根系伸展范围对小麦、油菜耐缺锰能力的影响

Effect of Root Extension on the Tolerances of Wheat and Oilseed Rape to Mn Deficiency

在水旱轮作的缺锰土壤上,采用耐缺锰能力具有明显差异的两个小麦品种和两个油菜品系,通过限制植株根系下扎的田间网袋试验方法研究了根系伸展范围与小麦、油菜耐缺锰能力的关系。试验结果表明,将植株根系限制在耕作层导致小麦出现典型的缺锰症,分蘖减少,减产严重。同小麦相比,油菜所受的影响较小,两个品系油菜全生育期均未出现缺锰症,减产幅度也比小麦轻得多。这一结果说明,小麦的耐缺锰能力在很大程度上取决于对中下部土层淀积锰的吸收利用能力,即与根系伸展范围有非常密切的关系;而限制根系下扎对油菜的锰营养状况影响相对较小,即根系伸展范围的差异并不是油菜耐缺锰能力明显高于小麦的主要原因。

Mn-deficient soil of rice-wheat rotation,the relationship between root extension and the tolerance of wheat and oilseed rape to Mn deficiency was studied by a method of field ny- lon-net which could limit root extension.The results indicated that limiting root in plow layer resulted in typical Mn-deficient symptoms and great decrease of tillers and grain yield in wheat.Compared with wheat,root limitation had less effect on the growth of oilseed rape.Two oilseed rape lines had no obvious symptoms in all growing time even grown in nylon-net and showed higher relative grain yield than two wheat cultivars.So it is suggested that tolerant abilities of different wheat genotypes to Mn deficiency were closely related to root extension, but the difference in tolerance to Mn deficiency between wheat and oilseed rape did not come from the difference of root extension.