INTRODUCTION TO GROUNDNUT IN RESPECT OF VARIABILITY AND GENETIC PARAMETER FOR QUALITY CHARACTER

                                                                                                               INTRODUCTION 

 

                Groundnut (Arachis hypogaea L.) is a self pollinated, allotetraploid (2n=4x=40) with a genome size of 2891 Mbp. Groundnut (Arachis hypogaea L.), a major oilseed crop that ranks 12th position among the food crops of the world. This annual legume is a native of South America (Brazil), but now grown throughout the tropical and warm
temperate regions of the globe between latitudes 400 N to 400 S.

              India is largest grower and second producer of groundnut after china. India produces 18.2% groundnut of total world production with the average productivity is about 0.98 tones/ha which is very much lower than the world average of 1.62 tones/ha. It accounts for around 25% of the total oilseed production of the country.  Globally, groundnut production and area during 2011–2012 averaged 6.93 million tones and 141.1 million hectares. (Ministry of agriculture, Govt. of India 2011) and production of oil seeds in India 30012.2 thousand tones. According to the annual report of 2012 [Directorate of Groundnut Research (DGR), Junagadh] Groundnut production of India during 2011 - 2012 was estimated as an average of 5.62 million tones produced in an area of 4.19 million hectares. The yield of groundnut during this year was estimated as an average of 1341 Kg. /ha. Oilseeds occupy a pride place in the Indian economy and groundnut is a kingpin among oilseeds grown in India. More than 80 per cent of groundnut production in the country is used for extraction of oil and about two per cent is exported for confectionary purposes. Currently, groundnut is grown on nearly 25.20 million hectares around the world with an annual production of 34.05 m tons of nuts-in-shell.

                 Groundnut contains on the average 12-15% carbohydrates, 25-30% protein and 45-50% oil. The nuts may be chewed uncooked, but are usually eaten boiled or roasted. The nuts can also be boiled, fried, ground into groundnut butter, or crushed for oil. Groundnut butter is extensively used in the preparation of soup and as bread spread (Tsigbey et al., 2004).

                Study of genetic variability reveals variation in different quantitative and quality parameter. Variation may be due to environmental factor, mutation agents or may be due to attack of any biological agents. Also genetic variability is essential and the basic requirement for crop improvement as it provides wider scope for selection for initiating an effective and successful breeding programmed and it became imperative to study the level of genetic variability available in the existing genotype. Thus, effectiveness of selection is dependent upon the nature, extent and magnitude of genetic variability present in material and the extent to which it is heritable.

                  Heritability in broad sense according to Lush (1949) is the ratio of total genotypic variance to phenotypic variance, expressed in percentage and it is the heritable portion to the phenotypic variance. Heritability plays an important role in deciding the stability and strategy for selection of a character Hanson (1963) stated that heritability and genetic advance are two complementary concepts. High heritability alone is not enough to make sufficient improvement through selection in advance generations unless accompanied by substantial amount of genetic advance. The heritability in combination with amount of variability present in the genotypes influences the gain to be obtained from selection. Character exhibiting high heritability may not be necessarily giving high genetic advance. High heritability should be accompanied by high genetic advance to arrive at more reliable conclusion Johnson et al., (1955).

                  One of the most profound multifaceted challenges facing humankind into the next millennium is the need to ensure not only adequate quantity but also of high quality food. This is rightly summed up by the German proverb, ‘A man is what he eats’. Oilseed production research has primarily emphasized on increased crop yields and higher oil contents. Until very recently, there has been little encouragement for research emphasis on improved oil quality by consumers and industries/traders.

                   There is an increasing need for high protein and low oil groundnut as these traits add to the confectionary quality of groundnuts. High oleate to linoleate (O/L) ratio has been associated with prolonged groundnut self life and decreased tendency toward rancidity (Braddock et al., 1995).

                  Study of calorimetry provides us reliable and authentic information about calories content which helps us to decide how much amount of groundnut will fulfil the calories requirement of our body.

                 Kernel yield is a very complex quantitative character and show polygenic inheritance means the character is controlled by many genes. Sometimes phenotypic character is influenced by environment than the genotypes. Qualitative character also keeps a much important place in any breeding programme. So to understand the variation produced by the genotypes and environment for yield and yield attributing character as well as qualitative character, the present investigation entitled “Study on genetic variability and estimation of calories in groundnut (Arachis hypogaea l.) genotypes” was undertaken with the following objectives:

1. To assess the genetic variability parameters for different quality characters in groundnut genotypes.

2.       Estimation of caloric values in different genotypes of groundnuts.