~ 3033 ~ Journal of Pharmacognosy and Phytochemistry 2019; 8(4): 3033-3037 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2019; 8(4): 3033-3037 Received: 25-05-2019 Accepted: 27-06-2019 Aarti Sharma Department of Genetics and Plant Breeding, Narendra Deva University of Agriculture and Technology, Faizabad, Uttar Pradesh, India Satyendra Kumar Department of Genetics and Plant Breeding, Narendra Deva University of Agriculture and Technology, Faizabad, Uttar Pradesh, India MP Chauhan Department of Genetics and Plant Breeding, Narendra Deva University of Agriculture and Technology, Faizabad, Uttar Pradesh, India Correspondence Aarti Sharma Department of Genetics and Plant Breeding, Narendra Deva University of Agriculture and Technology, Faizabad, Uttar Pradesh, India Simple & joint scaling tests for yield and yield attributing traits in linseed ( Linum usitatissimum L.) Aarti Sharma, Satyendra Kumar and MP Chauhan Abstract Simple and joint scaling tests done on four crosses following generation mean analysis unveiled presence of epistatic interaction hence hints fitness of digenetic interaction model for all the eleven characters in the four crosses. Duplicate type of epistasis was detected for number of secondary branches per plant, number of capsules per plant, number of seeds per capsule, biological yield per plant, harvest index and 1000-seed weight in cross I; days to 50% flowering, days to maturity, number of capsules per plant, biological yield per plant, harvest index, 1000-seed weight and seed yield per plant in cross II; number of primary branches per plant, number of secondary branches per plant, number of capsules per plant, number of seeds per capsule, biological yield, harvest index, 1000-seed weight and seed yield per plant in cross III; days to maturity, plant height, number of secondary branches per plant, number of seeds per capsule, biological yield per plant and 1000-seed weight in cross IV. While complementary type of epistasis was observed for plant height and number of primary branches per plant in cross I; plant height, number of secondary branches per plant and number of seeds per capsule in cross II; days to maturity and plant height in cross III. Keywords: Simple scaling test, Joint scaling test, linseed Introduction Linseed (Linum usitassimum L.) belongs to the family Linaceae is an annual herbaceous plant. Linseed is grown either for fiber or oil. Linseed is not much in domestic use but it has substantial use in pharmaceutical, cosmetics and lubricant industries (Amit J. Jhala and Linda M. Hall, 2010). Thus versatile uses of linseed make it an important agro-industrial crop. In breeding programme, it is essential to have an idea of the nature and magnitude of genetic variability and to explore full range of variability in population for complex traits like yield, plant breeders favors the inter-mating approaches to elevate population mean and genetic variability. The simple scaling tests (Mather, 1949; Hayman and Mather, 1955) [5, 3] and joint scaling test (Cavalli, 1952) [2] followed by generation mean analysis (Jinks and Jones, 1958) [4] provide more precise assessment of variability by studying gene action and effects. Therefore study of simple and joint scaling tests were done for 11 metric traits of four crosses of linseed which directly or indirectly influences yield of linseed crop. Materials and Methods Simple and joint scaling tests were calculated for each of the six generations (P 1 , P 2 , F 1 , F 2 , BC 1 , BC 2 ,) of four cross families viz., Cross I, NDL- 2004-05 X GS-234, Cross II, NDL-2004- 05 X A-95 B, Cross III, NDL2004-05 X TL-27, Cross IV, NDL- 2004-05 X TL-11 by generation mean analysis. The experimental materials were evaluated during Rabi season of 2013-14 at the research farm of Narendra Deva University of Agriculture & Technology, Narendra Nagar (Kumarganj), Faizabad UP, in a compact family block design with three replications. The estimation of simple scaling tests were done by using Mather (1949), Hayman and Mather (1955) [5, 3] four scaling tests, namely, A, B, C, and D which are. The significant deviation of any one or more of these four scales from zero indicates presence of epistasis. Further, joint scaling test of Cavalli (1952) [2] gives more general, convenient adoptable and informative approach of any kind of generation used in estimation of the genetic parameters and to test goodness of fit. The analysis of variance for Compact Family Block Design (Panse, V. G. and P. V. Sukhatme, 1954) [7] for eleven characters of four crosses was done separately. Significance of data was tested by ‘F’ test. Experimental Results Cross I (NDL 2004-05 x GS-234) In cross I (Table 1) all the four scales (A, B, C and D) were found highly significant for all characters except for days to 50% flowering.