Effects of low pressure and hypoxia on growth and development of wheat

Wheat growing experiments were carried out in two low-pressure plant-cultivating facilities, to study the effects of low pressure (50.0 kPa) and hypoxia (10.4, 5.0 and 2.5 kPa) on the growth and development of wheat and get its cultivating techniques. Compared with ambient pressure, wheat average rates of photosynthesis and transpiration increased by 9.23% and 11.54%, respectively, after a 15 days' treatment at low pressure (50.0 kPa), and they increased continuously when oxygen partial pressure was reduced further. Shoot height decreased, and both tiller numbers of each plant and the proportion of roots in a whole plant increased. Harvest time was delayed under low pressure and hypoxia conditions, and the hypoxia effects on the results were greater than those of hypobaric conditions. The yields of wheat at 10.4 and 5.0 kPa oxygen partial pressure increased by 4.39% and 5.0%, respectively, but reproductive growth of wheat was inhibited seriously at 2.5 kPa oxygen partial pressure and there was almost no yield. Some contents of nutrients in seed enhanced, like nitrogen, protein, fat and so on, but others had no significant difference among four treatments. So the growth of wheat was promoted by low pressure (50.0 kPa) and hypoxia (10.4 and 5.0 kPa) in certain degree, but lower oxygen partial pressure (2.5 kPa) was unsuitable for reproductive growth of wheat.