SORGHUM ROOT-GROWTH AND WATER-USE AS AFFECTED BY WATER-SUPPLY AND GROWTH DURATION
SORGHUM ROOT-GROWTH AND WATER-USE AS AFFECTED BY WATER-SUPPLY AND GROWTH DURATION
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DOI：
10.1016/0378-4290(84)90019-4
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发表时间：
1984-01-01
影响因子：
5.8
通讯作者：
ARKIN, GF
中科院分区：
文献类型：
--
作者：
BLUM, A;ARKIN, GF
1976年在美国德克萨斯州坦普尔的根部观测场中种植了高粱早(‘58M’)和晚(‘90M’)等基因系，研究了土壤水分和生育期对高粱根系发育和植株水分利用的影响。该装置由填土的钢室组成，装有玻璃板，安装在地面的挡土结构中。每个房间都被抬出地面，用来称重和测量玻璃面板上可见的根部。在所有的小室里，土壤在种植前都被灌溉到田地的容量。然后实施了两种土壤水分制度：灌溉处理，只要土壤水分含量降至土壤有效水的50%，就进行灌溉；胁迫处理，不进行灌溉，植物在储存的土壤水分上生长。相对于两个基因型各自的叶面积，早熟品种的蒸腾作用显著低于晚熟品种。只要土壤水分占土壤有效水的20%，就可以在没有明显植物胁迫的情况下满足蒸腾需求。在土壤有效水分的20%以下，蒸腾作用主要受叶片衰老过程中叶面积减少的控制。晚熟品种的累计单株根长和根长密度大于早熟品种，单位叶面积的根长密度小于早熟品种。在土壤水分胁迫条件下，单位绿叶面积的根长密度增加，主要是由于绿叶面积的减少。在灌溉条件下，根系沿土壤剖面的分布高度偏斜(浅层根系密度高于深层)，不灌溉条件下根系分布更加均匀。灌溉促进了土壤浅层根系的生长。Apprx的根死亡率。抽穗产生的累积根长的2/3被记录下来。根的死亡率不仅与植株的总衰老有关，还与植株的年龄和生根深度有关。
Early (''58M'') and late (''90M'') isogenic lines of sorghum were grown in a root observation field installation at Temple, Texas [USA] in 1976, to study the effect of soil moisture and growth duration on root development and plant water-use. The installation consisted of soil-filled steel chambers equipped with a glass panel and installed in retaining structures in the ground. Each chamber was lifted out of the ground for weighing and measuring roots visible on the glass panel. In all chambers, soil was irrigated to field capacity prior to planting. Two soil moisture regimes were then imposed: an irrigated treatment, wherein irrigation was applied whenever soil moisture content was reduced to 50% of available soil water; and a stress treatment, wherein no irrigation was applied and plants grew on stored soil moisture. Transpiration was considerably less for the early than for the late genotype in relation to the respective leaf area of the 2 genotypes. Transpiration demand was met without apparent plant stress, as long as the soil moisture content of the total soil volume was > 20% of available soil water. Below 20% of available soil water, transpiration was controlled mainly by a reudction in leaf area through leaf senescence. Total cumulative root length per plant and root length density were larger and root length density per unit leaf area was smaller for the late than for the early genotype. Root length density per unit of green leaf area increased under conditions of soil moisture stress due mainly to the reduction in green leaf area. Root distribution along the soil profile was highly skewed (higher root concentration at shallow than at deep soil layers) with irrigation and more homogeneous without irrigation. Root growth at shallow soil layers was promoted by irrigation. Root mortality of .apprx. 2/3 of the total cumulative root length produced by heading was recorded. Root mortality was not only associated with total plant senescence, but with plant age and rooting depth.