Int.J.Curr.Microbiol.App.Sci (2018) 7(3): 198-211 198 Original Research Article https://doi.org/10.20546/ijcmas.2018.703.024 Cause and Effect Relationship in Yield and Its Attributing Traits in Early Segregating Generations of Mustard Crosses under Terai Agro-Climatic Zone of West Bengal, India Suvendu Kumar Roy 1* , Lakshmi Hijam 1 , Moumita Chakraborty 1 , Nagnathwar Vishal Ashokappa 1 , Sanghamitra Rout 1 , Vinod Ashok Kale 1 , Bijaya Sur 1 , Bilin Maying 1 , Aparajita Das 1 , Abhijit Kundu 2 , Rupsanatan Mandal 3 and Hossain Ali Mondal 3 1 Department of Genetics and Plant Breeding, Faculty of Agriculture, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India 2 All India Network Project on Jute and Allied Fibres, Directorate of Research, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India 3 Regional Research Station (Terai Zone), Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India *Corresponding author ABSTRACT Introduction Rapeseed-mustard contributes 27 % of the total oilseed production in India accounting for about 14% of world production and 22.5% of world area under rapeseed mustard. The genus Brassica comprises of six species (B. campestris, B. oleraceae, B. juncea, B. nigra, International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 03 (2018) Journal homepage: http://www.ijcmas.com In F 3 population except seeds per siliqua and 100 seed weight the 15 crosses differed significantly for all the other nine characters, however in F 4 population the 15 crosses differed significantly for all the characters. Pusa Bahar × Rajasthan local selection -1 (13.62) was the highest performer in F 3 generation and in F 4 Rajasthan local selection1 × Pusa Barani (12.53) was the highest yielder. High h 2 and GA were found for height upto first fruiting branch and seed yield per plant in both F 3 and F 4 and GA were found for height upto first fruiting branch and seed yield per plant in both F 3 and F 4 generations. At genotypic level seed yield per plant was positively associated with the plant height, days to physiological maturity, secondary branches per plant and 100 seed weight in F 3 generation and primary branches per plant in F 4 generation. At phenotypic level, seed yield per plant was positively associated with plant height, days to physiological maturity and secondary branches per plant and positive association and high direct effect on seed yield per plant was exhibited by plant height and secondary branches per plant in F 3 generation and in F 4 generation primary branches per plant was positively associated with seed yield per plant although it had negative direct effect on seed yield, due to its better performance through days to physiological maturity, secondary branches per plant and total chlorophyll content and indirect selection for seed yield improvement in F 4 generation is possible for the present set of mustard crosses. Keywords Mustard, Correlation, Heritability, Path analysis, Direct effect, Indirect effect Accepted: 04 February 2018 Available Online: 10 March 2018 Article Info