结球甘蓝叶水提液对糯玉米和西葫芦幼苗生长的化感作用

  目的  探讨结球甘蓝Brassica oleracea var. apitata化感作用与茬口障碍的关系，为建立合理轮作制度提供理论依据。  方法  以结球甘蓝风干叶片为供试材料，以适宜山西寒旱区栽培且经济收益相对较高的2种作物:糯玉米Zea mays和西葫芦Cucurbita pepo作为受体植物，采用室内生物测定法，比较了不同质量浓度结球甘蓝叶水提液对上述2种受体作物幼苗营养生长的影响，并计算相应的化感效应指数和综合效应指数。  结果  当结球甘蓝叶水提液质量浓度≥0.06 kg·L?1时均显著(P＜0.05)抑制盆栽糯玉米苗期根系与地上部的生长。仅当添加的结球甘蓝叶水提液质量浓度为0.10 kg·L?1时，显著降低(P＜0.05)西葫芦的苗高与根长。在水提液同一质量浓度下，对糯玉米根长的化感抑制作用始终大于苗高。对西葫芦则表现为当结球甘蓝叶水提液质量浓度≥0.08 kg·L?1时，对根长的化感抑制作用大于苗高；当水提液质量浓度降至0.06 kg·L?1时，对根长的化感抑制作用小于苗高。由综合效应指数可知，对西葫芦的化感综合抑制作用要小于糯玉米。  结论  西葫芦可用于结球甘蓝轮作体系，以减轻化感作用而引起的障碍。图2表3参28

Allelopathic effect of water extract of Brassica oleracea var. capitata leaves on seedling growth of Zea mays and Cucurbita pepo

  Objective  The objective is to probe the relationship between toxicity of Brassica oleracea var. capitata and stubble obstacles, so as to provide a theoretical basis for establishing a reasonable crop rotation system.   Method  Taking the air-dried leaves of B. oleracea var. capitata as test materials, two crops species (Zea mays and Cucurbita pepo) with relatively high economic benefits and suitable for cultivation in cold and arid area of Shanxi were used as receptor. The effects of water extract from B. oleracea var. capitata leaves with four mass concentrations 0, 0.06, 0.08 and 0.10 kg·L?1 on the nutritional growth of the above two receptor crops were compared by indoor bioassay method, and the corresponding allelopathic effect index and comprehensive effect index were calculated.  Result  When the water extract concentration of B. oleracea var. capitata leaves was ≥0.06 kg·L?1, the growth of roots and shoots of potted Z. mays seedling could be significantly inhibited (P＜0.05). The seedling height and root length of C. pepo were significantly reduced (P＜0.05) only when the mass concentration of water extract of B. oleracea var. capitata leaves was 0.10 kg·L?1. At the same concentration, the allelopathic inhibition on root length of Z. mays was always greater than that on seedling height. For C. pepo, the allelopathic inhibition on root length was greater than that on seedling height when the water extract concentration of B. oleracea var. capitata leaves was ≥0.08 kg·L?1. When the mass concentration decreased to 0.06 kg·L?1, the allelopathic inhibition on root length was less than that on seedling height. According to the results of allelopathic comprehensive effect index, the allelopathic comprehensive inhibition on C. pepo was less than that on Z. mays.   Conclusion  C. pepo can be used in the rotation system of B. oleracea var. capitata to alleviate the obstacles caused by other toxicity. Ch, 2 fig. 3 tab. 28 ref.]