~ 1742 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(6): 1742-1745 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(6): 1742-1745 Received: 04-09-2018 Accepted: 06-10-2018 Vijay Sharma Banda University of Agriculture and Technology, Banda, Uttar Pradesh, India NS Dodiya Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India RB Dubey Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India SG Khandagale Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India Neelam Shekhawat ICAR-NBPGR Regional Station, Central Arid Zone Research Institute Campus, Jodhpur, Rajasthan, India Correspondence Vijay Sharma Banda University of Agriculture and Technology, Banda, Uttar Pradesh, India Estimation of heterosis for yield and some yield components in bread wheat Vijay Sharma, NS Dodiya, RB Dubey, SG Khandagale and Neelam Shekhawat Abstract The heterosis study for grain yield and its attributes was carried out in bread wheat [Triticum aestivum L. em. Thell] through half diallel mating design in four environments. The pooled analysis revealed significant differences between the environments for all the characters, indicating that environments had significant effect on the expression of different characters. The variance due to parents and F1 were also significant for all the characters studied demonstrating the presence of significant variability among the material used in the study and presence of average heterosis for all the characters. The magnitude of heterobeltiosis and standard heterosis altered for all the crosses and for all the characters studied. For the traits viz., flag leaf area, 1000 grain weight, grain yield per plant and number of grains per spike quite a large number of crosses manifested positive significant heterosis over the checks. In contrast to these, least heterotic effects were observed for days to heading and harvest index. The hybrids HI 1544 x HD 2987, Raj 4037 x HD 2987, PBW 175 x HD 2987, HD 2932 x Raj 4079 and PBW 175 x Lok 1 exhibited the highest, significant and positive heterotic effect and mean performance for grain yield per plant and some of its important component traits. This could be exploited commercially for heterosis breeding in wheat. Keywords: Heterosis, Genotypes, Grain yield, diallel, bread wheat Introduction Bread wheat (Triticum aestivum L. em. Thell) is an annual self-pollinated crop with chromosome number 2n = 6x = 42. Wheat is the staple food for over 27 per cent of global population in more than 40 countries. It is popularly known as ‘Stuff of life or King of the cereals’ because of the acreage occupied, high productivity and the prominent position it holds in the international food grain trade. The main wheat growing countries include China, India, USA, Russia, France, Canada, Turkey, Australia and Ukrain. In India, area and production of wheat during year 2014-15 was recorded 30.97 million ha and 88.94 million tonnes with an average productivity of 2872 kg ha -1 (DAC&FW, 2015). Wheat grain contains starch (60- 68%), protein (6-21%), fat (1.5-2.0%), cellulose (2.0-2.5%), minerals (1.8%) and vitamins. The uniqueness of wheat in contrast to other cereals is that wheat contains gluten protein which enables leavened dough to rise by forming minute gas cells and this property enables bakers to produce light breads. In a self-pollinated crop like wheat, the utilization of heterosis depends mainly upon the direction and magnitude of heterosis. Wheat breeders dealing with various aspects of hybrid wheat found that the economic heterosis for grain yield, on a large plot basis, ranged from 6 percentages (Borghi et al. 1986) [3] to as high as 41 percentages (Yadav and Murty 1976) [16] . The study was conducted for identifying the best cross combination(s) that could be used for commercial production of hybrid wheat as well as isolation of pure lines among the progenies of heterotic F1s for further amelioration of grain yield in wheat. Materials and Methods Experimental site and design Experimental material consisted of 8 diverse genotypes (Table 1) selected on the basis of broad range of genetic diversity for major yield components, geographical origin, heat tolerance and their suitability for different yield traits, were crossed in half diallel fashion resulting in 28 F1s at Research Farm, Rajasthan College of Agriculture, Udaipur (Rajasthan) during the year 2014-15. These eight parents and their 28 F1s and 2 checks viz., HI 1563 and HD 2967 were grown in a randomized block design with three replications under early (E1), normal (E2), late (E3) and very late (E4) sown conditions. The environments were created by four different date of sowings (Table 2). Row-to-row and plant-to-plant distances were 30cm