Abstract The objective was to evaluate water‐soluble carbohydrate (WSC) and crude protein (CP) concentration of perennial ryegrass (PRG) cultivars with different genetic potential for producing WSC under two contrasting agronomic managements in temperate climate (southern Chile). A 4 × 2 factorial design was randomly allocated to 24 plots (31 m2 each, three blocks): four PRG cultivars (diploid standard cultivar, “2nSt”; tetraploid standard cultivar, “4nSt”; diploid high sugar cultivar developed in New Zealand, “2nHSNZ”; and tetraploid high sugar cultivar developed in Europe, “4nHSEU”) and two agronomic managements (“favourable,” defoliations at three leaves per tiller and nitrogen (N) fertilization rate of 83.3 kg N ha−1 year−1; “unfavourable,” defoliations at two leaves per tiller and N fertilization rate of 250 kg N ha−1 year−1). Herbage samples were collected in early spring, spring, summer and autumn. Concentration of WSC did not differ among cultivars in spring and summer, averaging 194 and 251 g/kg DM, respectively. The cultivar 4nHSEU had the greatest WSC concentration in early spring and autumn (187 and 266 g/kg DM, respectively) and the greatest CP concentration across samplings (average 230 g/kg DM). Favourable management improved WSC concentrations in early spring and summer and decreased CP in spring, summer and autumn. Annual DM yield did not vary with cultivar or management, averaging 8.43 t/ha. Within a 12‐month study at one site in a temperate environment in southern Chile, PRG cultivars have not shown a consistent expression of the “high sugar” trait, where a genetic × environment interaction might be operating.

中文翻译：

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多年生黑麦草品种的“高糖”特性是否在温带气候条件下表现出来？

摘要 目的是评估温带气候（智利南部）两种对比农艺管理下具有不同遗传潜力的多年生黑麦草（PRG）品种的水溶性碳水化合物（WSC）和粗蛋白（CP）浓度。采用 4 × 2 析因设计随机分配到 24 个地块（每个地块 31 m2，三块）：四个 PRG 品种（二倍体标准品种，“2nSt”；四倍体标准品种，“4nSt”；新西兰开发的二倍体高糖品种， “2nHSNZ”；以及欧洲开发的四倍体高糖品种“4nHSEU”）和两种农艺管理（“有利”，每蘖三叶落叶，氮（N）施肥率为 83.3 kg N ha−1year−1； “不利”，每分蘖两片叶子落叶，施氮量为 250 kg N ha−1 年−1)。早春、春季、夏季和秋季采集牧草样品。春季和夏季各品种的 WSC 浓度没有差异，平均分别为 194 克/千克干物质和 251 克/千克干物质。品种 4nHSEU 在早春和秋季具有最高的 WSC 浓度（分别为 187 和 266 g/kg DM），并且在整个采样中具有最高的 CP 浓度（平均 230 g/kg DM）。有利的管理提高了早春和夏季的 WSC 浓度，并降低了春季、夏季和秋季的 CP。年干物质产量不随品种或管理方式的不同而变化，平均为 8.43 吨/公顷。在智利南部温带环境中的一个地点进行的一项为期 12 个月的研究中，PRG 品种并未表现出一致的“高糖”性状表达，而“高糖”性状可能存在遗传与环境相互作用。