摘要
【目的】黄瓜和番茄是我国主栽蔬菜种类,育苗过程中容易遭遇高温、高湿、弱光等不良环境,导致幼苗下胚轴徒长,严重影响后期丰产性。在控制幼苗徒长的实际操作中,利用植物生长调节剂、机械刺激、补光、温度调节、水分控制等调控方法容易受到多种因素影响而效果不佳。本文研究高浓度营养液对黄瓜和番茄幼苗下胚轴徒长的抑制作用,以期提出一种有效制御幼苗徒长的方法。【方法】试验以Hoagland标准营养液配方为基础浓度(设为1.0C),通过成比例增减大量元素组分用量而不改变微量元素组分用量,组成0.5C、2.5C、5.0C、7.5C、10.0C和12.5C 6个浓度。以0.5C为对照,在日光温室条件下分别对黄瓜和番茄幼苗进行灌施处理。待幼苗生长至子叶平展期时,测定黄瓜和番茄幼苗形态及生长指标,研究营养液浓度对幼苗下胚轴细胞长度、生长速率及内源激素含量的影响;随后对幼苗进行0.5C低浓度营养液的恢复生长处理,待幼苗生长至第一真叶平展期时,再次进行幼苗形态及生长指标的测定,从而确定高浓度营养液对黄瓜和番茄下胚轴徒长的抑制效果及机制,并确定最适合制御幼苗徒长的营养液浓度。【结果】6种浓度营养液对黄瓜和番茄幼苗下胚轴徒长的影响结果为:1)高浓度营养液显著提高了基质EC值(r=0.99),黄瓜和番茄幼苗在子叶平展期其下胚轴生长受到明显抑制,下胚轴长度、绝对生长速率和含水量均呈下降趋势,下胚轴皮层薄壁细胞轴/径向生长也受到影响。与对照相比,10.0C营养液处理下黄瓜和番茄幼苗下胚轴皮层薄壁细胞缩短为49%和48%。2)随着营养液浓度的增加,黄瓜和番茄下胚轴内源激素含量发生显著变化,其中赤霉酸(GA3)、玉米素核苷(ZR)含量呈降低趋势,而脱落酸(ABA)含量呈升高趋势,且ABA含量与下胚轴长度呈极显著负相关关系(P<0.01)。生长素(IAA)含量在不
Objectives]Cucumber (Cucumis sativus) and tomato (Lycopersicon esculentum) are main cultivated vegetable species in China. The seedling growth in breeding processes is vulnerable to disadvantageous environments, such as high temperature, high humidity and weak light, which lead to excessive hypocotyl stretch and reduce yield at later stage.Several methods such as plant growth regulators, mechanical stimulations, supplement of light, temperature modulation and water limitation are used to prevent excessive hypocotyl stretch, but the effects are always not satisfied due to complicated influence factors.To develop an effective method for controlling hypocotyl stretch in cucumber and tomato seedlings, this paper focused on the inhibition effect of high strength nutrient solution on hypocotyl stretch in cucumber and tomato seedlings.[Methods] A concentration of complete macroelement of 1.0 strength Hoagland nutrient solution was defined as fundamental formula ( 1.0 C ) . Other nutrient solution concentration gradients involved in this experiment were 0.5, 2.5, 5.0, 7.5, 10.0 and 12.5C by adding macroelement compositions proportionally without changing the microelements compositions.The 0.5C nutrient solution was set as the control group, and others were the treatment groups.After watering cucumber and tomato seedlings by different nutrient solutions in greenhouse conditions, the growth parameters were measured, and the nutrient solution effects on hypocotyl cortical cell length, growth rate and phytohrmone levels were determined at the cytoledon extending stage.Then seedlings were rewatered by the 0.5C nutrient solution to restore the inhibition growth of hypocotyl stretch.The growth parameters were measured at the first true leaves extending stage.The effects and mechanism of high nutrient solution on inhibiting hypocotyl stretch were determined, and the optimal strength was acquired by appropriate effect on cucumber and tomato seedlings.[Results]The effects of six strength ( 0.5, 2.5, 5.0, 7.5, 10.0 and 12.5C )
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2014年第5期1234-1242,共9页
Journal of Plant Nutrition and Fertilizers
基金
公益性行业(农业)科研专项(201303014)
现代农业产业技术体系建设专项资金(CRAS-25)资助
关键词
黄瓜
番茄
下胚轴
霍格兰营养液
cucumber
tomato
hypocotyl
Hoagland's nutrient solution
