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作 者 ：张建恒1;李宾兴1;王斌2;郭程瑾1;李雁鸣1;肖凯1

期 刊 ：植物营养与肥料学报 2006年 12卷 2期 页码：169-176

关键词：小麦；磷效率；光合作用；杂种优势；

Keywords:wheat, P efficiency, photosynthesis, heterosis,

摘 要 ：以典型的磷低效(L)、吸收高效(H1)和利用高效(H2)的小麦品种及以上述品种为亲本配制的杂种F₁-1(L×H1)和F₁-2(L×H2)为材料,对上述品种和杂种F₁的光合特性及其生理机制进行了研究。结果表明,缺磷条件下,随着叶片生长进程,供试品种和杂种F₁旗叶CO₂传导参数气孔导度(G_s)、叶肉导度(G_m)和碳酸酐酶(CA)活性;旗叶叶绿素含量(Chl)、光合速率(P_n)、叶绿体无机磷(P_I)浓度和Mg²⁺-ATPase活性、可溶蛋白含量(SP)和RuBPCase活性均不断降低。不同磷效率类型品种相比,旗叶各测定时期上述参数均以L较低,H1和H2较高。与各自亲本相比,F₁-1和F₁-2各测定时期的光合生理参数多表现出明显的优势。表明磷高效小麦品种(H1和H2)以及杂种叶片光合碳同化特性的相对提高,是由于其光合器官捕获光能的能力较强、光合作用气孔限制和非气孔限制的程度较低和暗反应速率较高综合作用的结果。其中,磷高效品种及杂种F1叶绿体Pi供应量的增多,在维持光合器官的结构和功能中可能具有重要作用。研究还表明,供试不同磷高效小麦品种之间(吸收高效H1和利用高效H2)尽管在磷的吸收和利用特征上表现明显不同,但在叶片的光合碳同化特性及其内在生理机制上表现相似,表明控制小麦磷素吸收与利用的遗传基因位点可能与控制光合器官结构与功能的遗传位点不存在紧密连锁。在低磷胁迫条件下,充分利用杂种F₁在光合碳同化特性上的杂种优势,对于改善小麦对磷素的吸收和利用以及促进子粒产量的增加具有潜在的应用价值。

Abstract:Using the typical wheat varieties with low P(phosphorus) efficiency(L),high P absorption efficiency(H1),high P utilization efficiency of P(H2) and hybrid F₁-1(L×H1),F₁-2(L×H2) as the experimental materials to study their photosynthesis and physiological mechanisms.The results showed that under Pideficiency condition,with the growing process of the flag leaf,the CO₂ conductance parameters,stomatal conductance(G_s),mesophyll conductance(G_m) and carbonic anhydrase(CA) activity,the chlorophyll content(Chl) and the photosynthetic rate(P_n),as well as the inorganic phosphorus(P_i) concentration in the chloroplast,Mg²⁺-ATPase activity,soluble protein content(SP) and RuBPCase activity,were all decreased.All captioned physiological parameters in H1 and H2 were higher than those in L.Compared with parents,almost all heterosis values(super-average value of parents) of captioned physiological parameters in F₁-1 and F₁-2 were higher,indicating the improvement of photosynthesis in the wheat varieties with high P efficiency and the hybrid F₁ resulted from their higher light harvesting capacity,lower stomatal limitation and non-stomatal limitation of CO₂ conductance,and higher dark reaction rate of photosynthesis;thereinto,the high supplication of Pi to the chloroplast in the wheat varieties with high P efficiency and in the hybrid F₁ maybe played an important role in maintaining the structure and function of photosynthetic organ under Pi stress condition,by which to some extent physiological process of the photosynthesis was improved.In this study,though H1 and H2 showed dramatic differences on P absorption and P utilization characteristics,their photosynthetic characteristics and physiological mechanisms were very similar,indicating the gene locus for P absorption and utilization are probable not tightly linkage to that for structure and function of photosynthetic organ.Under Pi-deficient condition,it seems that sufficient utilizing heterosis advantage of hybrid F₁ on photosynthesis has latent application value to promote P absorption and utilization and increase grain yield of wheat.

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