不同类型小麦光合特性及农艺性状的差异
Difference of Photosynthetic Characteristics and Agronomic Traits in Different Types of Wheat

为探讨陕西类型小麦与黄淮类型小麦光合特性和主要农艺性状的差异，更好地为制定小麦育种目标提供依据，分别选用陕西类型小麦14个品种、黄淮类型小麦7个品种，研究其在孕穗期、开花期、灌浆初期、灌浆后期旗叶的叶绿素相对含量（SPAD）、净光合速率（Pn）、气孔导度（Gs）、胞间CO2摩尔分数（Ci）、蒸腾速率（tr）及农艺性状等指标的差异，对旗叶Pn、旗叶面积、穗粒数、千粒质量、穗长、有效穗数和产量等性状进行聚类分析。结果表明：在开花期，陕西类型小麦旗叶Pn和tr、平均株高、平均千粒质量、平均穗粒数、平均有效穗数和平均产量均低于黄淮类型小麦，旗叶长、旗叶宽、旗叶面积、穗长和芒长分别高于黄淮类型小麦；在欧式距离为5.09处21个小麦品种（系）聚为5个类群。第Ⅰ类群和第Ⅱ类群综合表现良好，第Ⅴ类群综合表现最差，其中黄淮类型小麦主要分布在第Ⅰ、Ⅱ类群，陕西类型小麦在5个类群中均有分布。可见，陕西类型小麦Gs、Ci、SPAD值和旗叶面积变化幅度大，在小麦育种上有选择空间；旗叶Pn和tr有待提高；在表型选择上，小麦旗叶面积、千粒质量、群体密度并非越大越好，最适范围的选择是关键。
To explore the difference in photosynthetic characteristics and main agronomic traits between Shaanxi type and Huanghuai type of wheat,making twenty one wheat varieties as experimental materials that fourteen wheat varieties were Shaanxi type and seven wheat varieties were Huanghuai-type,the study compared the flag leaf chlorophyll relative content (SPAD),net photosynthetic rate (Pn),stomata conductance (Gs),intercellular CO2 mole fraction (Ci),transpiration rate (tr) and agronomic traits at booting stage,flowering stage,early grain filling stage and later grain filling stage.And cluster analysis of Pn of flag leaf,area of flag leaf,kernels per spike,1 000-grain mass,ear length,effective ear number and yield were done too.The results showed that Shaanxi type wheat were lower than Huanghuai type wheat on Pn and tr at flowering stage,plant height,1 000-grain mass,kernels per spike,effective ear number and yield at their average level.While,Shaanxi type of wheat were higher than Huanghuai type of wheat on length of flag leaf, width of flag leaf, area of flag leaf,ear length and awn length at their average level,respectively.The twenty one varieties (lines) of wheat were clustered into five groups when the cutting on the euclidean distance of 5.09.Group Ⅰ and group Ⅱ were better than other groups on photosynthetic characteristics and main agronomic traits,and group Ⅴ was the worst.Huanghuai type wheat was mainly distributed in the group Ⅰ and group Ⅱ,Shaanxi type wheat in five groups was all distributed.It can be concluded that range ability of Shaanxi type wheat of Gs,Ci,SPAD value and flag leaf area were larger,so these traits were good to be chosen at a great range in wheat breeding.Shaanxi type wheat’s Pn and tr of flag leaf should be further improved.At phenotypic screening in wheat,flag leaf area and 1 000-grain mass and density,it were not always the bigger,the better,and it is key to choose optimal range.