Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, Colorado, USA.
Department of Biology, Colorado State University, Fort Collins, Colorado, USA.
Physiol Plant. 2021 Aug;172(4):1941-1949. doi: 10.1111/ppl.13400. Epub 2021 Apr 7.
There is increasing interest in understanding how trait networks can be manipulated to improve the performance of crop species. Working towards this goal, we have identified key traits linking the acquisition of water, the transport of water to the sites of evaporation and photosynthesis, stomatal conductance, and growth across eight maize hybrid lines grown under well-watered and water-limiting conditions in Northern Colorado. Under well-watered conditions, hybrids with higher end-of-season growth and grain yield exhibited higher leaf-specific conductance, lower operating water potentials, higher rates of midday stomatal conductance, higher rates of net CO assimilation, and greater leaf osmotic adjustment. This trait network was similar under water-limited conditions with the notable exception that linkages between water transport, midday stomatal conductance, and growth were even stronger than under fully watered conditions. The maintenance of high leaf-specific conductance throughout the day was achieved via higher maximal conductance rates rather than lower susceptibility to conductance loss. Our results suggest that efforts to improve maize performance in well-watered and water-limiting conditions would benefit from considering the physiological trait networks governing water and carbon flux rather than focusing on single traits independently of one another.
人们越来越关注如何操纵性状网络以提高作物品种的性能。为此，我们在科罗拉多州北部的水培和限水条件下，对 8 个玉米杂交种进行了研究，鉴定出了连接水分获取、水分运输到蒸发和光合作用部位、气孔导度以及生长的关键性状。在水分充足的条件下，生长末期生长和籽粒产量较高的杂种表现出较高的叶片比导率、较低的操作水势、较高的中午气孔导度、较高的净 CO2 同化率和较大的叶片渗透调节。在限水条件下，该性状网络与完全水培条件下相似，但水运输、中午气孔导度和生长之间的联系甚至比水培条件下更强。全天保持较高的叶片比导率是通过较高的最大导度速率而不是较低的导度丧失敏感性来实现的。我们的研究结果表明，在水分充足和限制条件下提高玉米性能的努力将受益于考虑控制水和碳通量的生理性状网络，而不是独立于彼此的单个性状。
