Interactions between fruiting perianth and various abiotic factors differentially affect seed germination of Salsola brachiata

Many structural features of seeds such as fruiting perianth and various abiotic factors can influence seed germination characteristics. However, thorough studies on the interactions of fruiting perianth with different abiotic factors are relatively scarce. The aim of this study was to assess the effects of fruiting perianth, abiotic factors (temperature, light, NaCl and PEG) and their interactions on germination characteristics of a desert annual species, Salsola brachiata. Results showed that fruiting perianth significantly inhibited seed germination. However, temperature regimes did not significantly affect germination percentage of naked seeds. Low and high temperatures (5/15 and 20/35 °C) aggravated the inhibition effect of fruiting perianth on germination percentage. Naked seeds germinated equally well in light and dark. Winged seeds had significantly higher germination percentage in light than those in dark. Overall interaction of fruiting perianth, temperature and light caused a significant reduction in seed germination at low or high temperatures and in dark compared with germination at medium temperature (5/20 – 10/25 °C) in light. Germination percentage and total germination of winged seeds or naked seeds decreased with the increase of NaCl or PEG concentration. The presence of fruiting perianth aggravated the inhibition effect of NaCl or PEG on seed germination. These results indicate that fruiting perianth of S. brachiata not only inhibits seed germination, but also has complex interactions with different abiotic factors.