不同供磷水平小麦苗期根系特征与其相对产量的关系

研究了缺磷条件下不同基因型小麦苗期根系形态学及生理学适应特征 ,结果表明 :在缺磷环境中 ,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是显著提高。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是显著的 ,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之间是显著的 ,表明侧根性状主要是受环境因素控制的。对 6种基因型小麦的研究表明 ,高磷水平的小麦种子根的生长角度明显低于低磷处理的小麦 ,根角之间存在着显著的基因型差异。在缺磷条件下 ,6种基因型小麦完整根系分泌的酸性磷酸酶活性、根轴数量、根轴长度、根生长角度和根系长度之间均存在着显著的基因型差异。相关分析表明 ,缺磷条件下的小麦苗期根系形态指标和根系分泌的酸性磷酸酶活性的交互作用与小麦的相对产量之间具有显著的线性关系 ,这种关系说明以上 5种性状均可作为早期有效地筛选磷高效小麦品种的指标

Characteristics of Root System of Wheat Seedlings and Their Relative Grain Yield

The variation in morphology and physiology of root systems of wheat genotypes under phosphorus deficiency are very important in practice.The objectives of this study were to determine the early indicators related to phosphorus efficiency and establish a new method of fast and effectively selecting high phosphorus efficiency wheat genotypes.The results showed that the number of root axes and the length of lateral root of P deficient plant were significantly lower(P<0 05) than P sufficient plant;The partitioning of assimilates to root was greater than to shoot at low P supply.The length of root axis and root system and the number of lateral roots were sharply increased under low P stress.The differences in number and length of root axis of the given wheat genotypes between the same or different levels of phosphorus supply were significant(P<0 05).This suggests that the two traits are 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 shows that the traits of lateral root mainly depend on external factors.The differences in root number and root length,and axis length,root angle and activity of acid phosphatase exuded by roots among 6 wheat genotypes were significant(P<0 05).The linear relationships between relative grain yield and the interaction of the morphological and physiological traits were significant.This suggests that the five traits can be used as indicators of selecting high P efficiency wheat varieties.