Combining ability analysis in linseed (Linum usitatissimum L.)

Introduction

Linseed is an important rabi oilseed crop chiefly grown under rainfed (63%), utera (25%) and irrigated (12%) conditions. In India, it is predominantly cultivated as an oil seed crop under the sole cropping or utera cropping system. 25-30 °C temperature is good for the germination of seed and approximately 15-20 °C during seed formation. But the crop grown for fiber requires still lower temperature (10-19 °C) and high humidity (76%) the crop is susceptible to frost. It is grown best in well drained, fertile silt loam, clay loam and silt clay soil. It grows well in soil having pH ranging from 5 to 7. A row spacing of 20-30 cm with a plant spacing of 7-10 cm is ideal for getting good production. General seed rate of linseed depends on the method of sowing i.e., 40 kg/ha for line sowing and 60 kg/ha for broadcasting method. Seed rate for growing fiber crop is 60 to 80 kg/ha. Linseed is cultivated in monocropping, intercropping and sequence cropping and Paira/utera cropping. Linseed can be grown in fields where other crop may fail to grow. In rainfed areas linseed is generally grown as intercrop with lentil, wheat, chickpea, barley, safflower etc. Nutrient and moisture stress conditions are the main reason for the low productivity of linseed in India. Line × tester analysis is one of the most powerful tools for predicting the general combining ability (GCA) of parents and selection of suitable parents and crosses with high specific combining ability (SCA). Line × tester analysis provides information about combining ability effects of genotypes and also, knowledge regarding genetic mechanism controlling yield components. Information of general and specific combining abilities influencing yield and its components has become increasingly important to plant breeders to select appropriate parents. Combining ability analysis is one of the most powerful tools for estimating combining ability variation and effects in order to pick desirable parents and crosses for heterosis exploitation. For estimating genetic control of a certain trait. Estimates of additive and non-additive gene action obtained using this technique may be valuable in establishing the commercial viability of heterosis and pure line isolation. Gene action is a theory that evaluates allelic interactions for characteristics that show phenotypic behavior and lead to perfect trait selection (Nirala et al., 2018) [9] .

International

Objectives

Recognizing the benefit and desire for "Combining ability analysis in linseed (Linum usitatissimum L.)" the following objectives were managed at Research-Cum-Instructional-Farm, Department of Genetics and Plant Breeding, College of Agriculture, Indira Gandhi Vishwavidyalaya, Raipur, Chhattisgarh during the Rabi 2021-22 & 2022-23 season. 1. To estimate the relative magnitude of general combining ability. 2. To estimate the relative magnitude of specific combining ability.

Materials and Methods

The research work "Combining ability analysis in linseed

Results and Discussion

Lines from the parents as a good general combiner, IC-0498589 exhibits good GCA effect for plant height, technical height, and stem diameter. Among testers, RLC-92 exhibits good GCA effect for technical height (cm), seed yield/plant (g), and seed yield/plot (g), while RLC-133 and RLC-153 exhibit good GCA effect for harvest index (%), number of seeds/capsule, and 1000 seed weight (g). RLC-148 displays good general combiners for the number of primary and secondary branches per plant as well as the percentage of oil content. As a result, their parents are regarded as effective general combiners for these characteristics.

The cross combinations IC-0076542×RLC-92 for days to 50% flowering, plant height (cm), no of Primary branches/plant, stem diameter (mm) shows good SCA effect followed by IC-0564654×RLC-133 for days to maturity, plant height (cm), no of primary branches/plant, no of seeds/capsule, stem diameter (mm) and IC-0564661×RLC-148 for days to maturity, no of secondary branches/plant, harvest index (%), seed yield/plant (g), sield yield/plot (g).

Conclusion

Line x Tester mating design is an extension (modified version) of top cross method in which several testers are used. The line × tester analysis is a common approach for assessing the expression of genetic aspects of traits (Kempthorne, 1957) [6] , which provides information about GCA and SCA of parents and at the same time it is helpful in identifying best heterotic crosses. Also, line × tester analysis provides information regarding genetic mechanism controlling yield and yield components. It is one of the most powerful tools for predicting the general combining ability (GCA) of parents and selection of suitable parents and crosses with high specific combining ability (SCA). The general (GCA) and specific (SCA) combining ability had a significant impact on evaluation of genotypes and population improvement. The GCA is the average performance of a genotype in hybrid combinations with number of genotypes. The SCA is the average performance of a specific cross combination expressed as deviation from the population mean. Combining abilities estimation can be used to determine the usefulness of the parents in hybrid combinations and to develop best hybrid adaptable to the different environments (Sprague and Tatum, 1942) [12] .

References

1. Biradar SA, Ajithkumar K, Rajanna B, Savitha AS, Shubha GV, et al. Prospects and challenges in linseed (Linum usitatissimum L.) production: A review. Journal of Oilseeds Research. 2016;33(1):1-13.
2. Falconer DS. Introduction to quantitative genetics. 2nd ed. London: Longman Group Ltd.; 1981. p. 1-133.
3. Falconer DS. Introduction to quantitative genetics. New York: The Ronald Press Company; 1967. p. 1-135.
4. Ganorkar PM, Jain RK. Flaxseed-A nutritional punch. International Food Research Journal. 2013;20(2):519525.
5. Griffing B. Concept of general and specific combining ability in relation to diallel crossing systems. Australian Journal of Biological Sciences. 1956;9(4):463-493.
6. Kempthorne O. Introduction to genetic statistics. New York: John Wiley and Sons Inc.; 1957. p. 1-545.
7. Muir AD, Westcott ND. Flax-The genus Linum. London: Taylor & Francis; 2003. p. 1-340.
8. Newkirk R. Flax feed industry guide. Winnipeg, Manitoba: Flax Canada 2015; 2008. 24 p.
9. Nirala R, Rani N, Acharya S, Vishwakarma R, Ranjan T, Prasad BD, Pal AK. Combining ability analysis for grain yield and its component traits in linseed (Linum usitatissimum L.). International Current Journal of Applied Science. 2018;31(4):1-12.
10. Nôžková J, Pavelek M, Bjelková M, Brutch N, Tejklová E, et al. Descriptor list for flax (Linum usitatissimum L.). Nitra, Slovakia: Slovak University of Agriculture in Nitra; 2016. p. 1-102. doi:10.15414/2016.9788055214849.
11. Przybylski R. Flax oil and high linolenic oils. In: Bailey's Industrial Oil and Fat Products. 6th ed. New York: John Wiley & Sons Inc.; 2005. p. 357-380.
12. Sprague GF, Tatum LA. General vs. specific combining ability in single crosses of corn. Journal of the American Society of Agronomy. 1942;34(10):923-932.
13. Thakur K, Sao A, Gauraha D, Nair S, Tandekar K. Estimation of combining ability using line × tester analysis for yield and its contributing traits in aromatic rice (Oryza sativa L.). Biological Forum-An International Journal. 2023;15(7):1-9.