EFFECT OF IRON SUPPLY ON GROWTH AND PHOTOSYSTEM II EFFICIENCY OF PEA PLANTS
EFFECT OF IRON SUPPLY ON GROWTH AND PHOTOSYSTEM II EFFICIENCY OF PEA PLANTS
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发表时间：
2006
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影响因子：
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通讯作者：
V. Nenova;M. Popov
中科院分区：
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作者：
V. Nenova;M. Popov
以水培法栽培的豌豆植株，从完全缺铁到中毒，都被提供了不同数量的铁（Fe）。每隔7 d（第20 ~ 41天）记录植株生长、叶绿素和类胡萝卜素含量以及叶绿素荧光参数。随着施加应力的加强和延长，铁缺乏或过量通常会导致生长下降。相对生长率（RGR）的降低主要是由于其生理成分净同化率的降低。其形态成分叶面积比（LAR’）也被认为是一个动态成分，但受影响较小。缺铁条件下，叶片质量比（LWR）和比叶面积（SLA）的变化趋势相反。在部分缺铁条件下，试验最后一周植株的RGR值较高，说明植株已经适应了缺铁条件。不同胁迫对叶片表观密度的影响不同，反映了叶片的形态特征。SLA在缺铁条件下呈上升趋势，在缺铁条件下呈下降趋势。缺铁表现为色素含量低，叶绿素a/叶绿素b和类胡萝卜素/叶绿素比值高。叶绿素荧光仅在强褪绿植物中观察到显著变化。缺铁植物在第34天和第41天的实际PSII效率较低（ΦPSII），这是由于开放PSII中心（qP）的比例较低和激发捕获效率较低（Φexc）。PSⅱ的最大量子产率（Fv/Fm）也有所下降。过量的铁使色素含量升高，但对其比例影响不大。
Pea plants, grown hydroponically, were supplied with different amounts of iron (Fe) ranging from complete deficiency to toxicity. Plant growth, chlorophyll and carotenoid content and chlorophyll fluorescence parameters were recorded at 7-day intervals from day 20 to day 41. Growth decrease, caused by Fe deficiency or excess as a rule accrued with strengthening and prolongation of the imposed stress. The observed decrease in relative growth rate (RGR’) was mainly due to the decrease of its physiological component, the net assimilation rate. Being only slightly affected, its morphological component, the leaf area ratio (LAR′) was considered as a dynamic component, too. Opposite trends in the changes of is components, leaf weight ratio (LWR) and specific leaf area (SLA), were observed under Fe deficiency. Under partial Fe deficiency RGR′ was high during the last week of the experiment, suggesting that plants had been adapted to insufficient Fe supply. Stresses differed in regard to their effects on SLA, which reflects leaf morphological peculiarities. SLA tended to increase under Fe deficiency and to decrease under excess Fe supply. Fe deficiency was characterized by low pigment content and high chlorophyll a/chlorophyll b and carotenoids/chlorophylls ratios when chlorosis was well manifested. Significant changes in chlorophyll fluorescence were observed only in strongly chlorotic plants. Plants deprived from iron were marked by low actual PS II efficiency (ΦPSII) at days 34 and 41, which was due to lower proportion of open PS II centers (qP) and to their lower excitation capture efficiency (Φexc). The maximum quantum yield of PS II (Fv/Fm) decreased, too. Excess Fe caused rise in pigments content and only slight disturbance in their ratio.