高羊茅不同基因型在2个施肥水平和2个收割留茬高度下种子生产性能的比较——I 植株形态比较及其与总籽粒产量的相关性
Compared Seed Production of Tall Fescue Genotypes under Two Fertilizer Application Rates and Two Swathing Stubble Heights——I.Compared Morphological Characters and Their Correlations to the Yield of Whole Seeds

对高羊茅(Festuca arundinacea Schreb)8个基因型在2个肥力下的植株形态进行了比较,并分析了其与总籽粒(清选前)产量的相关性,以期为上海地区高羊茅种子生产提供调控营养生长的技术基础。以移栽后生长2年的6个我们自育的高羊茅性系和2个国外引进的品种(组合)(‘家园’和‘三A’)的植株为材料,于2014-2015年间在上海闵行区轻粘土(pH 7.9)上进行田间试验。于秋季实施15-15-15的N-P2O5-K2O复合肥875 kg/hm2的高养分水平和不施肥的低养分水平(对照)。于籽粒收获时实施两个收割高度,即距离地面6 cm(‘平地刈割整株’)和距离地面45~65 cm(‘收穗’)。试验结果表明,秋季施肥能明显使叶色在初冬转绿,显著提高株高和穗长,而对旗叶面积和总籽粒产量的提高程度随基因型的不同而异。收割高度对总籽粒的产量影响不显著。总籽粒产量分别与株高、穗长和旗叶面积均呈显著正相关关系。由此推论,植株在冬季和早春的色泽可用于营养诊断;施肥使营养体得到充分而不过度的生长,是夺取籽粒高产的物质基础。
Morphological characters were compared and their correlations to the yield of whole seeds(filled-seeds and shrunken seeds)were analyzed in eight genotypes of tall fescue(Festuca arundinacea Schreb)under two application rates of N-P-K compounded fertilizer to provide a technical support basis for the regulation of vegetative growth for high seed production in Shanghai.Plots were laid out on a 2-year-old transplanted stands of six self-bred clones and two imported materials of ‘Plantation’ and ‘Triple A’ blend(control)at Minhang District,Shanghai,on a light clay soil(pH 7.9)between 2014 and 2015.N-P2O5-K2O(15-15-15)compounded fertilizer were applied at the rates of 0(control)and 875 kg/hm2to plots in autumn.Matured plants were swathed at two plant stubble heights:6 cm(‘whole plant harvesting’,swathing the plant from the surface of the soil)and 45-65 cm(‘seed head harvesting’,swathing seed head).Results from this experiment showed that the color of plants obviously turned darker green in early winter,and plant height and panicle length were significantly higher under the fertilization than those under no fertilization.The increased degree of the flag leaf area and yield of whole seeds due to the fertilization varied with genotypes.The swathing stubble heights had no significant effect on the yield of whole seeds.Yield of whole seeds was significantly and positively correlated with plant height,panicle length and flag leaf area respectively.It is inferred that the color of plants in winter and early spring can be used for nutrition diagnosis,and the fertilization enables sufficient but not excessive vegetative growth,which provides material basis for the high seed production.