红土旱地冬小麦根系生长动态观测

Dynamic Observation of Root System Development of Winter Wheet in Red Rainfed Lands

冬小麦根系的生长发育可概括为根系的形成、壮大和逐渐衰亡三个阶段。初生根对根系乃至小麦的整体生育具有奠基作用。其发根条数与单株成穗的相关系数为０．９６６８；次生根条数与穗粒数的相关系数为０．９７２９。不同根序长度差距甚大，其增长速度依次是早发根＞后发根。根系在土层中基本呈伞状分布。在保持土壤原结构条件下，采用小型土传统体隔离分期完整出坑冲洗的取样方法，能够更清楚地观测各生育期根系的全貌。

The growht and development of root system of winter wheat was final-ized into three stages-the formation,development and gradual death of root systemthrough 6 years tests and observations.The initial root played the foundamental role inthe complete development of winter wheat root system.The correlation coefficient be-tween the number of initial roots and the ear number per plant was 0.9668,while thecorrelation coefficient between the number of secondary roots and the grain number perear was 0.8729.The length gap of different modal roots was so signifieantly differentthat the increasing rate of early emerging roots was greater than that of late emergingones.The root system distribution was the umbrella shape in soil.The complete statusof plant root system growth can be observed clearly using the sampling procedure-arti-ficial small colums separated from the original soil completely and washed with water indifferent stages.