| In order to explore the suitable plant row configuration and planting density of winter wheat,the winter wheat cultivars of Xindong 22 and Xindong 50,which were widely cultivated in southern Xinjiang,were selected as materials,five different planting densities were adopted,under the condition uniform planting(the same spacing between plants and rows),and the soil was sampled at five layers with a root drill at the overwintering stage,jointing stage,heading stage and maturity stage.Root indexes were analyzed by Win RHIZO root analysis software.The following results were as follows:Under the condition of uniform planting of winter wheat root system growth trend is along with the birth process root length density,root surface area,root volume,root diameter were reached a peak at the heading stage,root dry weight density peak in jointing stage,root in the soil of top-down vertical descending,upper-middle-class root diameter larger lower root diameter smaller.Under the condition of uniform planting,the roots of winter wheat were mainly distributed in the 0-40 cm soil depth,especially in the 0-20 cm soil depth.The depth of the 60-100 cm soil layer increased with the growth process,and decreased after reaching the maximum at the heading stage.With the same planting density of 2.04 million plants/hm~2,the root spatial and temporal distribution of multi-ear and large-ear cultivars under uniform planting was different.The root length density and root surface area of multi-panicle type were larger than those of large-panicle type.The root diameter of 0-100 cm multi-panicle cultivars was smaller than that of large-panicle cultivars,and the root surface area of 20-100 cm multi-panicle cultivars was larger than that of large-panicle cultivars.The root dry mass density of the two cultivars showed opposite development curves.The root dry mass density of the multi-panicle type increased with the growth process,while the root dry mass density of the large-panicle type increased first and then decreased with the growth process.The multi-panicle type had better root growth in the60-100 cm deep soil layer.Under the same density and different plant row spacing,smaller plant row spacing was beneficial to root growth in the overwintering stage,while larger plant spacing and smaller row spacing were beneficial to root growth in the jointing and heading stage of winter wheat.The root growth and development of the large-ear type was better than that of the multi-ear type.At the same time,due to the large population in the jointing stage,the multi-ear type had different degrees of lodging at the heading stage in the experiment,which was unfavorable to the production.No lodging occurred in the large-ear type.In this experiment,the overwintering period had little effect on the winter wheat root system,indicating that the overwintering period was not the key period to determine the wheat yield,but the jointing stage and heading stage were the most vigorous period for the winter wheat root system growth,and the center of winter wheat root system growth was gradually moving down.At the late heading stage of winter wheat,the root system of the upper layer began to decay,but the root system of the lower layer still grew to a certain extent until the maturity stage.With the decrease of planting density,root length density,root dry weight and root surface area of winter wheat increased,and reached the highest value at heading,but the decreasing rate of root length density per plant after heading accelerated with the increase of planting density.Root indexes increased first and then decreased with the development of wheat growth.In terms of yield composition,the number of effective panicles increased with the increase of density,However,the grain number per spike and grain weight showed a strict decreasing trend with the decrease of density... |
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