不同甘薯品种抗旱性评价及耐旱指标筛选

在人工控水条件下,以15个甘薯品种为试验材料,设置干旱胁迫和正常灌水2个处理,研究了干旱胁迫条件下不同甘薯品种产量和农艺性状差异。根据产量抗旱系数法分级,抗旱品种(抗旱系数≥0.6)为济薯21、济薯25、济徐23、济薯15、烟薯25;中等抗旱品种(0.4≤抗旱系数0.6)为徐薯18、济薯26、北京553、济紫薯2号、济薯18;不抗旱品种(抗旱系数0.4)为郑薯20、济紫薯3号、济薯22、济紫薯1号、凌紫。干旱胁迫导致甘薯的叶片数、蔓长、叶面积系数和生物量下降,品种间降幅不同,抗旱性强的品种降幅小,抗旱性弱的品种降幅大。这些农艺性状指标与甘薯品种的抗旱性呈显著正相关,可作为甘薯品种抗旱性鉴定的指标。徐薯18可作为甘薯品种抗旱性鉴定的标准品种。

Evaluation of drought tolerance and screening for drought-tolerant indicators in sweetpotato cultivars

Field experiments were conducted under a rain proof shelter using 15 sweetpotato cultivars with drought stress treatment and well-watered treatment. The yield and agronomic traits of different sweetpotato cultivars under drought stress were studied. The sweetpotato cultivars were classified according to the drought resistance coefficient of each cultivar. The drought-tolerant cultivars (DC ≥ 0.6) included Jishu 21, Jishu 25, Jixu 23, Jishu 15, and Yanshu 25. The moderate drought-tolerant cultivars (0.4 ≤ DC < 0.6) included Xushu 18, Jishu 26, Beijing 553, Jizishu 2, and Jishu 18. The drought-sensitive cultivars (DC < 0.4) included Zhengshu 20, Jizishu 3, Jishu 22, Jizishu 1, and Ayamaraski. Drought stress caused the decline of leaf number per plant, vine length, leaf area index and biomass which was different among cultivars. The impact of drought stress on drought-tolerant cultivars was lower than that of drought-sensitive cultivars. Under drought stress, these were significant positive correlations of drought resistance with leaf number per plant, vine length, leaf area index and biomass of different cultivars. All the agronomic traits could be used as a comprehensive evaluation index for identifying drought resistance of sweetpotato cultivars. Xushu 18 could be used as a control cultivar in the identification and screening of drought tolerance.