Morphological traits, nutritive values and physiological responses to two different water regimes of three Bituminaria bituminosa varieties: var. albomarginata, var. crassiuscula and var. bituminosa were evaluated in a greenhouse experiment. Two water regimes were imposed for 63 days; well-watered (WW) plants and deficit-watered (DW) plants, both starting from a high soil water content (dripping point). The three varieties showed similar aerial biomass reduction under reduced watering, 50% for var. albomarginata, 51% for var. bituminosa and 43% for var. crassiuscula. Var. Albomarginata showed lower shoot biomass under both water regimes than var. bituminosa (56.2% in WW plants and 55.2% in DW plants) and var. crassiuscula (52% in WW plants and 57.8% in DW plants). This lower shoot biomass could be attributed to the high initial soil water content imposed in this experiment, affecting early development. This hypothesis is supported by the lower root biomass production of var. albomarginata and its distribution. The DW treatment of this experiment was not sufficiently restrictive to cause morphological modifications, whilst of the forage quality variables analysed, only ash was affected. Var. crassiuscula and var. albomarginata had a lower specific leaf area (239 cm² g^-1 and 235 cm² g^-1, respectively) than var. bituminosa (352 cm² g^-1), which might represent an important adaptation to high light intensity and temperature conditions. The values of stem mass fraction (SMF) and leaf mass fraction (LMF) for var. crassiuscula (SMF = 0.36 and LMF = 0.28) and var. albomarginata (SMF = 0.35 and LMF = 0.36) indicated better forage aptitude of these varieties than var. bituminosa (SMF = 0.50 and LMF = 0.19). All varieties showed good values of crude protein and digestibility, although important differences were found between leaf and stem. According to the studied morphological, nutritional and physiological traits, var. albomarginata showed the best aptitude for being introduced as permanent grasslands in some Mediterranean farming systems. However, the possible susceptibility of var. albomarginata to high water content in the soil could limit its introduction. These results help to inform the potential use of these three Canarian B. bituminosa varieties to improve Mediterranean rainfed grasslands of extensive farming systems.

中文翻译：

---

两种水情对加那利群岛三个白茅品种形态性状、营养价值和生理的影响

三种Bituminaria bituminosa品种的形态特征、营养价值和对两种不同水分状况的生理反应：var。白边菜 crassiuscula和var。在温室实验中评估了沥青。实施了两次水情，为期 63 天；水分充足 (WW) 的植物和水分不足 (DW) 的植物都从高土壤含水量（滴水点）开始。这三个品种在减少浇水的情况下表现出相似的空中生物量减少，变种为 50%。albomarginata , 51% for var. 沥青和 43% 的变种。十字花科_ 变量。白蛉在两种水情下都显示出比 var 更低的枝条生物量。bituminosa（WW 植物中 56.2% 和 DW 植物中 55.2%）和 var。crassiuscula（WW 植物中的 52% 和 DW 植物中的 57.8%）。这种较低的枝条生物量可归因于该实验中施加的高初始土壤含水量，影响早期发育。这一假设得到了 var 较低的根生物量产量的支持。albomarginata及其分布。该实验的 DW 处理没有足够的限制性来引起形态改变，而在分析的草料质量变量中，只有灰分受到影响。变量。crassiuscula和var。albomarginata具有较低的比叶面积 (239 cm ²g ^-1和 235 cm ² g ^-1分别）比 var。bituminosa (352 cm ² g ^-1 )，这可能代表了对高光强度和温度条件的重要适应。var 的茎质量分数 (SMF) 和叶质量分数 (LMF) 的值。crassiuscula (SMF = 0.36 和 LMF = 0.28) 和 var。albomarginata（SMF = 0.35 和 LMF = 0.36）表明这些品种的牧草适应性优于 var。沥青（SMF = 0.50 和 LMF = 0.19）。尽管在叶和茎之间发现了重要差异，但所有品种都显示出良好的粗蛋白和消化率值。根据研究的形态、营养和生理特征，var。albomarginata在一些地中海农业系统中显示出作为永久性草原引入的最佳能力。然而，var 的可能敏感性。albomarginata土壤中的高含水量可能会限制其引入。这些结果有助于告知这三种 Canarian B. bituminosa品种的潜在用途，以改善广泛耕作系统的地中海雨养草原。