土壤肥力对扁穗雀麦种子产量及其构成因素的影响

Effects of Different Soil Fertility on Seed Yield and Yield Components of Bromus catharticus

为扁穗雀麦种子生产与新品种培育提供理论依据,在土壤肥力不同的2块地(以第二次全国土壤普查养分含量分级标准,分为高肥区和低肥区),研究肥力对9份扁穗雀麦种质材料生殖枝高(x1)、单株平均穗长(x2)、小穗数(x3)、小穗小花数(x4)、种子数(x5)、每穗节数(x6)、小穗长(x7)、小穗宽(x8)、分蘖数(x9)、生殖枝数(x10)、百粒重(x11)和单株种子产量(y)的影响。结果表明:扁穗雀麦种质间的种子产量存在显著差异(P<0.05),在高肥区,最高为9号(来源于福泉市),单株种子产量达8.39g;在低肥区,最高为4号(来源于平坝县天龙镇),产量达5.98g。土壤肥力是影响扁穗雀麦种子产量的主要因素,肥力低降低种子产量及其构成因素的发挥。在高肥区,分蘖数、生殖枝高和小穗宽是影响扁穗雀麦产量的主要因素;在低肥区,主要影响因素是百粒重、种子数、生殖枝数与小穗小花数。其高肥区(y1)与低肥区(y2)的回归方程分别为y1=-4.436+0.078x1-4.089x8+0.597x9,y2=-2.658-0.538x4+0.014x5-0.443x10+4.790x11。在肥力较好地块进行扁穗雀麦种子生产时,其增产的技术关键是增加植株分蘖数与生殖枝高;在肥力较差或土壤贫瘠的地块,要增加种子的饱满度和成熟种子数,同时应保障生殖枝完成生育期和增加小穗小花的结实率。

The fertile stem height（x1）,average spike length per plant（x2）,spikelet number（x3）,floret number/spikelet（x4）,seed number（x5）,node number/spike（x6）,spikelet length（x7）,spikelet width（x8）,tillering number/plant（x9）,fertile stem number/plant（x10）,100 seed weight（x11）and seed yield/plant（y）of 9 B.catharticus germplasm materials planted on the soils with high fertility and low fertility were determined to provide the theoretical basis for seed production and new variety breeding of B.catharticus.Results：There is a significant difference（P〈0.05）in seed yield between different B.catharticus germplasm materials.Seed yield per plant of No.9（Fuquan City）planted on the soil with high fertility reaches 8.39 g and seed yield per plant of No.4（Pingbao County）planted on the soil with low fertility is 5.98 g.Soil fertility is the main factor to influence seed yield of B.catharticus and low soil fertility reduces seed yield and performance of yield component.The tillering number,fertile stem height and spikelet width of B.catharticus planted on the soil with high fertility are main factors to influence seed yield of B.catharticus and 100 grains weight,seed number,fertile stem number and floret number/spikelet of B.catharticus planted on the soil with low fertility are main factors to influence seed yield of B.catharticus.The regression equations of high soil fertility（y1）and low soil fertility（y2）are y1=-4.436＋0.078x1-4.089x8＋0.597x9 and y2=-2.658-0.538x4＋0.014x5-0.443x10＋4.790x11.The key techniques to increase seed yield of B.catharticus planted on the soil with high fertility are increasing tillering number and fertile stem height.The key techniques to increase seed yield of B.catharticus planted on the soil with low fertility are increasing seed fullness and mature seeds,guaranteeing whole growth period of fertile stems and improving setting percentage of floret number/spikelet.