CAJ | 학술논문

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、37．5mmol／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22．5mmol／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0-7．5mmol／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NO3- -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3mmoL／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22．5mmoL／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。
채용영양액배양방식，탐토화비교초태담（NO3- -N）화안태담（NH4＋-N）량충불동공담형태급기공응수평（0、3、7．5、15、22．5、30、37．5mmol／L）하，공시옥미이민15화환옥9호적생물학성상대이린산개모의적저생물유효린협박적괄응성차이。결과표명：당공담수평저우22．5mmol／L시，대옥미공응NH4＋ -N혹NO3- -N균가산생제고기대저생물유효린협박괄응성적효응。수공담수평적승고，재량충공담형태영양조건하，옥미유묘식주생물량、지상부화근계간중、주고、협면적화근체적적변화추세균기본정현보수체감규률，이당공담수평재0-7．5mmol／L변화시，옥미적생물량간중균출현최고치。불동품충옥미대NH4＋ -N화NO3- -N영양적향응기존재공성：NO3- -N영양옥미식주주고화근체적시종고우NO3- -N영양식주，단야존재기인형차이。종식주함린량분석，당담수평고우3mmoL／L시，NH4＋ -N영양이민15적린함량시종고우NO3- -N영양옥미；이환옥9호칙재공NH4＋ -N수평고우22．5mmoL／L시，출현린함량저우등담수평하적NO3- -N영양옥미적현상；기중이민15적식주린함량여기생물량간중지간정겁현저적부상관관계（r=-0．77＊＊，n=11），이환옥9호적식주린함량칙여기생물량간중지간정겁현저적정상관관계（r=0．96＊＊，n=11）。차외，재등담수평하，량충공담형태영양옥미적협면적、단위협면적광합속솔、단주수평적근계활력지간몰유명현적차이，인차，재저생물유효린협박조건하，옥미재불동공담형태영양조건하적괄응성궤제불동，기괄응성강약주요취결우시부위괄의적공담수평。
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 availability phosphorus stress might be different between nitrogen form treatments. Tolerance of maize plants to the stress was due to optimal nitrogen level rather than nitrogen form.