缺磷胁迫下的小麦根系形态特征研究

研究了缺磷条件下不同基因型小麦（Triticum aestivum L.)苗期根系形态学适应特征，以明确环境因子对根系不同组分（根轴和侧根）生长发育调控作用的强度和根系形态与磷营养效率关系。在缺P环境中，小麦根轴数量和侧根长度明显减小，同化物向根部的分配比例增加，根轴长度、侧根数量和根系长度等均有显著提高。供试基因型小麦的根轴数量及其长度的差异在每个供磷水平及不同供磷水平之间均呈显著，说明这两种性状的差异是由基因型和环境因素共同决定的；而侧根特征的差异只在不同供磷水平间显著，表明侧根性状主要受环境因素的控制。对6种基因型小麦的研究表明，根轴数量、根轴长度、根生长角度和根系长度根角之间存在着显著的基因型差异。相关分析表明，小麦的相对产量与缺磷条件下的小麦苗期根系形态指标的交互作用之间具有显著的线性关系。这种关系说明根系形态性状可作为早期有效地筛选磷高效小麦品种的指标。

Morphology of wheat roots under low-phosphorus stress

The morphology of root systems of different wheat( Triticum aestivum L.) genotypes under low phosphorus stress were studied to determine the effects of external factors on components of root system and the early morphological indicators related to phosphorus efficiency. The number of root axes and the length of lateral root of P deficient plant were significantly lower than those of P sufficient plant. The length of root axis and root system,and the number of lateral roots were sharply increased under low P stress. The number and length of root axis were significantly different under different levels of phosphorus supply and among different wheat genotypes under same phosphorus supply. This implied that the two traits (number and length of root axis) were controlled by genotype and external factors. The difference in the characteristics of lateral root of the given wheat genotypes was significant only between different levels of P supply. It showed that the traits of lateral root mainly depended on external factors. The length and number of root axis, root length,and root angle were significantly different among 6 wheat genotypes. There exited significant linear relationships between relative grain yield and the interaction of the morphological traits,and it implied that the traits could be used as early indicators of selec ting high P efficiency wheat varieties.