Seed germination of two tomato cultivars following matriconditioning under optimal and stress temperatures

Seeds of two cultivars of Lycopersicon esculentum Mill.: New Yorker (NY) and Beta (BT), differing in vigor, were matriconditioned (MC) using Micro-Cel E. MC improved germination of seeds of both cultivars at optimal temperatures, a particularly strong improvement being seen at suboptimal temperature (10 degrees and 15 degrees C). At 10 degrees C, the matriconditioned NY and BT seeds reached T-50 15.1 and 7.16 days earlier, respectively, than unprimed seeds did. MC was able to alleviate thermoinhibition (35 degrees and 40 degrees C) in the BT seeds only. Matriconditioning improved seedling emergence both in the growth chamber and in the field, the effect being more distinct in BT than in NY. The fresh and dry weights of the seedlings obtained from matriconditioned seeds of both cultivars were higher than those of the unprimed seeds, but the MC effect was more pronounced in the BT seeds. The MC effect was higher when GA(4+7) was added during the treatment. The beneficial effect of MC alone or in combination with GA(4+7) on germination is partially (in NY) or almost completely (in BT) related to the significant increase in the activity of endo-beta-mannanase.