花生和玉米前茬根系分泌物对冬小麦幼苗生长及抗旱性的影响

Effects of root exudates from peanut and maize on growth and drought resistance of winter wheat seedlings

为探明花生和玉米根系分泌物对小麦幼苗生长的化感作用,通过室内盆栽模拟茬口种植,研究了花生和玉米根系分泌物对冬小麦幼苗及根系生长、种子萌发过程及幼苗抗旱生理响应的影响。结果表明,相较于玉米茬口和清水对照,花生茬口可显著促进小麦幼苗地上及地下部分的生长,根冠比相较于对照提高了25.0%,根系总根长、根表面积、根投影面积、根体积分别较对照提高了43.8%、34.5%、37.1%、48.3%(P<0.05),而玉米茬口与清水对照之间各生长指标无显著差异。种子萌发试验表明,花生根系分泌物对冬小麦种子发芽率无显著影响,但显著提高了胚根长和胚根生长速率,化感指数较玉米分别增加了0.20和0.16。此外,在干旱胁迫前期,花生茬口处理下的小麦叶片相对含水量相对较高,而在干旱胁迫后期叶片相对电导率和MDA含量则显著低于玉米茬口。综合分析表明,花生茬口处理下,其根系分泌物能够促进冬小麦幼苗生长尤其是对根系发育有正向促进作用,同时可以提高小麦幼苗的抗旱性。

To explore the allelopathy of peanut and maize root exudates on wheat seedling growth,the effects of peanut and corn rhizosphere exudates on the winter wheat seedling and root system growth,seed germination process and physiological response of seedling to drought resistance were studied by simulating stubble cultivation in a pot experiment.The results showed that peanut stubble could significantly promote the growth of the ground and underground partsof wheat seedlings.Compared with the control,the root shoot ratio the total root length,root surface area,root projection area and root volume were increased by 25.0%,43.8%,34.5%,37.1%and 48.3%respectively(P<0.05).However there was no significant difference in growth indexes between maize stubble and no stubble control.Seed germination test showed that peanut root exudates had no significant effect on seed germination rate of winter wheat,but significantly increased radicle length and radicle growth rate.Compared with maize root exudates,peanut root exudates increased allelopathy index by 0.20 and 0.16,respectively.In addition,the relative water content of wheat leaves under peanut stubble treatment was relatively high in the early stage of drought stress,while the relative conductivity and MDA content of leaves were significantly lower than that of maize stubble in the late stage of drought.Comprehensive analysis showed that the root exudates of peanut stubble not only could promote the growth of winter wheat seedlings,especially the root development,but also improve the drought resistance of wheat seedlings.