载人航天环境下开花前后光照强度对小麦生长发育及生产效率的影响

为了提高受控生态生保系统(CELSS)的能量利用效率,研究了在受控环境下开花前后光照强度对春小麦生长发育及生产效率的影响。结果表明,提高开花前光照强度(IBF)可显著缩短春小麦生育期;开花后光照强度(IAF)对小麦生育进程影响不显著。IBF的增强有利于春小麦营养体的构建,小麦籽粒产量有所提高,但小麦收获指数、粒叶比和能效比显著降低。IAF增强使小麦叶片光合速率、籽粒产量、收获指数、粒叶比和能效比均显著提高。高IBF下小麦籽粒产量的增加主要是因为提高了每株穗数和穗粒数,而高IAF下小麦籽粒产量的增加主要是因为提高了粒重。IBF和IAF提高均使得春小麦籽粒淀粉含量增加,蛋白质含量减少。高IBF对小麦产量的促进作用有限,而低IBF+高IAF的光照策略可以显著提高小麦的源库协调性和能量利用效率,可作为载人航天CELSS小麦培养的光照方案。

Effect of Light Intensity before and after Flowering on Wheat Growth,Development and Production Efficiency in Spaceflight Environment

In order to increase the enery using efficiency of controlled ecological life support system (CELSS).The effects of light intensity on production efficiency in different growth stages by using different light intensities before and after flowering were studied.As a result, the growing period of spring wheat was significantly shorten by elevated light intensity before flowering (IBF) while the growth period was not significantly affected by light intensity after flowering (IAF). Elevated IBF promoted the vegetative organ biomass and increased the grain yield of wheat.But the harvest index, grain leaf ratio and energy efficiency were significantly decreased. On the other hand, higher IAF mainly promoted the reproductive growth that Pn in postulation period was increased and more photosynthetic product was accumulated in grains. Biomass and grain yield significantly ascended with increased IAF, and the increase of grain yield was larger, so that the harvest index, grain leaf ratio and energy efficiency were significantly enhanced. In terms of yield components, elevated IBF enhanced grain yield mainly by increasing the spikes per plant and grains number per spike and IAF mainly by increasing the grain weight. Grain starch concentration was lifted and protein concentration was lowered by elevated light intensity both before and after flowering, and the increased starch concentration was helpful to the carbon hydrate supply for astronauts.The lighting strategy with low IBF and high IAF could significantly improve the source sink coordination and energy using efficiency of spring wheat in comparison with continuous high light intensity, and could be used in CELSS to save energy for manned spaceflight.