摘要
以白杨派单交和双交杂种无性系1年生扦插苗为材料,分析不同盐胁迫条件下无性系的生长及光合系统的反应,并对无性系间的差异进行比较。研究表明:盐胁迫对叶片生长、苗高生长及苗木生物量积累均产生不同程度的影响。随着盐浓度升高,各项生长指标迅速下降,但下降的幅度不同,苗木生物量积累受影响最大。茎叶生长对盐胁迫的敏感性大于根系生长,从而导致根/(茎+叶)生物量随盐胁迫的发展而升高。盐胁迫下4个无性系的净光合速率(Pn)日变化基本上都呈单峰曲线,但随胁迫加强,Pn值迅速降低。盐胁迫下,叶位从幼到老,Pn表现为单峰型变化,中部功能叶Pn值最大,嫩叶和老叶较小,盐胁迫对无性系嫩叶Pn几乎无影响,却显著降低中部功能叶和老叶的Pn值,且随着胁迫时间延长,对叶片Pn的影响加强。盐胁迫降低各无性系的叶绿素含量,且使叶绿素荧光诱导动力学曲线发生明显变化,其参数qN(荧光非光化学猝灭系数)值随盐浓度增加而上升,而qP(荧光光化学猝灭系数)、Fv/Fo(PSⅡ潜在活性)值随盐浓度增加而下降。盐胁迫对双交杂种无性系B430影响最小,单交无性系毛新杨和亲本新疆杨次之,亲本毛白杨对盐胁迫反应最敏感。
The growth and photosynthetic system of the clones under different salt stress conditions and the differences among the clones were investigated using one-year-old seedlings of single poplar hybridization clones （ Populus tomentosa × P. alba var. pyramidalis） , double cross poplar hybridization clones [ （P. tomentosa x P. alba var. pyramidalis ） × （P. alba × P. tremula） 1 and their parent species （P. tomentosa and P. alba var. pyramidalis ）. The results indicated that there was genotypic difference in leaf growth, height and dry biomass in response to salt stress. With increasing salinity, the growth factors decreased rapidly, but differently in extent. The dry biomass was affected most under salt stress. The parts above ground of the plant were more susceptible to salt stress than that below the ground, leading to a higher root/stem ratio with increasing salt. The diurnal change of photosynthetic rates （ P, ） in the four clones generally presented a single peak curve, but the P. value decreased quickly with increasing salt stress. Under the salt stress, the P, showed a single peak curve from the young leaves to the aged leaves. The Pn of young leaves was hardly influenced by salt stress but the P, of older leaves decreased significantly. The influence of salt stress on P, of leaves was even stronger with time. It was also found that the chlorophyll content of different clones declined and the curve of chlorophyll fluorescence induction kinetics changed obviously under the salt stress, and the parameter qN （coefficient of fluorescence non-photochemical quenching） increased, but qp （coefficient of fluorescence photochemical quenching） and Fv/Fo （PS Ⅱ photochemical activity） decreased with increasing salt stress. According to the above analysis, the double cross hybrid clones of B430 was resistant, P. alba var. pyramidalis and P. tomentosa × P. alba var. pyramidalis were moderate resistant, P. tomentosa was the most susceptible to salt stress.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2006年第4期19-26,共8页
Scientia Silvae Sinicae
基金
河北省教委博士基金课题。
关键词
白杨派杂种无性系
盐胁迫
生长
净光合速率
荧光动力学
poplar hybridization clones
salt stress
growth
photosynthetic rate
chlorophyll fluorescence induction kinetics
