Adaptation of landrace and variety germplasm and selection strategies for lucerne in the Mediterranean basin
Adaptation of landrace and variety germplasm and selection strategies for lucerne in the Mediterranean basin
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DOI：
10.1016/j.fcr.2010.11.003
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发表时间：
2011-01-31
影响因子：
5.8
通讯作者：
Mezni, M.
中科院分区：
文献类型：
--
作者：
Annicchiarico, P.;Pecetti, L.;Mezni, M.
紫花苜蓿(Medicago Sativa L)可以提高西地中海盆地作物-畜牧系统的经济和环境可持续性，但由于灌溉水资源短缺和气候变化，需要更好地适应紧张的环境。本研究对来自摩洛哥、意大利和突尼斯的5个地方品种和来自法国、意大利、澳大利亚和美国的7个品种在阿尔及利亚、突尼斯、摩洛哥和意大利的10个农业环境中的3年干物质产量进行了评估，其中4个品种进行了雨水灌溉，1个品种进行了连续灌溉(绿洲管理)，5个品种进行了灌溉，但在夏季暂停灌溉9周。我们的目标是针对特定环境的品种，并协助区域育种计划制定适应战略、遗传资源和国际合作机会。作物在所有环境中都保持良好，但环境平均产量与年和春夏(4-9月)可用水严格相关(P<；0.01)。与灌溉相比，雨养作物的产量降低了42%，春夏可用水减少了61%，这三个地点在两种管理方式下都保留了夏季水。所有这些站点都显示出基因x管理交互作用(至少P<；0.10)。在10个环境中，高产品种间存在着基因×环境(GE)互作效应。在因子回归模型中，总收获量(范围：9-23)、土壤盐分(范围：0.20-6.0dsm(-1))和春夏平均有效水量(范围：102-932 mm)被选为显著的(P<；0.05)环境协变量，可解释Ge交互作用变化的53%。这个模型被用来作为这些因子特定地点水平的函数来定位品种。其结果与具有两个GE互作主成分的加性主效应和乘性互作模型基本一致。意大利的一个地方品种表现出对严重干旱易发环境的特殊适应，而来自北非的地方品种则不适应这种环境。摩洛哥的一个地方品种专门适应了高收成(部分原因是频繁割草)。一个耐盐性品种和一个摩洛哥地方品种专门适应了盐胁迫环境。作为GE互作效应函数的环境分类表明，有三类可能是特定繁殖的对象：(I)春夏可用水有限的雨养或灌溉环境(
Lucerne (Medicago sativa L) can enhance the economic and environmental sustainability of crop-livestock systems in the western Mediterranean basin, but requires improved adaptation to stressful environments because of a predicted shortage of irrigation water and climate change. This study reports on three-year dry matter yields of five landraces from Morocco, Italy and Tunisia and seven varieties from France, Italy, Australia and USA assessed across 10 agricultural environments of Algeria, Tunisia, Morocco and Italy of which four were rainfed, one was continuously irrigated (oasis management), and five were irrigated but adopted a nine-week suspension of irrigation during summer. Our objectives were targeting cultivars to specific environments, and assisting regional breeding programmes in defining adaptation strategies, genetic resources and opportunities for international co-operation. The crop persisted well in all environments, but environment mean yield was strictly associated (P < 0.01) with annual and spring-summer (April-September) water available. Rainfed cropping implied 42% lower yield with 61% less spring-summer water available relative to irrigation with withheld summer water across three sites hosting both managements. All of these sites showed genotype x management interaction (at least P < 0.10). Cross-over genotype x environment (GE) interaction between top-yielding cultivars occurred across the 10 environments. Total number of harvests (range: 9-23), soil salinity as measured by electrical conductivity (range: 0.20-6.0 dS m(-1)), and average spring-summer water available (range: 102-932 mm) were selected as significant (P < 0.05) environmental covariates in a factorial regression model explaining 53% of GE interaction variation. This model was exploited for targeting cultivars as a function of site-specific levels of these factors. Its indications agreed largely with those of an additive main effects and multiplicative interaction model with two GE interaction principal components. An Italian landrace exhibited specific adaptation to severely drought-prone environments, whereas landraces from north Africa were not adapted to such environments. One Moroccan landrace was specifically adapted to high number of harvests (partly reflecting frequent mowing). One variety selected for salt tolerance, and one Moroccan landrace, were specifically adapted to salt-stress environments. Environment classification as a function of GE interaction effects indicated three groups which may be object of specific breeding: (i) rainfed or irrigated environments featuring limited spring-summer water available (