苗前补灌对内蒙古黄土高原旱作区谷子生长及光合特性的影响

Effects of pre-seedling supplementary irrigation on the growth and photosynthetic characteristics of millet in the dry farming area of the Loess Plateau in Inner Mongolia

【目的】筛选适宜内蒙古黄土高原旱作区种植的优良谷子品种。【方法】以8个谷子品种为研究对象,采用裂区试验设计,设置苗前补灌与水分亏缺2个处理,采用主成分分析法对比分析谷子品种生长特征及光合特性变化规律。【结果】苗前补灌可显著影响谷子品种的生长和光合特性。与水分亏缺处理相比,金苗K1的出苗率提高最高(6.56%),其次为张杂谷13号(提高4.44%);金苗K1和张杂谷13号的株高表现较好,分别为30.5、30.3 cm,提高了15.21%、6.27%,均与其他品种相比差异显著(P<0.05);张杂谷13号的茎粗和干物质积累量表现较好,分别为5.45 mm、0.598 g,提高了12.60%、5.65%,与其他品种相比差异显著(P<0.05),其次为金苗K1,分别提高了16.56%、4.98%。水分亏缺处理下,张杂谷13号和金苗K1的叶面积指数受干旱影响较小,分别为0.94、0.83;张杂谷13号的相对叶绿素含量最高,为51.18。张杂谷13号和金苗K1的气孔导度在2个处理下均表现较好,显著高于其他品种(P<0.05),苗前补灌处理较水分亏缺处理分别提高了4.45%和4.36%;冀谷168和金苗K1的净光合速率显著高于其他品种(P<0.05),张杂谷13号在水分亏缺处理下表现最好,为33.18μmol/(m^(2)·s),较苗前补灌仅降低了1.99%;张杂谷13号和金苗K1的蒸腾速率均表现较好,显著高于其他品种(P<0.05),苗前补灌处理较水分亏缺处理分别提高了4.39%和3.79%。张杂谷13号和金苗K1的水分利用效率在2个处理下均表现较好,水分亏缺导致叶片光合水分利用效率有所提高,分别提高了11%、7%。【结论】张杂谷13号、金苗K1可作为内蒙古黄土高原旱作区谷子抗旱保苗优势品种推广种植。

【Objective】To screen excellent millet varieties suitable for planting in the dry farming area of the Loess Plateau in Inner Mongolia.【Methods】Using 8 millet varieties as research objects and split plot experiment design,two treatments of pre-seedling supplementary irrigation and water deficit were set up.The growth characteristics and photosynthetic characteristics of millet varieties were compared and analyzed by principal component analysis.【Results】Pre-seedling supplemental irrigation significantly affected the growth and photosynthetic characteristics of millet varieties.Compared with water deficit treatment,Jinmiao K1 had the highest(6.56%)seedling emergence rate,followed by Zhangzagu No.13(4.44%);Jinmiao K1 and Zhangzagu No.13 had better plant height performance,at 30.5 cm and 30.3 cm,respectively,increased by 15.21%and 6.27%and were significantly different from other varieties(P<0.05);Zhangzagu No.13 had better stem diameter and dry matter accumulation at 5.45 mm and 0.598 g,respectively,increased by 12.60%and 5.65%,and were significantly different from other varieties(P<0.05),followed by Jinmiao K1,which increased by 16.56%and 4.98%,respectively.Under the water deficit treatment,the leaf area index of Zhangzagu No.13 and Jinmiao K1 were less affected by drought at 0.94 and 0.83,respectively;the relative chlorophyll content of Zhangzagu No.13 was the highest at 51.18.The stomatal conductance of Zhangzagu No.13 and Jinmiao K1 was better under both treatments,significantly higher than that of other varieties(P<0.05),4.45%and 4.36%higher under pre-seedling supplemental irrigation treatment than water deficit treatment,respectively.The net photosynthetic rates of Jigu 168 and Jinmiao K1 were significantly higher than that of other varieties(P<0.05).Under water deficit treatment,Zhangzagu No.13 had the best net photosynthetic rate at 33.18μmol/(m^(2)·s),which was 1.99%lower than that of pre-seedling supplementary irrigation.The transpiration rates of Zhangzagu No.13 and Jinmiao K1 were better and significantly higher than that of other varieties(P<0.05),4.39%and 3.79%higher under pre-seedling supplemental irrigation treatment than water deficit treatment,respectively.Zhangzagu No.13 and Jinmiao K1 had better water use efficiency under both treatments.Water deficit led to an increase in leaf photosynthetic water use efficiency,the two varieties increased by 11%and 7%,respectively.【Conclusion】Zhangzagu No.13 and Jinmiao K1 could be promoted as the dominant varieties of millet for drought resistance and seedling protection in the dry farming area of the Loess Plateau in Inner Mongolia.