CAJ | 학술논문

为了探寻不同遮阴条件下大豆幼苗叶片的光合响应机理及寻求适度的遮阴比例，本试验模拟田间玉／豆套作，以强耐阴“南豆12号”和弱耐阴“桂夏3号”2个大豆品种为材料，在不遮阴、半侧遮阴（30％，50％，70％）和全遮阴（50％）5个不同遮阴方式下，测定了不同生育期遮阴和复光后大豆幼苗叶片色素含量、光合速率和叶绿素荧光参数的变化。结果表明，随着遮阴程度增加，大豆幼苗叶片的色素含量和初始荧光强度（F 0）增加，叶绿素 a／b 值变小；光合速率（P n ）、最大光化学效率（F v／F m ）、PSⅡ实际光化学效率（ΦPSⅡ）和光化学淬灭系数（qP ）呈先升后降趋势，非光化学淬灭系数（NPQ）则呈先降后升的趋势。遮阴胁迫对2个大豆品种幼苗第四复叶期的影响最为显著。2个品种间比较，“南豆12号”和“桂夏3号”在弱遮阴下都能通过改变色素组分比例、促进光合电子传递等途径提高光能潜力的利用来适应弱光环境。在强遮阴胁迫下，“南豆12号”的 PSⅡ反应中心抗胁迫能力更强，“桂夏3号”则不能及时耗散过剩光能，导致光合机构受到破坏。
위료탐심불동차음조건하대두유묘협편적광합향응궤리급심구괄도적차음비례，본시험모의전간옥／두투작，이강내음“남두12호”화약내음“계하3호”2개대두품충위재료，재불차음、반측차음（30％，50％，70％）화전차음（50％）5개불동차음방식하，측정료불동생육기차음화복광후대두유묘협편색소함량、광합속솔화협록소형광삼수적변화。결과표명，수착차음정도증가，대두유묘협편적색소함량화초시형광강도（F 0）증가，협록소 a／b 치변소；광합속솔（P n ）、최대광화학효솔（F v／F m ）、PSⅡ실제광화학효솔（ΦPSⅡ）화광화학쉬멸계수（qP ）정선승후강추세，비광화학쉬멸계수（NPQ）칙정선강후승적추세。차음협박대2개대두품충유묘제사복협기적영향최위현저。2개품충간비교，“남두12호”화“계하3호”재약차음하도능통과개변색소조분비례、촉진광합전자전체등도경제고광능잠력적이용래괄응약광배경。재강차음협박하，“남두12호”적 PSⅡ반응중심항협박능력경강，“계하3호”칙불능급시모산과잉광능，도치광합궤구수도파배。
This study investigated the photosynthetic response of soybean seedlings under different shading con-ditions.Simulating the field maize/soybean relay-cropping pattern,two soybean cultivars,“Nandou 12”and“Guixia 3”,were utilized to analyze changes in the pigment content,photosynthetic rate and chlorophyll fluo-rescence parameters at different growth stages under shading and during light recovery stages.Five shading treatments were set;no shading,30% partial shading,50% partial shading,70% partial shading and 50% full shading.Shading increased the pigment content and original fluorescence intensity while the chlorophyll a/b ra-tio decreased.Photosynthetic rate,maximal photochemical efficiency,photochemical efficiency and photo-chemical quenching initially increased and then decreased,while non-photochemical quenching initially de-creased before increasing.The soybean seedlings grew strongly under 50% partial shading but growth was poor under 50% full shading.Shading had a marked effect on seedlings at the four-trifoliolate leaf stage;when sha-ded,seedlings accommodated the weak light environment by changing the pigment composition or promoting photosynthetic electron transport.“Nandou 12”showed better shade tolerance and higher photo chemical effi-ciency than “Guixia 3”.“Guixia 3”was unable to dissipate excess light energy under light recovery resulting in severe damage to the photosynthetic system.