Pigeonpea (Cajanus cajan (L.) Millsp.) is an important leguminous short lived perennial cultivated as annual crop in semi-arid tropical and subtropical regions of the world. It is generally cultivated as a sole crop or as a mixed crop with short duration cereals or legumes as well as with other crops like cotton and groundnut. Across the globe, pigeonpea is cultivated on 4.86/million ha, with an annual production of 4.1 million tons and productivity of 844 kg/ha. India is the leading producer of pigeonpea in the world accounting for 4.09/million ha area, 3.27 million tons of production and productivity of 800 kg/ha (DCA 2011). Pigeonpea is a hardy and drought tolerant crop assuring sustainable returns from marginal lands with minimum input, hence it is considered as very suitable crop for sustainable agriculture. Pigeonpea seeds contain 20%~24% protein and reasonable amounts of essential amino acid making it an important source of dietary protein, mainly in vegetarian-based diets. The seed and pod husks make quality feed, whereas dry branches and stems serve as domestic fuel. Fallen leaves from the plant provide vital nutrient to the plant also enriches soil through symbiotic nitrogen fixation (Varsheny et al., 2010). India is the world largest pigeonpea producer accounting for 90 per cent of the world production (Ganapathy et al., 2009; 2010). New varieties have to be developed to attain high yield potential. For this, basic information on genetic variability and inheritance of yield and its component traits are essential to determine the most efficient breeding approaches (Saxena, 2008).

Results and Discussion
The analysis of variance (ANOVA) for 12 quantitative traits in F₃ generation revealed highly significant variation among 180 F₃ recombinant lines and check genotypes. Similarly, these recombinants and checks recorded highly significant variation in F₄ generation also for all the 12 quantitative traits (Table 1) studies viz., days to 50% flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, number of pods per plant, number of seeds per pod, number of seeds per plant, pod bearing length (cm), test weight (g), seed yield per plant (g), seed yield (Kg/ha). It was evident from the present investigation that highly significant genetic variation was observed among the pigeonpea recombinant lines in F₃ and F₄ generation with respect to days to 50 per cent flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, number of pod per plant, number of seed per pod, number of seeds per plant, pod bearing length (cm), test weight (g), seed yield per plant (g), seed yield (kg/ha).

Table 1 Mean sum of squares (ANOVA) for 12 quantitative traits in recombinant line of Gullya white×Maruti cross in F3 and F4 generation

The results of the variance component in this study indicated that the phenotypic coefficient of variation was higher than the genotypic coefficient of variation for all traits in both F₃ and F₄ generation. This result is in accord with reported by several authors (Damarany, 1994; Umaharan et al., 1997; Ubi et al., 2001; Omoigui et al., 2006) in cowpea. The magnitude difference in GCV and PCV were recorded higher in F₃ and F₄ generation (Figure 1; Table 2) for days to 50 per cent flowering, number secondary branches, number of seeds per pod, number of pods per plant, pod bearing length, seed yield per plant and seed yield (kg/ha). Similar observations were made by Ghodke et al (1994).

Figure 1 Phenotypic and genotypic coefficient of variance for 12 quantitative traits of Gulyal white×Maruti in F3 and F4 generation

Table 2 Genetic variability estimates for 12 quantitative traits in recombinant lines of F3 generation in Gulyal white x Maruti cross in pigeonpea

The minimum magnitude difference in GCV and PCV for all other traits like number of seeds per plant, pod bearing length and test weight (gm) were studied implied that the trait are mostly governed by genetic factors with little role of environment in the genetic expression of these characters. Thus the selection of these traits on of the basis of the phenotypic value may effective. W. Manggoel et al (2012) and Nausherwan et al (2008) reported that polygenic variation may be phenotypic, genotypic or environmental and the relative values of these three types of coefficient gives an idea about magnitude of variability.

The magnitude of broad sense heritability ranged from 54 per cent for days to maturity in F₃ and number of primary branches in F₄ to 93 per cent for days to 50 per cent flowering in both generations (Figure 2; Table 3). Similarly the higher magnitude of heritability was observed in seed yield per plant (gm) (83.69%), no of primary branches per plant (82.47%), no of pods per plant (80.48%), in F₃ and seed yield (kg/ha) (82.82%), no of pods per plant (82.62%), pod bearing length (cm) (81.72%), test weight(gm) (81.39%) in F_4. The broad sense heritability estimates in this study were generally high for all the traits in both generations. High heritability suggested the major role of genetic constitution in the expression of the character and such traits are considered to be dependence for genetic up gradation of pigeonpea. The high heritability recorded in this study were in agreements the values reported from several other worker in pigeonpea (Vange and Egbe Moses, 2009; Ghodke et al., 1994; Deshmukh et al., 2000; Basavarajaiah 2000; Satish Kumar et al., 2006; Firoz mahamad et al., 2006; D. Bhadru, 2011) According to Ubi et al (2001). Genetic advance over the mean were observed range from 8.89% (days to maturity) to 58.04% (No of seeds per pod in F₃) and from 9.86% (days to maturity) to 51.51% (Days to 50% flowering in F₄). High heritability coupled with genetic advance over mean in days to 50% flowering, no of primary branches, no of pod per plant, seed yield per plant (gm), seed yield (kg/ha) in both the generation. These findings are in agreement with the earlier reports of Panda and Singh (1997), Singh et al (1998) Dhall et al (2001) and Dhankar and Dhankar (2002). Heritability estimates along with genetic advance are more useful in predicting the resultant effect for the selection of the best individuals from a population. High broad sense heritability value coupled with genetic advance indicate the predominant additive gene action in the expression of these traits and thus they can be improved through individual plant selection (Johnson et al., 1955; Panse, 1957; Vange and Egbe Moses, 2009; Makeen et al., 2007; D. Bhadru, 2011).

Figure 2 Broad sense heritability estimated for 12 quantitative traits in recombinant lines of Gulyal white×Maruti F3 and F4 generation

 

Table 3 Genetic variability estimates for 12 quantitative traits in recombinant lines of F4 generation in Gulyal white×Maruti cross in pigeonpea