Nutritional and chlorophyll fluorescence responses of lucerne (Medicago sativa) to waterlogging and subsequent recovery
Nutritional and chlorophyll fluorescence responses of lucerne (Medicago sativa) to waterlogging and subsequent recovery
复制标题
DOI：
10.1007/s11104-004-1082-x
复制
发表时间：
2005-03-01
期刊：
影响因子：
4.9
通讯作者：
Shabala, S
中科院分区：
文献类型：
--
作者：
Smethurst, CF;Garnett, T;Shabala, S
苜蓿（Medicago sativa， L）等多年生作物的周期性洪水是生产力下降的主要原因，在极端情况下导致植物死亡。本研究研究了涝渍及其后恢复对植物养分组成和PSII光化学的影响，以便更好地了解恢复与叶片光化学（叶绿素荧光）和养分动态有关的机制。3个苜蓿品种和1个育种品系在温室条件下淹水20 d，排干水分，再静置16 d恢复。涝渍苜蓿叶片和根系营养成分（P、K、Ca、Mg、B、Cu和Zn）显著低于自由排水对照，叶片N浓度也显著低于自由排水对照。同时，淹水植株根系中铁含量显著升高（5倍），叶片中钠含量显著升高（2倍）。因涝渍而受损的PSⅱ光化学在自由排水16 d后几乎完全恢复。在荧光恢复的同时，几种营养物质的浓度也在恢复的植物中增加。然而，生长参数在排水后仍然受到抑制。后者是由于以前淹水的植物的CO2同化能力较小（部分原因是营养缺乏和相关的PSII抑制），以及植物需要重新引导可用的营养和同化池来修复对光合机构和根系的损害。由此得出结论，对于任何苜蓿育种计划来说，重要的是不仅要确定对涝渍的耐受程度，还要确定不同基因型的恢复潜力，并在每个群体中寻找“优秀个体”。
Periodic flooding of perennial crops such as lucerne (Medicago sativa, L) is a major cause of lowered productivity and leads in extreme cases to plant death. In this study, effects of waterlogging and subsequent recovery on plant nutrient composition and PSII photochemistry were studied to gain a better understanding of the mechanisms of recovery as they relate to leaf photochemistry (chlorophyll fluorescence) and nutrient dynamics. Three lucerne cultivars and one breeding line were flooded for 20 d, drained and left to recover for another 16 d under glasshouse conditions. Leaf and root nutrient composition (P, K, Ca, Mg, B, Cu and Zn) of waterlogged lucerne was significantly lower than in freely drained controls, leaf N concentrations were also significantly lower in waterlogged lucerne. At the same time, there were significantly (5-fold) higher concentrations of Fe in waterlogged roots and Na in leaves (2-fold) of stressed plants. PS II photochemistry, which was impaired due to waterlogging, recovered almost fully after 16 d of free drainage in all genotypes. Alongside fluorescence recovery, concentrations of several nutrients also increased in recovered plants. Growth parameters, however, remained suppressed after draining. The latter was due to both the smaller capacity of CO2 assimilation in previously waterlogged plants (caused in part by nutrient deficiency and associated inhibition of PSII) and the plant's need to re-direct available nutrient and assimilate pools to repair the damage to the photosynthetic apparatus and roots. It is concluded, that for any lucerne-breeding program it is important to determine not only the degree of tolerance to waterlogging but also the potential for recovery of different genotypes, as well as look for 'outstanding individuals' within each population.