土壤水分对冬小麦初生根、次生根生长发育的影响

１９９３－１９９４年冬小麦管栽水分试验结果表明，初生根与次生根生长量，数量及分枝能力基本与土体水量呈正相关，胁迫程度愈深，受抑程度愈大。初生根特别是一，二次根及其分枝数具有很强抗逆逆能力，水量愈大，三，四次根数愈多。次生根尤其是其数量对土水环境极为敏感。当土壤含水量你于田间持水量６０％时，受到严重抑制，胁迫后复水，使初生根三次根数量增加，根系活性延长对次生根的激励作用更大。前期胁迫愈严重，促进效果

Effect of Soil Water on Growth and Development of Primary and Adventitious Root of Winter Wheat

The pot experiment of winter wheat with seven soil water treatments were conducted at the experiment area of China Agricultural University in 1993 and 1994. The results indicated that the higher ability of stress resistance of primary roots compared with adventitious roots was dependent largely on the relative constant of their main and first lateral roots, the high er soil water content was, the larger amount of the second and third lateral roots development but the greater their death rate were also after flowering stage. Regulation of root by water was mainly rely on the effect on adventitious root because of its higher sensitivity to soil water. Pri mary root was thin and longer, of which function was important for winter wheat throughout its whole life, especially prewinter stage. Most function was undertaken by adventitious root after booting stage. Adventitious root was inhibited severely at once soil water was below 60% of field capacity. Compensative growth increased in amount of the second lateral roots and decreased in the rate of root death was evident for root system, especially adventitious root, after removing water stress. The appropriate time for regulation of root was jointing to booting stage. The limi tation of water stress wasn't allowed below 60% of field capacity.