供氮形态与水平对玉米苗期耐低磷胁迫的生物学效应  

Biological Effect of Nitrogen Form and Supply Level on Maize Seedling Biological Characteristics under Low Phosphorus Availability Stress

作　　者：周毅[1] 张平[2] 汪建飞[1] 范东坡[1] 高祥[1] 

机构地区：[1]安徽科技学院城建与环境学院,安徽凤阳233100 [2]南京农业大学资源与环境科学学院,江苏南京210095

出　　处：《安徽科技学院学报》2012年第3期19-26,共8页Journal of Anhui Science and Technology University

基　　金：国家公益性行业(农业)科研专项(201103004);安徽省优秀青年科技基金项目(10040606Y02);安徽自然科学基金项目(090411002)

摘　　要：采用营养液培养方式,探讨和比较硝态氮(NO3--N)和铵态氮(NH4+-N)两种不同供氮形态及其供应水平(0、3、7.5、15、22.5、30、37.5 mmol/L)下,供试玉米利民15和皖玉9号的生物学性状对以磷酸钙模拟的低生物有效磷胁迫的适应性差异。结果表明:当供氮水平低于22.5 mmol/L时,对玉米供应NH4+-N或NO3--N均可产生提高其对低生物有效磷胁迫适应性的效应。随供氮水平的升高,在两种供氮形态营养条件下,玉米幼苗植株生物量、地上部和根系干重、株高、叶面积和根体积的变化趋势均基本呈现报酬递减规律,而当供氮水平在0～7.5 mmol/L变化时,玉米的生物量干重均出现最高值。不同品种玉米对NH4+-N和NO3--N营养的响应既存在共性:NO3--N营养玉米植株株高和根体积始终高于NH4+-N营养植株,但也存在基因型差异。从植株含磷量分析,当氮水平高于3 mmol/L时,NH4+-N营养利民15的磷含量始终高于NO3--N营养玉米;而皖玉9号则在供NH4+-N水平高于22.5 mmol/L时,出现磷含量低于等氮水平下的NO3--N营养玉米的现象;其中利民15的植株磷含量与其生物量干重之间呈极显著的负相关关系(r=-0.77**,n=11),而皖玉9号的植株磷含量则与其生物量干重之间呈极显著的正相关关系(r=0.96**,n=11)。此外,在等氮水平下,两种供氮形态营养玉米的叶面积、单位叶面积光合速率、单株水平的根系活力之间没有明显的差异,因此,在低生物有效磷胁迫条件下,玉米在不同供氮形态营养条件下的适应性机制不同,其适应性强弱主要取决于是否为适宜的供氮水平。By using the method of nutrient solution culture and simulated low phosphorus availability stress （by adding calcium phosphate）, differences in response of maize to different nitrogen forms （NO3- and NH4＋ ） at lev- els of 0, 3, 7.5, 15, 22.5, 30 and 37.5 mmol/L were analyzed. The result showed that nitrogen nutrition, supplied with either ammonium or nitrate, at levels of lower than 22.5 mmol/L, enhanced low availability of phosphorus stress tolerance of maize plants. Relationship between total biomass, dry weight of shoots and roots, plant height, leaf area and roots volume, and nitrogen supply typically follow a relationship similar to the law of diminishing yield increment. The highest dry weight of maize was observed when nitrogen nutrition was suppliedat level 0 - 7.5 mmol/L. Plant height and roots volume of nitrate - fed maize plants were higher than that of am- monium - fed maize plant supplied with equal nitrogen level. However, response of biomass to nitrogen form dif- fers in maize cultivars. Total biomass, shoots and roots biomass of maize cultivars Limin 15 supplied with nitrate were higher than that of ammonium, while it is different for maize cultivars. On the view of phosphorus nutrition characters, phosphorus content of ammonium -fed maize cultivars Lmin 15 was higher than that of nitrate -fed, when nitrogen was supplied at levels higher than 3 mmol/L. However, phosphorus content of ammonium - fed maize cultivars Wanyu 9 was lower than that of nitrate - fed, when nitrogen was supplied at levels higher than 30 mmol/L. Phosphorus content of maize cultivars Wanyu 9 was significantly negative correlated with that of biomass dry weight （ r = - 0.77＊＊, n = 11 ）, while positive correlationship for maize cultivars Wanyu 9 （ r = 0.96＊＊, n = 11 ）. Furthermore, there is no significant difference in leaf area, photosynthesis rate and roots activity of maize plants supplied with the two nitrogen forms at total plant level. Therefore, acclimation mechanism of maize plant to low availa

关 键 词：氮形态 氮水平 玉米 低生物有效磷胁迫 生物学效应 

分 类 号：S143.1[农业科学—肥料学]