水分亏缺对小麦穗部光合特性及花前^(14)C-同化物分配的影响  

Photosynthetic Characteristics of Spike and Distribution of ^(14)C-Assimilates Accumulated before Anthesis in Wheat under Water Deficit Condition

作　　者：张磊[1] 吕金印[1] 贾少磊[1] 

机构地区：[1]西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《作物学报》2013年第8期1514-1519,共6页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31271624)资助

摘　　要：为明确干旱胁迫对小麦穗部花前同化物合成和转运的影响,选用旱地品种西农928和水分敏感品种郑引1号,通过14CO2标记技术研究了水分亏缺下穗部光合特性及穗部花前同化物的转运和分配规律。水分亏缺条件下,西农928灌浆前期、中期的穗部净光合速率、颖壳中叶绿素含量及可溶性总糖含量略有下降,而郑引1号显著下降。成熟期西农928的水分利用效率上升1.7%(P>0.05),籽粒中14C-同化物分配率略降3.2%(P>0.05);而郑引1号水分利用效率下降16.9%(P<0.05),籽粒中花前14C-同化物分配率上升7.8%(P<0.05)。试验表明,水分亏缺对西农928穗部光合的影响有限;适度水分亏缺促进了水分敏感品种郑引1号颖壳及内外稃中花前14C-同化物向籽粒的转运,相对提高了其穗部花前光合同化物对籽粒灌浆的贡献率。Photosynthate in spike has an important contribution to grain yield in wheat.Two wheat cultivars,Xinong 928（drought resistant） and Zhengyin 1（drought sensitive）,were labeled with 14CO2 seven days before anthesis to monitor the drought-responses in photosynthetic characteristics and dry matter translocation of spike during grain-filling period.Under water-deficit condition,the net photosynthetic rate of spike and contents of chlorophyll and sugar in glume at early-and mid-filling stage had slight declines in Xinong 928 but significant decreases in Zhengyin 1.At maturity stage,Xinong 928 showed no significant variations in water use efficiency and 14C-assimilate ratio in grain under water-deficit condition;whereas,Zhengyin 1 had a significant decrease（16.9%,P ＆lt; 0.05） in water use efficiency and a significant increase（7.8%,P ＆lt; 0.05） in 14C-assimilate ratio in grain.These results suggested that water deficit had limited influences on the photosynthesis of spike in the drought-resistant cultivar Xinong 928;however,moderate drought stress stimulated the translocation of dry matter from glume,palea,and lemma into grain in the drought-sensitive cultivar Zhengyin 1,which resulted in the increase of14C-assimilate ratio in spike before anthesis.

关 键 词：小麦 水分亏缺 穗部光合特性 干物质转运 14C-标记 

分 类 号：S512.1[农业科学—作物学]