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

摘要

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 x 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 compounds, 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 x E interaction were significant for all the traits, except for G x 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 x DL 161 and CMS463D13A x C 142, and in Ey and E-3, the hybrids CMS463D13A x SL 475 and CMS4626A x SL 475 have been identified as promising with higher yield, and for extraction of oleoresin and capsaicin. Overall, the hybrids CMS463D13A x SL 475, CMS463D13A x VR 523, CMS463D13A x YL 581 and CMS463D13A x 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.