Selection for drought tolerance increases maize yields across a range of nitrogen levels
Selection for drought tolerance increases maize yields across a range of nitrogen levels
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DOI：
10.2135/cropsci1999.0011183x003900040012x
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发表时间：
1999-07-01
期刊：
影响因子：
2.3
通讯作者：
Lafitte, HR
中科院分区：
文献类型：
--
作者：
Bänziger, M;Edmeades, GO;Lafitte, HR
目前还不知道是否选择提高耐受性的特定非生物胁迫导致相关的变化，在其他压力下的表现。干旱和氮素缺乏是热带地区生产的重要限制因素。研究了耐旱性选择对热带玉米（Zea mays L.）在一定范围的N水平下。原始和先进的选择4个群体，改善耐中期干旱的2至8个轮回选择周期，在两个实验中进行了评估严重的N胁迫下，一个实验中N胁迫下，和两个施肥实验。在五个试验中，成熟期地上生物量中氮的积累平均为52 63、105、151和163 kg N ha（-1），获得的籽粒产量分别为3.0、2.9、5.2、6.0和6.5 Mg ha（-1）。选择对季中干旱胁迫的耐受性使谷物产量平均增加86 kg ha（-1）yr（-1），在严重的氮胁迫下（100 kg ha（-1）yr（-1）），产量增加不显著。耐旱选择提高了成熟期生物量和氮积累量，在严重氮胁迫下变化最大。此外，耐旱选择周期与叶片衰老延迟和氮收获指数增加或不变有关，这表明叶片氮被更有效地用于粮食生产。选择耐季中干旱胁迫似乎增加了粮食产量在一系列的N胁迫水平，并可能导致形态和生理的变化，特别是在N胁迫下的优势。
It is not known whether selection for improved tolerance to a specific abiotic stress leads to correlated changes in performance under other stresses. Drought and N deficiency are important constraints to production in the tropics. We examined the effect of selection for drought tolerance on performance of tropical maize (Zea mays L.) under a range of N levels. Original and advanced selections of four populations, improved for tolerance to midseason drought for two to eight recurrent selection cycles each, were evaluated in two experiments under severe N stress, one experiment under medium N stress, and two well-fertilized experiments. Nitrogen accumulated in the aboveground biomass at maturity averaged 52 63, 105, 151, and 163 kg N ha(-1) in the five experiments, and grain yields of 3.0, 2.9, 5.2, 6.0, and 6.5 Mg ha(-1) were obtained. Selection for tolerance to midseason drought stress increased grain yields by an average of 86 kg ha(-1) yr(-1) with nonsignificantly larger gains under severe N stress (100 kg ha(-1) yr(-1)). Drought-tolerant selections had increased biomass and N accumulation at maturity, the changes being largest under severe N stress. Additionally, drought-tolerant selection cycles were associated with delayed leaf senescence and an increased or unchanged N harvest index, indicating that leaf N was used more efficiently for grain production. Selection for tolerance to midseason drought stress appears to increase grain yield across a range of N stress levels and may lead to morphological and physiological changes that are of particular advantage under N stress.