Influence of Abiotic Stresses on Seed Germination, Quolity and..

Influence of Abiotic Stresses on Seed Germination, Quolity and Seed Production

Responses of 10 winter wheat cultivars (Astella, Estica, Ilona, Olga, Patru, Plodna, Samanta, Sárka, Vlada) to six different combinations of abiotic stresses were analysed in laboratory conditions and in pot experiments. Field experiments as control and suppletuentaty experiments are going on. Plant treatments during experiments were: standard level of nutrients (SN), low level of nutrients (LN), drought (D), drought + low pH (D+pH), high temperature + drought (HT+D), high temperature + drought + low pH (HT+D+pH). In investigated treatments existed the following order of morphological and yielding train decrease: HT+D+pI-I, HT+D, D+pH, D, LN, SN. The lowest reduction of 1000 gram weight was observed. Strong influence of stress conditions on gram quality (crude protein content, sedimentation test ...) was obtained. There was also measurable influence of abiotic stresses on a degree of contamination of seeds by spores of pathogenic fungi (preliminary results). Testing of seed vigor and biochemical analyssis of seeds of cultivars from different treatments is under preparation (October 1997). Seed provenance had vary strong effect on the first phase of plant development and also on yield formation (preliminary results).

Measurements of gross energy and net energy of seeds (J.g-1)from different stress treatments in analysed cultivars were made. The statistically significant differences existed only for cultivars, but for stress treatments were not statistically significant. There were not observed statistically significant results in case of analysis different nutrient level (nitrogen content) influence on gross and net energy.

A special attention was paid to the drought tolerance of seedlings. Osmotic adjustment in 5 days old dark grown seedlings was developed by water stress. The seeds of winter wheat cultivars, susceptible and tolerant to water stress were sorted on a net with 0.4 cm holes in two categories : large and small seed size. Water stress inhibits growth and decreases osmotic potential at the sama hydration level of seedlings. Osmotic adjustment of seedlings from larger seeds was about 0.03 MPa greater than in seedlings grown from small seeds and was greater 0.04 MPa in water stressed seedlings from larger seeds of drought tolerant wheat cultivars (for example Astella and Ilona). This mechanism was greatly influenced by seed size, especially in drought tolerant cultivars at early growing stage.

Authors: Ladislav Bláha, Vratislav Novák, Jiří Zámečník, František Hnilička, Iva Frančíková

Source: Cost 828, Workgroup 2, Meeting, Barcelona, Spain, November 10, 1997, p. 5