The assessment of nature of gene effect for yield and its contributing traits and detection of epistasis in wheat was studied in five crosses involving seven parents through generation mean analysis. Scaling test and joint scaling test were showed significant for almost traits all crosses. Additive gene effects (d) were positively significant for days to maturity and tillers per plant in cross II; for seed per plant in cross IV. Dominance gene effects (h) were highly significant for days to 75% heading in cross II, III and IV; for days to maturity and grains per spike in cross II, for grain yield per plant and grains per spike in cross I. Additive x additive type of gene (i) were positive significant effect for days to 75% heading in cross II, III and IV; for days to maturity in cross II and grains per spike in crosses I, II; for 1000 grain weight in cross II and IV; for grain yield per plant in cross I. Additive x dominance type of gene effect (j) was positive significant for days to 75% heading in cross III; for days to maturity in cross II and III; for plant height in cross III; tillers per plant in cross II; for grain per spike and seed per plant in cross III and grain yield in cross IV. Dominance x dominance effect (l) were positively significant for days to 75% heading, plant height in cross I; for plant height in cross III, IV and V; for tillers per plant in cross II and for grains per spike in cross IV and V; seed per plant, grain yield in cross IV. Therefore, it has been suggested that selection of studied characters based on different gene action of generation mean to be used further crop improvement through ideal breeding programme.

Genetic analysis was carried out in 55 genotypes (10 parents and 45 F1s) through diallel mating design excluding reciprocals in bread wheat. Analysis of variance showed appreciable variability among the breeding material for almost all the traits under study. The highest value of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) was found for flag leaf area (PCV=18.82, GCV=17.74), biological yield (PCV=12.98, GCV=11.70), grain yield (PCV=11.90, GCV=10.39) and harvest index (PCV=10.39, GCV=10.05). Highest heritability with highest genetic advance was estimated for flag leaf area (h2=52.24, GA=34.64), biological yield (h2=15.04, GA=21.71), harvest index (h2=18.19, GA=20.01), peduncle length (h2=31.72, GA=15.96) and spikelets per spike (h2=34.92, GA=12.96), therefore selection will be effective based on these traits. Grain yield was found significantly correlated (at <1% level of significance) with productive tillers (gr=0.3283**, pr=0.4347**), spike length (gr=0.1959**, pr=0.2203**), spikelets per spike (gr=0.4342**, pr=0.3813**), grains per spike (gr=0.7188**, pr=0.4918**), biological yield (gr=0.6101**, pr=0.6616**), harvest index (gr=0.3518**, pr=0.3227**) and thousand grain weight (gr=0.5232**, pr=0.3673**). Similarly path coefficient analysis estimates for biological yield (g=1.0524, p=1.0554), harvesting index (g=0.8862, p=0.8291), thousand grain weight (g=0.0588, p=0.0269), grains per spike (g=0.0496, p=0.0074), spike length (g=0.0209, p=0.0289), days to maturity (g=0.0142, p=0.0127), productive tillers (g=0.0186, p=0.0147), peduncle length (g=0.0123, p=0.0157), days to 50% flowering (g=0.0093, p=0.0072) and plant height (g=0.0042, p=0.0020) showed high positive direct effects on grain yield indicating that due importance should be given to these traits during selection for high yield.

Genetic diversity is a useful parameter that facilitates production of more efficient plant species under different conditions. Accordingly, the most common bread wheat (Triticum aestivum L. emend, Fiori & Paol.) genotypes including 10 diverse parents with their F1s were grown in late sown condition and analyzed for genetic diversity and heritability. The high narrow sense heritability was observed for days to 75% flowering (45.63), days to maturity (37.55), chlorophyll fluorescence (Fv/Fm) (39.90) and protein content (31.52). The divergence analysis based on Euclidian methods indicated the presence of adequate genetic diversity in the experimental materials. The fifty five wheat genotypes were grouped into eight clusters. Cluster I had maximum (14) genotypes, while Cluster VI contained only one genotype. The maximum inter-cluster distance was observed among cluster VI and cluster VIII. The result of the principal components analysis revealed that six principal components (PC1 to PC6) accounted for nearly 81.75% of the total variation. The information so generated could be used to plan crosses and study the extent of heterosis.

The present investigation was conducted to magnitude of economic heterosis and inbreeding depression in F 2 s of bread wheat for identifying desirable cross combinations. The experimental materials comprised 100 genotypes which were consisted of 10 diallel parent and their F 1 s and F 2 s. The experimental material was conducted in randomized complete block deign with three replication at Economic Botanical Research Farm, Nawabganj of C.S. Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India 208 002. The analysis of variance revealed that the all components of variance had significant differences for almost the traits under studied over both generations. The result of economic heterosis revealed that the cross combinations, DBW 14 x K 0424, K 9162 x K 9423, K 9533 x K 0307, K 1114 x K 0424 and K 1114 x NW 2036 were good for grain yield per plant along with range of -88.54 (K 0424 x K 0911) to 28.52 per cent (DBW 14 x K 0424) and other traits compared to out of 45 F 1 s whereas, all these cross combinations also had significant grain yield demission in F 2 s results of increase of homozygosity among the crosses in advanced generations. The range of inbreeding depression varied from-50.36 (K 1114 x K 9423) to 49.12 % (K 0911 x K 0307) in F 2 s. Therefore, it could be concluded that these cross combination exploited in future breeding programme for development of good heterotic gene pool as well as evolution of wheat by improving of grain yield as well as others heat tolerance traits.

The present study was carried out to investigate the genetic variability and characters association for yield and its contributing traits in different wheat crosses namely, DBW14/HUW468 (I), DL788-2/PBW502 (II) and DBW14/HUW533 (III). The analysis of variance showed considerable amount of variation in all three crosses for different traits under study except someone indicates presence of sufficient variability in the material. Highest magnitudes of GCV, PCV and high heritability coupled with high genetic advance as percent of means were recorded for days to heading, days to maturity and 1000 grain weight in cross (I); for spike length and grain per spike in cross (II) for plant height and grain yield per plant in cross (III) indicated predominance of additive gene action in the inheritance of these traits. The correlation coefficients showed significant and desirable correlations for productive tillers and grains per spike in cross (I); days to maturity and grain weight per spike in cross (II) whereas days to heading, days to maturity, plant height, grain per spike, grain weight per spike, grains per spike and thousand grain weight in cross (III) at both genotypic as well as phenotypic level. Path analysis showed maximum positive direct effect on grain yield was exerted by days to maturity (2.205) followed by plant height (0.435), tillers per plant (2.091) and grain weight per spike (0.745) in cross (I). Grain weight per spike showed maximum positive direct effect on grain yield in cross (III) and cross (II) showed in 1000 grain weight, indicating the true relationship between these traits as good contributors to grain yield. As a result, these traits could be considered as important traits for selection in breeding programme for higher grain yield of the bread wheat.

The Department for International Development (DFID) Project carried out during 2002-03 to 2004-05 in the state of Haryana (India) aimed at increasing wheat productivity in a sustainable way, promoting resource conservation technologies (RCTs) for the north western India, increasing the profitability of farmers in rice wheat system and training the farmers on RCTs and seed production. This paper is based on the findings of base line survey, wheat crop evaluation by farmers before and at maturity, and survey of 100 farmers in the project area. The project successfully achieved higher varietal replacement. Area under PBW 343 declined and other varieties of similar potential were being adopted. PBW 502 was ranked first by the farmers followed by PBW 343, HD 2687, UP 2338, WH 711, PBW 373, UP 2425, RAJ 3765 and WH 542. The year wise correlation between ranking of varieties was highly significant which supported the farmers’ perception that the performance of the varieties was consistent over the years. Mean score of PBW 502 and PBW 343 showed superiority over other varieties. The farmers preferred PBW 502 for dense earhead, bold grain and more tillering. The farmers appreciated the concept of demonstration of all the improved varieties at one site.

Seedling mortality due to hybrid necrosis was observed in the cross PBW 443/HUW 533. Detailed information was generated by developing BC1, BC2 and F2 generations and evaluating them in the field along with parents and F1,s to examine the genetics of necrosis. The results revealed that this particular combination has varying degree of hybrid necrosis in F1, BC1 and F2 generations but the BC2 generation showed high degree of necrosis as all the plants died before the crown root initiation (CRI) stage. The present study suggests that some seeds may be obtained by crossing even the carrier of Ne1 and Ne2 genes through bridge crosses i.e. involving a third parent which carry inhibitor gene or a gene that modifies the complementary action of Ne1 and Ne2 genes.