Effects of Precipitation, Air Temperature and Drought on Calyx Lobe Number of Peganum nigellastrum Bge (Peganaceae Van Tieghem)

Abstract

Calyx lobe number on the fi rst fl owers of Peganum nigellastrum was 3-5 in the desert-steppe and 5 in the forest-steppe, but it decreased on the next fl owers down to 2 or completely disappeared in the desert-steppe, and up to 3-4 in the forest-steppe. The average of 4.4-7.6 mm of precipitation and 11-13 o C temperature of 10 days could be adequate for calyx maturity. Calyx could grow for at least 11 days after rainfall and decreasing mean of air temperature. The calyx on the fi rst fl owers rapidly grew, compared with that of the next fl owers. Maturity rate of calyx on the next fl owers was inhibited under drought. Calyx maturity on the fi rst fl owers may be completed, using an underground storage of previous year, but calyx on the next fl owers may be grown, using only photosynthetic production. Dryness that continued up to 11 days can call increased calyx lobe number of P. nigellastrum , and dryness that continues for longer than 11 days calls the decreased calyx lobe number.

Keywords

• Peganum nigellastrum
• calyx lobe number
• dryness
• precipitation