Mahmood et al.: Genetic potential and association among morpho-physiological traits of Petunia inbred lines - 7311 - APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 17(4): 7311-7332. http://www.aloki.hu ● ISSN 1589 1623 (Print) ● ISSN 1785 0037 (Online) DOI: http://dx.doi.org/10.15666/aeer/1704_73117332  2019, ALÖKI Kft., Budapest, Hungary GENETIC POTENTIAL AND ASSOCIATION AMONG MORPHO- PHYSIOLOGICAL TRAITS OF PETUNIA INBRED LINES MAHMOOD, A. 1 – ALI , Q. 2,6* – AHMAD, S. 1 – BAKHSH, A. 3 – MAHPARA, S. 3 – KAMARAN, S. 3 – MAMOON-UR-RASHID, M. 4 – SALMAN, S. 5 – WASEEM, M. 6 – HAIDER, M. S. 1 – NASIR, I. A. 7 1 Institute of Agricultural Sciences, University of the Punjab Lahore, Lahore, Pakistan 2 Institute of Molecular Biology and Biotechnology, University of Lahore, Lahore, Pakistan 3 Department of Plant Breeding and Genetics, Ghazi University, Dera Ghazi Khan, Pakistan 4 Department of Entomology, Faculty of Agriculture, Gomal University, Dera Ismail Khan, Pakistan 5 Department of Plant Breeding and Genetics, Gomal University, Dera Ismail Khan, Pakistan 6 Department of Agronomy, Faculty Agriculture, Lasbela University of Agriculture, Water and Marine Science, Uthal, Lasbela, Pakistan 7 Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Lahore, Pakistan *Corresponding author e-mail: saim1692@gmail.com (Received 7 th Feb 2019; accepted 8 th Apr 2019) Abstract. Petunia hybrida is considered as an important and beautiful ornamental flowering plant, grown throughout the world for its beauty and attractiveness. Various petunia hybrids have been produced by different countries. The present study was carried out to investigate the higher seed yield petunia line developed through selfing to produce F1 hybrids during the experimental seasons of the 2011-2014 period. The lines IAGS-P8, IAGS-P9 and IAGS-P11 performed well, both in the cluster analysis and minimum spanning tree, the inbred lines IAGS-P8 and IAGS-P9 showed to a higher similarity percentage. From statistical and regression analysis showed that stomata conductance, chlorophyll ‘a’ contents, chlorophyll ‘b’ contents, flowers per plant, flower fresh weight, seed area, seed weight and abscisic acid contributed higher to seed yield per plant in petunia. The higher abscisic acid concentration suggested that the petunia genotypes may be used to develop better seed yields and higher number of flowers per plant in petunia under environmental stress. This method proved to be more efficient as it reduced the cost, time and efficacy for better selection in petunia improvement program. Still, further studies are required which should cover different years and locations. Keywords: Petunia hybrida, abscisic acid, multivariate analysis, heritability, genetic advance Introduction Petunia hybrida is an important and the mostly used ornamental plant throughout the world from several years as commercially grown ornamental plant. Petunia hybrida is an important and mostly used genera to develop Petunia new varieties and hybrids. Griesbach (2007) has reported that Petunia has an old history in sense of development as an ornamental plant as compared with new emerging ornamental crops plant species. Ganga et al. (2011) suggested that the production of hybrid seed has been adapted by various ornamental crop plants breeding program to develop new colour and varieties of ornamental plants. It has been found that there are 20 South American origin species of