Contents lists available at ScienceDirect Scientia Horticulturae journal homepage: www.elsevier.com/locate/scihorti Heterosis breeding in chilli pepper by using cytoplasmic male sterile lines for high-yield production with special reference to seed and bioactive compound content under temperature stress regimes Om Prakash Meena a, *, Major Singh Dhaliwal b , Salesh Kumar Jindal a a Department of Vegetable Science, Punjab Agricultural University, Ludhiana 141 004, India b Directorate of Research, Punjab Agricultural University, Ludhiana 141 004, India ARTICLE INFO Keywords: Capsicum annuum Heterosis breeding Genotype × environment interaction Biochemical quality Temperature stress ABSTRACT The content of bioactive compounds and fruit yield in chilli is varying with the genetic and environmental factors. Increase the productivity of chilli pepper over the environments or under different temperature stress conditions, with enhance the bioactive compound contents in fruit for their industrial use in the International market, is a primary goal of plant breeder worldwide. To achieve this target, three newly developed cytoplasmic male sterile (CMS) lines and 20 potential restorer lines were crossed in a line × tester mating design to develop 60 F 1 hybrids. Eighty-five progenies including 60 F 1 hybrids, 23 parents and two commercial cultivars were evaluated for 15 plant growth, yield and quality traits with special focus on seed number and bioactive com- pounds, such as ascorbic acid, capsaicin content over three different temperature regimes, low temperature condition (the early season, E 1 ), normal temperature condition (the main season, E 2 ), and high temperature condition (the late season, E 3 ). Percent heterosis was estimated over better parent and two commercial checks. The mean squares (MS) due to genotypes, environments and G × E interaction were significant for all the traits, except for G × E interaction for 1000 seed weight. The maximum, the mean and the widest range of better parent heterosis was expressed for total yield plant -1 , which was mainly contributed by the number of fruits plant -1 . A wide range of variability for plant growth, fruit and quality traits offered opportunity to select hybrids for different seasons such as early (E 1 ), main (E 2 ) and late (E 3 ), and for varied purposes such as for fresh consumptions, powder making, and oleoresin and capsaicin extraction. In E 1 , the hybrids CMS463D13A × DL 161 and CMS463D13A × C 142, and in E 2 and E 3 , the hybrids CMS463D13A × SL 475 and CMS4626A × SL 475 have been identified as promising with higher yield, and for extraction of oleoresin and capsaicin. Overall, the hybrids CMS463D13A × SL 475, CMS463D13A × VR 523, CMS463D13A × YL 581 and CMS463D13A × IS 268 performed significantly better than the commercial checks for yield and quality traits, and thus have the potential to be exploited for commercial cultivation. 1. Introduction Chilli or hot pepper, a member of genus Capsicum in the family Solanaceae, is native to Central and South America (Pickersgill, 1991). The cultivated species of chilli include C. annuum L., C. chinense Jacq., C. frutescens L., C. baccatum L. Ruiz. & Pavon and C. pubescens Ruiz. & Pavon (Bosland, 1992). Of the five cultivated species C. annuum, that includes both the chilli pepper and the bell pepper, is the most widely cultivated. Chilli pepper is a source of various bioactive compounds, such as ascorbic acid, capsaicin content and those have great pharma- cological potential or health benefits (Montoya-Ballesteros et al., 2014). The fruits of chilli are consumed in various forms, such as fresh or cooked vegetables, processed into pickles or when dried as spice or condiment or powder making. Chilli is valued in the world market for its pungency, color and aroma (Zewdie et al., 2001). The pungency is caused by the presence of alkaloid compounds called capsaicinoids (Nelson and Dawson, 1923; Suzuki and Iwai, 1984). Till-date, more than 20 capsaicinoids has been reported in chilli (Bosland and Votava, 1999; Zewdie et al., 2001; Islam et al., 2015). Capsaicin, chemical trans-8-methyl-N-vanillyl-6-nonenamide, is a major alkaloid compound among the capsaicinoids. It represents ∼71 % of the total capsaicinoids and is characterized by acrid and sensation of heat (Othman et al., 2011). Capsaicin is widely used in the food, medicine, spice, pharma- ceutical and pesticide industries. Based on the clinical research, https://doi.org/10.1016/j.scienta.2019.109036 Received 28 April 2019; Received in revised form 6 October 2019; Accepted 13 November 2019 ⁎ Corresponding author. E-mail address: chandrawatop2-coavs@pau.edu (O.P. Meena). Scientia Horticulturae 262 (2020) 109036 Available online 30 November 2019 0304-4238/ © 2019 Elsevier B.V. All rights reserved. T