Estimates of heritability , genetic advance and correlation in F 3 populations of Wheat

Development of new high yielding wheat varieties is the main objectives of the wheat improvement programs. Knowledge about the genetic variability, heritability, genetic advance and correlation analysis for various parameters is indispensable to propose effective wheat breeding. This Research was carried out at Malakander research farm The University of Agriculture Peshawar, Pakistan during cropping season 2014-15. Nineteen wheat genotypes including 7 parents and their 12 F3 segregating populations of wheat were evaluated in a RCB design replicated trice. Analyzed data revealed significant genotypic variability among the genotypes for the studied parameters. The main purpose of the study was to estimate heritability, genetic advance and correlation. High heritability value was observed for grains per spike (0.95), grain yield plant (0.99), fertile tillers per plant (0.98), plant height (0.89), and leaf area (0.88). High genetic advance was observed for grain yield (14.16), flag leaf area (3.12) and grains per spike (2.49). Grains per spike and leaf area revealed significant and positive correlation with grain yield. Among the parents AUP (5008), JBZ and TATARA while, in segregating F3 wheat populations JBZ × WTN, JBZ × F. Sarhad, AUP (5008) × WTN were found better performing for yield and its contributing traits. Therefore these parental lines and F3 segregating populations could be used in future wheat improvement programs for economically important traits.


Introduction
Wheat (Triticum aestivum L.) is considered one of the most important and main cereal crop in world.It contains 20 percent calories and supply 36 percent food to accomplish basic food need of growing population.
Wheat was grown on area of about 9.03 million hectares and estimated yield of 25.286 m tonnes, while in Khyber Pakhtunkhwa wheat was cultivated on area of 0.68 m ha -1 with yield of 1.25 m tonnes [1].Pakistan is far below in the international ranking of wheat crop production it can be improved through the appropriate steps.There is dire need for valuable research to made better and high yielding genotypes and available to farmers.Heritability is an index for transmission of a character from one generation to next generation.The selection ability of wheat population mainly depends on the extent of heritable difference  F.Sarhad, Salim(2000) × WTN, TATARA × Barsat, TATARA × F.Sarhad, TATARA × WTN, AUP(5008) × Barsat, AUP(5008) × F.Sarhad, AUP(5008) × WTN were evaluated in a randomized complete block design (RCBD) with 3 replications.Each genotype was grown in 4 rows of 4 m length with row to row distance was kept 30 cm.Normal recommended cultural practices were followed throughout the growing session.

Statistical analysis
The collected data was statistically analysed by using Statistic 8.1 package and Least Significant Difference (LSD) test was determined for the comparison of means of wheat genotypes (Parent and their F3 segregating populations).Heritability Broad sense heritability was calculated (%) by the following formula explain by [6].

Genetic advance (GA)
Genetic advance (GA) was find out by mentioned formula described by [7].Genetic Advance = i ph 2 where, I is the selection intensity and its value is 1.75 at 10 p is the phenotypic std.deviation h 2 (B.S) = heritability broad based.

Results and discussion
Days to 50 % heading Days to heading of parents and F3 population are showed in (Figure 1).Parents JBZ, Sal-2000 and F3 wheat population Sal-2000 × F.Sarhad initiate heading earlier as compared to other genotypes.While parent F. Sarhad and F3 population TATARA × WTN were found late in heading.Low heritability for heading was observed (0.26) along with low genetic advance (1.35 days) (Table 1).Significant and positive correlation effect of heading with plant height were observed (r = 0.52) (Table 2).
[8] Reported also significant and positive correlation of heading with plant height and grains spike -1 in bread wheat.
[10] who also reported highly significant genetic variation among genotypes evaluated under normal irrigation.
Similarly, it has also been reported that plant height revealed significantly positive correlation with 1000 grains weight [11].

Flag leaf area
Genotypes had highly difference for flag leaf area the maximum flag leaf area was recorded by genotypes TATARA, while minimum was observed in salim (2000) × WTN (Figure 3).The results of our experiment are supported by khan et al.
[12] who reported the differences for flag leaf area among wheat genotypes.Low (0.07) to high (0.88) range of h 2 was observed for leaf area (Table 4).High broad sense heritability of 0.88 was showed by segregating population JBZ × Barsat, while low heritability of 0.07 was showed by JBZ × F.Sarhad.Similarly, selection response for flag leaf area ranged from 0.13 to 3.12 cm 2 (Table 3).Significant and positive correlation of leaf area with grain yield (r = 0.62) were observed however and non-significant with grains spike -1 (r = 0.36) (Table 2).Results were reported by [10], who also observed significant genetic variation between spring wheat genotypes.
[14] also elaborated the importance of correlation of flag leaf area with grains per spike -1 and kernel weight.× Barsat (23.9 g) (Figure 6).High heritability was observed in most of F3 wheat population except JBZ × Barsat and JBZ × F.Sarhad (Table 4).The genotypes TATARA × F.Sarhad was found best with highest heritability of 0.99 whereas, the F3 population JBZ × Barsat was found low heritability of 0.07).Genetic advance for grain yield ranged from 0.24 to 14.16 (Table 4).Likewise, grain yield revealed positive and significant correlation with grains per spike (r = 0.47) (Table 2).The current results are accordance with the results of

Figure 1 .
Figure 1.Days to 50% heading of parents and F3 populations of wheat genotypes

Figure 2 .
Figure 2. Plant height of parents and F3 populations of wheat genotypes

Figure 3 .
Figure 3. Flag leaf area of parents and F3 populations of wheat genotypes

Figure 5 .
Figure 5. Grains spike -1 of parents and F3 populations of wheat genotypes [17].The current results are supported by [18], [19] who reported positive correlation of yield and harvest index in bread wheat.

Figure 6 .
Figure 6.Grains yield plant -1 of parents and F3 populations of wheat genotypes