玻璃温室与田间栽培小麦幼穗分化的比较

Comparative study of spike differentiation in wheat in the glasshouse and field

以河南省大面积种植的弱春性品种"郑麦9023"及半冬性品种"周麦18"为材料,开展了玻璃温室和田间栽培条件下小麦幼穗分化进程的比较研究。结果表明,在小麦全生育期,玻璃温室内平均温度高于田间环境,小麦幼穗分化所需时间极显著低于田间环境(P<0.01)。温度和0℃以上积温升高,小麦幼穗分化进程加快。与田间种植小麦相比,玻璃温室内小麦幼穗分化缩短的时期主要集中在分化前期(出苗-伸长期、单棱期、二棱期)。玻璃温室内小麦幼穗分化持续时间和总积温均随播期推迟而降低,幼穗分化各阶段出现时间亦随播期的推迟而后延。小麦幼穗分化进程存在品种间差异,其中"郑麦9023"幼穗分化持续时间小于"周麦18",各阶段出现的时间亦早于"周麦18"。温度对幼穗分化各时期的影响存在品种间差异。温度升高对"郑麦9023"幼穗分化中期(二棱期、护颖分化期、小花分化期)影响较大,对"周麦18"幼穗分化前期和后期(单棱期、二棱期、药隔分化期)影响较大。积温对"郑麦9023"护颖分化期和"周麦18"药隔分化期、二棱期影响较大。

Spike differentiation is important for reproductive organ formation during wheat growth and development,and is a crucial period influencing grain yield.Spike differentiation depends not only on genetic characteristics but also environmental factors such as temperature.In recent years,rising temperatures and extreme weather associated with global climate change have strongly affected agricultural production and systems. Wheat is an important food crop worldwide and is the main crop grown in Henan province.With the aim of assessing the effects of increasing temperature on wheat spike differentiation,a comparative study of wheat spike differentiation in the glasshouse and field was conducted during 2009/2010.The experimental material comprised ＇Zhengmai 9023＇,which is a semi-spring wheat cultivar,and ＇Zhoumai 18＇,which is a semi-winter wheat cultivar.In the field experiment,seeds were sown on 18 October;in the glasshouse experiment,seeds were sown on 1 November（T1）,15 November（T2） and 29 November（T3）.Spike development was observed with a stereomicroscope from seedling emergence until completion of anther differentiation,and the effects of temperature on spike differentiation were studied. The mean temperature and accumulated temperature above zero tended to be higher in the glasshouse than in the field during the whole growth period.Wheat plants underwent normal spike differentiation and attained maturity in the glasshouse,but the duration of the spike differentiation process was significantly shorter in the glasshouse than in the field（P〈0.01）.Therefore,the entire growth period was also shorter in the glasshouse than in the field.The spike differentiation process was accelerated with increasing temperature and accumulated temperature above zero.Compared with the field environment,the spike differentiation stages of significantly shorter duration in the glasshouse were early developmental stages from seedling emergence to the spike elongation,single ridge and double ridge stages.In the glasshouse,with the sowing time delayed（T2 and T3）,the duration of spike differentiation was shortened,the onset of each spike differentiation stage was delayed,and the accumulated temperature during the entire spike differentiation period was lower.The duration of spike differentiation under the T1 treatment was significantly longer than that under the T2 treatment（P〈0.01）. Differences in spike differentiation between the two cultivars were apparent.In this study,the duration of spike differentiation was shorter,and the onset of each developmental stage was earlier,in Zhengmai 9023 compared with those of Zhoumai 18.The effects of temperature on spike differentiation differed between the cultivars.The accumulated temperature during spike differentiation for Zhengmai 9023 was lower than that of Zhoumai 18 sown at the same time.For Zhengmai 9023,high temperature mostly influenced the intermediate developmental stages,namely the double ridge,glume differentiation,and floret differentiation stages.For Zhoumai 18,early and late developmental stages were mainly affected by high temperature,namely the single ridge,double ridge and anther differentiation stages.The influence of accumulated temperature was strongest on the glume differentiation stage in Zhengmai 9023,and on the anther differentiation and double ridge stages in Zhoumai 18.