Treatments for Improving Seed Germination in Eggplant and Related Species

Orthodox seeds may present ditTerences in germination due to severa] reasons. Poor seed germination Iimits the use of different species for culture or p]ant breeding. In this work, we tested treatments for improving germination in two cultivars of common eggplant (Solanum melongena) and in six accessions of the related species S. macrocarpon, S. aethiopicum, and S. incanum. With the exception of S. incanum MM557, which did not germinate, seeds of the other accessions directly had lower final germination percentages when sown in Petri dishes with deep filter paper than those that were pretreated by surface sterilization and sown in nutrient medium; a further increase in the final germination percentages was achieved by addition of 1 mg LGA3 to the medium. The GA3-pretreatment not only increased the final germination percentages but promoted germination also by reducing germination time. Other treatments included stratification of S. macrocarp'on and S. aethiopicum seeds at 4°C for 15 or 30 days, as well as addition of 1 mg Lof TDZ and BAP for the BBS-168 accession, but this did not improve germination. The addition of 0.3 mg Lfluridone, an inhibitor of carotenoid biosynthesis, that is known to prevent ABA biosynthesis, increased the final germination percentages of S. melongena, S. aethiopicum and S. macrocarpon to a similar degree as GA3. Seeds of S. incanum MM-557 did not respond to this treatment but the hybrid derived from this S. incanum accession with eggplant accession ANS-26 showed high germination percentages (70%, 13 days after sowing) in NM medium with GA3, fluridone or both components. These results show that seed treatments can contrihute to improving germination of Solanum accessions with low