharashtra and Tamil Nadu are the traditional sunflower growing states; Punjab, Haryana, West Bengal and Uttar Pradesh are promising spring sunflower growing states. In Karnataka, sunflower is grown in an area of 1.026 m.ha with annual production of 0.586 mt and productivity of 571 kg/ha (Anon., 2008). The North Karnataka districts contribute a major share to sunflower production in Karnataka. Among them, Bijapur ranks first in area and production followed by Raichur, Gulbarga, Bagalkot and Bellary.

Sunflower is the rich source of edible oil (40%~52%). Sunflower oil is considered as good for health from the point of high concentration of PUFA (linoleic acid 55%~60% and oleic acid 25%~30%) which are known to reduce the risk of coronary diseases. Sunflower is one of the useful contingent crops especially under rainfed cultivation owing to its day neutral nature and tolerance to temperature and soil moisture regimes.

Genetic diversity at genotypic level is the pre requisite for selection of varieties for plant breeding programmes and the diversity can be detected by several means.

Induced mutations have been applied for the past 40 years to produce mutant cultivars in sunflower by changing plant characteristics for significant increase in plant productivity (Jain 2005). Mutagenic treatments, usually on seed, have induced high-oleic, semi-dwarfs and dwarfs, male-sterile plants and other interesting variants such as earliness and seeds with thin hull (Jan and Rutger 1988).

Hence the present study was under taken to estimate the genetic variability studies in M₃ generation of sunflower developed through induced mutagenesis.

Results and Discussion

All the mutants under the study displayed considerable amount of differences in their mean performance with respect to all the characters studied. This had also been exemplified by highly significant mean sum of squares for these traits which indicated that the mutants used for the study were genetically diverse.

The mutants showed a wide range of variation, which provides ample scope for selection of superior and desired mutants by the plant breeders for further improvement of sunflower. An assessment of heritable and non-heritable components in the total variability is indispensable in adopting suitable breeding procedure. The heritable portion of the overall observed variation can be ascertained by studying the components of variation such as coefficients of genotypic and phenotypic variability, heritability and predicted genetic advance.

The phenotypic and genotypic coefficients (Table 1) of variation were highest for plant height, seed yield per plant and oil yield, and moderate for stem diameter, head diameter, seed filling percentage, hundred seed weight, hull content and oil content in M ₃ generation of Morden. In case of DSF 15B mutants (Table 2) GCV and PCV were high for seed yield and oil yield and moderate for plant height, stem diameter, head diameter, hundred seed weight and oil content.

Table 1 Estimates of range, mean and different genetic parameters for yield and yield attributing traits in M3 generation of mutants of sunflower variety Morden

Table 2 Estimates of range, mean and different genetic parameters for yield and yield attributing traits in M3 generation of sunflower variety DSF-15B mutants

Sujatha H. L., Chikkadevaiah, and Nandini., 2002, Genetic variability study in sunflower inbreds. Helia, 25: 93-99
http://dx.doi.org/10.2298/HEL0237093S