In the present study, the effect of ascorbic acid (5 mM) on some physiological parameters and three hormones (auxin, abscisic acid, salicylic acid) was determined under heat stress (40 °C) in maize tolerant cv. (MAY 69) and sensitive cv. SHEMAL (SH) at 0 h, 4 h and 8 h. Heat stress reduced total chlorophyll content (CHL), relative water content (RWC) and stomatal conductance (gs) in SH but did not lead to changes in MAY 69 at 4 h and 8 h. However, pretreatment with ascorbic acid increased (CHL), (RWC) and (gs) in SH under heat stress while it reduced MDA content significantly in both cv. We also observed that heat stress led to a reduction in SA level but increased ABA and IAA levels in SH, whereas it increased SA and IAA levels but did not change ABA level in MAY 69 at 4 h. Furthermore, in SH, ASC application under heat stress increased SA level and decreased IAA and ABA levels at 4 h, but it had no effect on SA and ABA at 8 h.

Conservation of orchids can be possible with effective seed germination and seedling growth methods. In this context, ex vitro symbiotic seed germination and seedling growth of orchid seeds may be convenient and advantageous. In this study, both the diversity of the root endophytic fungi in Serapias vomeracea (Burm.f.) Briq. and the ex vitro effects of these fungi on seed germination, seedling development and tuber formation were revealed. The fungi were isolated monthly for two years from S. vomeracea roots and the isolates were identified based on morphological characters and internal transcribed spacer (ITS) region of nuclear ribosomal DNA (rDNA) sequences. All of the Rhizoctonia-like isolates that joined the mycorrhizal association were closely related to Tulasnella calospora (thirty isolates). Non-Rhizoctonia isolates are closely related to Fusarium tricinctum (two isolates), Aspergillus spelaeus (one isolate) and Talaromyces pinophilus (Pezizales) (one isolate). The viability rate of the seeds was 90.32%. The seed packs were placed in soils containing fungus and the germination process was followed. All isolates associated with Tulasnella calospora promoted germination and seedling development. Isolate Svl 21 (Tulasnella sp.) was found to have the highest germination rate (98%) but isolate Svl 4 developed seedlings with advanced leaves (stage 4 (S4): seedlings with advanced leaves and/or rooted, 13.67%). All seedlings at S4 were transferred to the natural environment; the first tubers were observed seven months after. In this study, for the first time, a tuberous European orchid, S. vomeracea developed from seed to adult plant in a natural environment.

The orchids are in danger of extinction due to the destruction of their habitats and uncontrolled collection. The most effective way of protecting plants’ gene resources against these gradually increasing threats is seed banks. A viability test was conducted with two different scarification methods for Anacamptis laxiflora (Lam.) seeds preserved at 4 °C since 1988. The seeds were exposed to 5% Ca(ClO)₂ at different periods in the year they were collected (1988) and seed coats were scarified. They were washed with sterile water, incubated for 12 h in TZ in the dark at 28 °C. Seeds with red stained embryos were evaluated as viable. Since the highest live seed rate (62%) was obtained in 8 h of 5% Ca(ClO)₂ application, this period was applied in 20^th and 30^th years. In addition, in the 30^th year, the seeds were incubated in moisturized cocopeats for 5 days and then the viability test was conducted with TZ. The viability rate of embryo containing seeds was 81,63%. Seeds inoculated with Rhizoctonia solani AG A were germinated at a rate of 91.16%. Seed packages were buried in their habitats and it was found that the seeds died completely two years after they were buried.