CAJ | 학술논문

研究了浓度为100 mmol/L，pH值分别为7．0，8．0，9．0，10．0碱性盐胁迫下桑树幼苗叶片的叶绿素含量、相对含水率、细胞膜透性变化以及叶绿素荧光特性对光强的响应特点。结果表明，在盐溶液浓度为100 mmol/L时，pH值7．0～9．0的碱性盐胁迫下，随pH值的升高桑树幼苗叶片的叶绿素含量和叶片含水率降低幅度较小，丙二醛含量未明显增加，细胞膜未发生明显的过氧化。桑树幼苗叶片的PSⅡ生理功能也未受到明显的抑制，桑树幼苗叶片可以通过增加以叶黄素循环为主的非辐射能量耗散机制来保护PSⅡ反应中心的正常生理功能，叶片PSⅡ可以保证正常的电子传递能力及光能的利用能力，即桑树幼苗叶片的PSⅡ功能具有一定的耐碱性盐能力。但当pH值达10．0时，浓度为100 mmol/L的碱性盐胁迫下桑树幼苗叶片的膜系统受到破坏、叶片大量失水、单位面积叶绿素含量特别是叶绿素a含量明显降低。另外，桑树幼苗叶片的光合电子传递受阻，吸收的光能不能完全用于光合电子传递，同时依赖于叶黄素循环的非辐射能量耗散机制也受到了抑制，从而导致叶片中过剩光能（1-qP ）/NPQ大量积累，迫使PSⅡ反应中心的关闭程度和失活比例增加，桑树幼苗叶片可能通过反应中心失活的方式来减轻PSⅡ反应中心的压力，但这同时使桑树幼苗叶片对光能的利用能力特别是对高光强的利用能力降低。
연구료농도위100 mmol/L，pH치분별위7．0，8．0，9．0，10．0감성염협박하상수유묘협편적협록소함량、상대함수솔、세포막투성변화이급협록소형광특성대광강적향응특점。결과표명，재염용액농도위100 mmol/L시，pH치7．0～9．0적감성염협박하，수pH치적승고상수유묘협편적협록소함량화협편함수솔강저폭도교소，병이철함량미명현증가，세포막미발생명현적과양화。상수유묘협편적PSⅡ생리공능야미수도명현적억제，상수유묘협편가이통과증가이협황소순배위주적비복사능량모산궤제래보호PSⅡ반응중심적정상생리공능，협편PSⅡ가이보증정상적전자전체능력급광능적이용능력，즉상수유묘협편적PSⅡ공능구유일정적내감성염능력。단당pH치체10．0시，농도위100 mmol/L적감성염협박하상수유묘협편적막계통수도파배、협편대량실수、단위면적협록소함량특별시협록소a함량명현강저。령외，상수유묘협편적광합전자전체수조，흡수적광능불능완전용우광합전자전체，동시의뢰우협황소순배적비복사능량모산궤제야수도료억제，종이도치협편중과잉광능（1-qP ）/NPQ대량적루，박사PSⅡ반응중심적관폐정도화실활비례증가，상수유묘협편가능통과반응중심실활적방식래감경PSⅡ반응중심적압력，단저동시사상수유묘협편대광능적이용능력특별시대고광강적이용능력강저。
In this paper ,taking mulberry seedlings as test material ,the effects of diffierent concentration alka-line salt(Na2CO3)stress(Density of concentration was 100 mmol/L and value of pH were 7.0,8.0,9.0 and 10.0) on chlorophyll content , relative water content , cell membrane permeability changes and Chlorophyll fluorescence characteristics in mulberry seedlings were investigated .The results showd that under the alkaline salt stress with pH values in 7 .0-9 .0 ,chlorophyll content and relative water content were reduced smaller ,malondialdehyde contents were no apparent increased and peroxidation of membrane were no occurred significantly .Meanwhile ,the inhibitions of PSⅡphysiological function were also not being obvious in leaves of mulberry seedlings .However,the leaves of mulberry seedlings could protect normal physiological function of PSⅡreaction centers by non-radiative energy dis-sipation mechanism which was xanthophyll-regulated thermal energy dissipation as the main , thus leaves of PSⅡcould guarantee the normal capacity of electronic transport and utilization of solar energy .Namely,the PSⅡin Leav-es of Mulberry seedlings had an alkaline salt-tolerance ability in some degree .But when the pH up to 10.0,mem-brane systems in leaves of Mulberry seedlings were damaged ,leaves water loss were seriously ,and Per unit area of chlorophyll content were appreciably reduced which reducing of chlorophyll a content particularly clear .Further-more,photosynthetic electron transports were hindered in leaves of Mulberry seedlings , and the absolute energy could used in photosynthetic electron transports imcompletely .The non-radiative energy dissipation mechanisms by xanthophyll cycle were inhibited simultaneously , which resulted in an accumulated excess light energy ( 1 -q P )/NPQ in the leaves.Then closure and deactivation of PSⅡreaction centers accelerated rapidly ,which might be a way to alleviate the pressure on PSⅡreaction centers ,but at the same time decreased the capacity of solar energy utili-zation in particular to high light intensity utilization in the leaves of Mulberry seedlings .