Elucidation the association between yield and agronomic traits in popcorn

Introduction

Maize is an annual, monoecious, cross-pollinated plant with a native range of Mexico and Central Africa. It was domesticated from a wild maize ancestor (Teosinte) and is referred to as the "queen of cereals" due to its vast genetic base and high yield potential. It is a C4 plant, a short-duration crop that demands three times more water compared to other crops. It is considered a "climate-resilient crop" as well as a "future crop" because of its high grain yield, productivity, greater adaptability to various environmental stresses, soil moisture regime and revenue for farmers. Presently, 193.7 million ha of land are used to grow approximately 1147.7 million MT of corn, with an average productivity of 5.75 t/ha across 170 countries. Globally, total consumption of corn viz. animal feed (61%), grain (17%) and other industrial uses (22%). It has become a global industrial crop, with 83% of the world's production going to the feed, grain, starch and bio-fuel industries. Corn is one of the world's most adaptable crops, with two main kinds, viz; field corn and specialty corn. Field corn is classified based on underlying consumer priorities, such as quality protein maize (nutritional security), waxy maize (paper industry), high-oil and others. Specialty corn sorted based on special uses, such as sweet corn, baby corn and popcorn, offers corn growers better economic opportunities. It has multiple uses, viz; grain, fodder, poultry, livestock and industrial products such as starch, oil, pharmaceuticals, paper, film, biofuel, tyres, alcoholic beverages, sweeteners, cosmetics, packaging, cornmeal, grits, starch, flour, tortillas and snacks. Popcorn is an extremely unique form of flint corn with a very hard endosperm and a low portion of soft starch and is characterised by its popping ability on heating the kernel, which is a unique quality of the endosperm. Popcorn swells and puffs up when heated and is a popular recreational snack with a high nutritional content. It is an excellent source of carbohydrates, energy, fibrous and a globally popular snack. It is a healthy, enjoyable food that assists digestion by supplying essential roughage. Indian popcorn cultivars have a lower popping ratio as compared to European and American cultivars. The high demand for popcorn has spurred research to discover traits that dictate its idiosyncratic popping ability and many attempts have been made to develop a popcorn industry, but it has been a hurdle because of the absence of stable and optimal hybrids with high popping volume and efficiency and also a lack of superior popcorn germplasm for popping characteristics, popping volume, flake size, and high-yielding genotypes. Popcorn germplasm has a narrow genetic background because most of the popcorn lines are descended from flint germplasm. However, it has relatively poor agronomic, yield, and popping performance and also more susceptible and prone to disease and pests.

Materials and Methods

The experimental material was comprised of the available 26 popcorn inbred lines as listed in (Table 1) from the ICAR-AICRP on Maize at the Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, B.H.U., obtained from various sources. During rabi 2016-17, the inbred lines were planted in a completely randomised block design with three replications with each entry planted in a single row plot of 4m length, with interrow spacing of 60 cm and plant to plant spacing of 25 cm maintained in each season during rabi, 2017-18, kharif, 2018 and rabi, 2018-19. The two seeds were planted per hill and after three weeks, thinning was conducted in each row to maintain the plant population at an optimal level. All agronomic practises were carried out in accordance with the maize crop.

Result and Discussion

The present experiment, The phenotypic twenty different observations were record based on underlying agromorphological and phenological, yield and popping quality traits. Estimation of genetic and phenotypic correlations among characters is useful in planning and evaluating breeding programme as it gains knowledge of interconnection among the traits. Plant breeders generally emphasis on genotypic correlation rather than phenotypic correlation as later is values recorded is result of sum of genetic and environmental causes, whereas genotypic correlation coefficient is the only heritable portion of total correlation coefficient. Yield is a complex trait associated with a number of different quantitative characters and is the prime concern of the plant breeder. Hence, all the changes in yield must be accompanied by changes in one or more character.

In parents phenotypic and genotypic character association were studied for twenty different qualitative and quantitative traits. Number of primary branches per tassel recorded positively significant correlation with plant height, whereas days to 50%

anthesis showed positively significant correlation with days to 50% silking and day's to75% maturity. Ear length and Ear diameter recorded positively significant correlation with number of kernels per row. Number of kernel rows per ear and number of kernels per row showed significant positive correlation with yield per plant at genotypic level. In hybrids phenotypic and genotypic character association were studied for twenty different qualitative and quantitative traits (Table 1 and2 [1] reported that middle sized kernels had the highest expansion volume. But, large sized kernels generally give lower popping volume than small kernels, because they contain a high percentage of soft endosperm (Pajic and Babic, 1991) [9] . Dofing et al. (1990) and Gökmen (2004) reported that large kernel samples had large flake size than small kernel samples, and higher expansion. The inconsistency in the relationship of 100kernel weight with popping expansion could possibly describe to variations in kernel size (Souza Júnior et al., 1985) and the environmental effects (Li et al., 2003) and popping methods (Dofing et al., 1990). Correlation between popping expansion and single plant yield was nonsignificant. This is accordance with the findings of Dofing et al.

Conclusion

This analysis highlights key associations that influence plant performance and yield, providing valuable insights for popcorn breeding and selection programs.

Acknowledgement

AcknowledgmentsI would like to express my sincere gratitude to Late Prof. J,P. Shahi and Prof. B.Sinha, All Professor and co-workers, whose guidance, insightful feedback, and encouragement were instrumental in the development of this research. I am also deeply grateful to Department of genetics and Plant breeding, Institute of agricultural science, Banaras Hindu University for providing the necessary facilities, resources, and support throughout the study.

References

1. Allred-Coyle TA, Toma RB, Reiboldt W, Thakur M. Effects of moisture content, hybrid variety, kernel size, and microwave wattage on the expansion volume of microwave popcorn. Int J Food Sci Nutr. 2002;51:389-94.
2. Ceylan M, Karababa E. Comparison of sensory properties of popcorn from various types and sizes of kernel. J Sci Food Agric. 2002;82(1):127-33.
3. Dewey DR, Lu KH. A correlation and path coefficient analysis of components of crested wheatgrass production. Agron J. 1959;51:515-18.
4. Dofing SM, Thomas-Compton MA, Buck JS. Genotype x popping method interaction for expansion volume in popcorn. Crop Sci. 1990;30:62-5.
5. Dofing SM, D′Croz-Mason N, Thomas-Compton MA. Inheritance of expansion volume and yield in two popcorn x dent corn crosses. Crop Sci. 1991;31:715-18.
6. Mora F, Scapim CA. Predicting breeding values of population effects of maize evaluated in Brazil and Paraguay. Agric Tec (Chile). 2007;67(2):139-46.
7. Gökmen S. Effects of moisture content and popping characteristics of popcorn. J Food Eng. 2004;65:357-62.
8. Li YL, Wu SW, Niu SZ, Li ZQ. Analysis of combining ability of popcorn with normal corn inbreds belonging to different heterotic groups. J Henan Agric Univ. 2003;37:15. (In Chinese).
9. Pajic Z, Babic M. Interrelation of popping volume and some agronomic characteristics in popcorn hybrids. Genetica. 1991;2:137-44.
10. Panse VG, Sukhatme PV. Statistical Methods for Agricultural Research Workers. New Delhi: ICAR; 1964. p. 381.
11. Sawazaki E. Parâmetros genéticos em milho-pipoca [PhD dissertation]. Piracicaba: Escola Superior de Agricultura "Luiz de Queiroz," USP; 1996.
12. Sharma RK, Kumar S. Association analysis for grain yield and some quantitative traits in popcorn. Crop Improv. 1987;14(2):201-4.
13. Hammer K, Filatenko AA, Korzun VK. Microsatellite markers: A new tool for distinguishing diploid wheat species. Genet Resour Crop Evol. 2000;47:497-505.
14. Russell JR, Fuller JD, Macaulay M, Hatz BG, Jahoor A, Powell W, Waugh R. Direct comparison of levels of genetic variation among barley accessions detected by RFLPs, AFLPs, SSRs, and RAPDs. Theor Appl Genet. 2000;95:714-7.