| As the main crop in North China Plain, winter wheat is affected by double influence--the monsoon climate and water resources. Therefore, drought is a major abiotic constraint in wheat production stress, while the mutual regulation between root and canopy is obvious on water use efficiency and water saving effect. Through the study of irrigation on root and crown characteristics and crop yield, the experiment will provide the necessary theoretical basis for the scientific irrigation. Using four treatments--W1, W2, W3and W4, we gain test data on Shannon20, acquired spikelet cultivar, and on Shannon21, large spike type cultivar. From the perspective of the whole plant, growth characteristics and crop yield were studied in winter wheat cultivars with different spike types. The results as follow:(1) Irrigation conditions affect the growth of canopy of winter wheat. Photosynthetic rate of flag leaf increased, while the soil moisture decreased. The stomatal conductance (Gs) sequence were W41> W3>W4> W3. Drought reduced intercellular CO2concentration (Ci) in wheat leaves. And effect on transpiration rate is not significant. The result show that drought can improve leaf water use efficiency, induce height, node length, stem weight and biomass and also affect obviously in plant height and stem fourth quarter.(2) Canopy growth is different between species. Plant height, node length, stem weight and canopy biomass of spikelet panicle type is less affected by drought, while leaf weight is more. And large panicle decline significantly under W4. Overall, spikelets variety is less than the big panicle in structural indicators. Under W4, the canopy fresh weight was significantly higher for spikelets varieties than for big spike cultivars in flowering and maturity stage.(3) Irrigation conditions affect root characteristics of winter wheat. Drought and excess W2will inhibit root biomass accumulation. W4significantly reduced root dry weight, but is conducive to deep root development in jointing stage. Water stress released, biomass increased. In the four water treatment, the root is majority located in0-10cm soil layer.(4) Root characteristics exists differences between varieties of winter wheat. The root of Shannon20is larger than Shannon21in drought treatments, and also deep root distribution is more. The result showed that spikelet variety has good drought resistance. Under suitable W2, big ear variety has more roots in20cm layer and the following layer.(5) Irrigation conditions affect the yield of winter wheat. Yield is W3> W4> W2> Wl under. The result illustrates that irrigation conditions affect the yield of winter wheat. Drought and W4made yield lower, and th e effects of drought is greater. Under drought treatment, the yield of spikelet variety is higher than big spike cultivar. This mainly related to more roots and more effective wheat.(6) Irrigation conditions affect root to shoot ratio of winter wheat. Throughout the growth period, root to shoot ratio basically maintained a downward trend. Root to shoot ratio under the big deal in arid than in watered. From jointing to booting stage, root to shoot ratio of Shannon20increased in W4treatment. Under suitable water treatment, root to shoot ratio of Shannon21pronounced obvious increasing trend.(7) Root to shoot ratio affect the relationship of root and shoot. The biomass of roots and canopy will significantly reduced, when root to shoot ratio is small in prophase and big in late stage. And this verify that the practice of early "Dunmiao" advantages. In prophase, the root to shoot ratio is large, and roots and canopy keeps competition in drought treatment. Under suitable water treatment, the roots and canopy promote each other, and root to shoot ratio is low.(8) Root-shoot ratio affect yield of winter wheat. The more differences of the Root shoot ratio between jointing and maturity, the higher the yield. Early root-shoot ratio relatively large, while post is small can improve the yield.The experiments show that irrigation and varieties affect root and shoot, also influent yield. In arid and semi-arid regions, spikelet variety-Shannon21has a relatively large structure and yield. It is more suitable for planting. Through measures to improve irrigation in root-shoot ratio can improve the yield of winter wheat. |
PDF Full Text Request