Twenty alfalfa cultivars were tested, under rainfed conditions in central Greece, for forage yield, agronomic and nutritive value in order to identify adaptive responses contributing to high resilience and productivity. From 2014 to 2017, five harvests (H1 to H5) per season were conducted. Two cultivars were also grown as irrigated checks. Annual and total dry matter (DMA and DMT) and harvest ratios (RH) were estimated. DMT was reduced by 42.9–48.1% under ambient rainfall compared to irrigated checks, which received 50.2% more water. The seasonal yield distribution demonstrated two contrasting strategies, however, equally effective for high resilience under rainfed conditions. The winter-active imported cultivars were the most resilient in the driest year, potentially due to their ability to exploit autumn rains, whereas the locally adapted genotypes were more productive in summer. The spring harvest ratio (RH1) was more indicative (r = 0.94, P < 0.01) of cultivar productivity, compared to plant survival (r = 0.65, P < 0.01), whereas the autumn harvest ratio (RH5) was representative of productivity under extreme drought (r = 0.53, P < 0.05). RH1 and RH5 were increased by 11.8 and 12.3%, respectively, whereas the summer ratios (RH3, RH4) were reduced by 47.3%, under rainfed v. irrigated conditions. Two Australian cultivars (‘Blue Ace’, ‘Icon’) achieved the highest RH5 suggesting an adaptive response by being more productive in autumn. However, the development of specifically adapted cultivars in terms of higher summer yield and plant survival may be necessary to cope with future climatic changes in the Mediterranean region.

中文翻译：

---

地中海雨养条件下苜蓿品种的评价

在希腊中部的雨养条件下，对 20 个苜蓿品种进行了草料产量、农艺和营养价值的测试，以确定有助于高恢复力和生产力的适应性反应。从 2014 年到 2017 年，五次收获（H1到 H5) 每季进行。还种植了两个品种作为灌溉检查。年和总干物质 (DM一种和DM吨) 和收获率 (RH) 估计。DM吨与灌溉检查相比，在环境降雨下减少了 42.9-48.1%，灌溉检查的水量增加了 50.2%。然而，季节性产量分布展示了两种截然不同的策略，它们对于雨养条件下的高恢复力同样有效。冬季活跃的进口品种在最干旱的一年中最具抵抗力，这可能是由于它们能够利用秋雨，而当地适应的基因型在夏季更具生产力。春收率（RH1) 更具指示性 (r =0.94,磷< 0.01) 的栽培品种生产力，与植物存活率相比 (r= 0.65，磷< 0.01), 而秋收率 (RH5) 代表极端干旱下的生产力 (r= 0.53,磷< 0.05)。RH1和RH5分别增加了 11.8% 和 12.3%，而夏季比率（RH3,RH4) 在雨养条件下减少了 47.3%五。灌溉条件。两个澳大利亚品种（“Blue Ace”、“Icon”）达到最高RH5建议通过在秋季提高生产力来做出适应性反应。然而，为了应对地中海地区未来的气候变化，可能需要开发具有更高夏季产量和植物存活率的特别适应性栽培品种。