稻秆还田深度对盆栽冬小麦结构和生理特性的影响

为了明确稻秆还田深度影响小麦生长发育的生理机制,采用盆栽试验研究了不同稻秆还田深度对小麦出苗、根系发育、根系结构、旗叶光合特性、旗叶SOD和CAT活性及胚乳细胞中淀粉体的影响。结果表明,(1)稻秆还田深度对小麦出苗率没有显著影响,但影响出苗整齐度;(2)15cm的稻秆还田深度能显著促进小麦根系生长,增加次生根数目,提高根冠比、根系总吸收面积、活性吸收面积及根系TTC还原强度;(3)不同稻秆还田深度对拔节期小麦次生根皮层结构影响不大,但对导管结构影响较大,还田深度越深,导管发育越慢;(4)15cm的稻秆还田深度能显著提高小麦旗叶叶绿素含量和光合速率,在生育后期能延缓旗叶叶绿素的降解速度,增加小麦产量;(5)15cm的稻秆还田深度能提高小麦生育后期旗叶中SOD和CAT的活性,延缓叶片的衰老;(6)15cm的稻秆还田深度能延缓小麦胚乳细胞中淀粉体发育时间。

Effects of the Depth of Returning Rice Straw into Field on the Structure and Physiological Characteristics of Winter Wheat Cultured in Pot

Pot Experiments were conducted to investigate the effects of the depth of returning rice straw into field on wheat seeding, root development, root structure, the chlorophyll contents and photosynthesis rate of flag leaves, SOD and CAT activities and amyloplast development in endosperm cells. The results were as follows: (1) The depth of returning rice straw into field had little impact on the rate of wheat seeding, but obvious effect on the degrees of seeding uniformity; (2) The 15 cm depth of returning rice straw into field could advance root growth, increase number of roots and enhance Root/Top ratio. Moreover, the total absorbing area, live absorbing area and TTC reducing capacity of roots were also improved accordingly; (3) The depth of returning rice straw into field had little impact on the root cortex, but obvious effect on the development of root vessel at jointing period; the deeper rice straw into field returned, the slower the vessel developed; (4) The 15 cm depth of returning rice straw into field could obviously improve the chlorophyll contents and photosynthesis rate of flag leaves, and slow the descent rates of chlorophyll in the later period of wheat growth and increase wheat yields; (5) The 15 cm depth of returning rice straw into field could increase the SOD and CAT activities in flag leaves and slow the leaves senescence; (6) The depth of 15 cm returning rice straw into field could slow the development of amyloplast in endosperm cells.