~ 752 ~    Journal of Pharmacognosy and Phytochemistry 2017; 6(6): 752-755 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2017; 6(6): 752-755 Received: 29-09-2017 Accepted: 30-10-2017 Shanti Bhushan Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Sohan Ram Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Nutan Verma Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Tajwar Izhar Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Vinay Kumar Choudhary Tirhut College of Agriculture (Dr. RPCAU), Pusa, Samastipur, Bihar, India Anuj Kumar Choudhary Department of Plant Breeding and Genetics, BPSCA, Purnia, Bihar, India Sanjay Kumar Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Shipra Shalin Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Yachna Shree Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Anita Pande College of Biotechnology, BAU, Kanke, Ranchi, Jharkhand, India Manigopa Chakraborty Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Correspondence Shanti Bhushan Department of Plant Breeding and Genetics, BAU, Kanke, Ranchi, Jharkhand, India Genetic variability studies in F2 and F3 segregating generations for yield and its components in linseed (Linum usitatissimum L.) Shanti Bhushan, Sohan Ram, Nutan Verma, Tajwar Izhar, Vinay Kumar Choudhary, Anuj Kumar Choudhary, Sanjay Kumar, Shipra Shalini, Yachna Shree, Anita Pande and Manigopa Chakraborty Abstract The present investigation was carried out during 2015-16 and 2016-17 using the experimental material consisting of parents Meera, T-397 and Sekhar and backcross progenies of (Meera X T-397) X Meera and (Sekhar X T-3397) X Sekhar. For both the crosses, F2 and F3 populations were grown in the rabi 2015-16 and 2016-17 respectively. An estimate of GCV and PCV for all characters studied revealed that the phenotypic coefficient of variation (PCV) was higher than their corresponding genotypic coefficient of variation (GCV). In F2 generation of cross (Meera X T-397) X Meera, high heritability coupled with high genetic advance as percent of mean was observed for yield per plant, primary branches per plant, capsules per plant and 1000-seed weight. In F3 generation, high heritability coupled with high genetic advance as percent of mean was observed for capsules per plant and yield per plant. In F2 generation of cross (Sekhar X T-397) X Sekhar, high heritability coupled with high genetic advance as percent of mean was observed for yield per plant, capsules per plant, primary branches per plant and 1000-seed weight whereas in F3 generation, only two characters, namely, yield per plant and capsules per plant showed high heritability coupled with high genetic advance as percent of mean. The traits with high heritability and high genetic advance as percent of mean may be subjected to mass or progeny or family selection or any selection scheme, aimed at exploiting additive (fixable) genetic variance, a widely adapted genotype can be developed, possessing good quality and high productivity. Keywords: Genetic advance, Heritability, Linseed, Segregating generations Introduction Linseed or flax (Linum usitatissimum L.) is one of the oldest crops cultivated by man. It is important crop of tropical as well as temperate zone of the world. Based on diversity of plant types, linseed has two centers of origin i.e., South West Asia and the Mediterranean region of Europe (Darlington, 1963) [1] . It has a significant position with about 32 per cent share in total technical oil pool which is having industrial importance. The oil cake is a most valuable feeding cake to both milch and flattering animals. The cake is also used as manure and is a very good source of nitrogen to soil. Fibres obtained from the stem are known for their length, strength and beauty. They are spun into linen yarns which are used in making the best quality textiles. They are also used for the manufacture of rough textiles such as blankets, carpets, galicha, mattresses, etc. The remaining materials after fibre extraction can successfully be utilized as pulp for manufacturing straw boards, writing papers and parchment paper. The stalks are used as fuel. Crop improvement depends on the magnitude of genetic variability and extent to which the desired characters are heritable. This has in turn attracted the attention of biometrician to study the genetic aspects of economically important characters, such as yield, its components. Segregating populations are more important for improving plant types by operating further selection improvement. The present study was formulated to quantify the extent of genetic variation available for yield and yield components in the segregating generations (F2’s and F3’s of two crosses) of linseed and to assess the genetic gain that can be made by selection. To achieve this goal, the breeder has the option of selecting desirable genotypes in early generations or delaying intense selection until advanced generations, when progenies are nearly homozygous. In early stages of breeding programs, direct estimates of yield are quite difficult. Materials and methods The present investigation was carried out during 2015-16 and 2016-17 using the experimental