渍水和增温对小麦根系形态、生理和地上部物质积累的影响

Effects of waterlogging and increasing temperature on the morphology of roots,physiology and above-ground matter accumulation of wheat

[目的]本文旨在明确花后渍水和增温对小麦根系形态和干物质转运的影响。[方法]以‘扬麦18’和‘烟农19’为试验材料,采用盆栽试验方法,在小麦开花期设置渍水(WL,花后0~7 d全天淹水深为2 cm)、增温(HL,花后0~7 d每日10:00—16:00处理)、渍水+增温复合因素(WL+HL)与对照(CK,不进行渍水和增温)4个处理,于开花期及开花后每7 d取样,测定其根系长度、平均直径、体积、干重、SOD活性、POD活性、MDA含量、O_(2)^(·-)产生速率以及干物质积累与转运和产量。[结果]在花后7 d时,WL的‘扬麦18’的根系总长度、平均直径、体积以及干重均增加,‘烟农19’的根系总长度、平均直径以及干重均降低。花后14~28 d WL和HL处理中,2个小麦品种的根系总长度、体积以及干重均降低。WL对根系形态指标的影响大于HL,WL+HL对其根系形态指标影响程度大于WL和HL单一因素处理。WL和HL降低了2个小麦品种SOD活性,提高了2个小麦品种POD活性、MDA含量以及O_(2)^(·-)产生速率。WL+HL对SOD活性、POD活性、MDA含量以及O_(2)^(·-)产生速率影响最大。逆境处理花前干物质转运量、转运率及对籽粒产量贡献率提高;但花后干物质积累量及对籽粒产量贡献率降低,WL+HL的影响最大。相关性分析显示根系形态指标与产量存在正相关性,其中根系长度与‘扬麦18’产量关系呈正相关,根系体积和干重与‘烟农19’产量关系呈正相关,MDA含量和POD活性及O_(2)^(·-)产生速率对产量的影响显著,SOD活性对其产量影响不显著。方差分析结果显示,渍水对根系形态指标的影响达到显著水平,增温对根系形态指标的影响不显著,渍水和增温对MDA含量、POD活性、O_(2)^(·-)产生速率的影响均呈显著负相关。[结论]逆境处理限制了根系的生长,对不同品种的根系形态指标影响存在差异;WL对根系的影响大于HL,但地上部干物质转运与之相反,HL对其影响大于WL;与对照相比,WL+HL对植株地上、地下部的伤害均最大。

[Objective]This paper aimed to clarify the effects of post-anthesis waterlogging and warming on root morphology and dry matter transport in wheat.[Method]With‘Yangmai 18’and‘Yannong 19’as test materials,the pot experiment method was used.During the anthesis stage of wheat,waterlogging(WL,0-7 days after anthesis,the depth of flooding was 2 cm all day),and the temperature increased(HL,10:00-16:00 treatment every day from 0 to 7 days after anthesis),waterlogging+warming compound factor(WL+HL)and control(CK,no waterlogging and warming)4 treatments stresses were imposed to wheat plants separately.Samples were taken at anthesis stage and every 7 days after anthesis to determine root length,average diameter,volume,dry weight,SOD activity,POD activity,MDA content,O_(2)^(·-)production rate,and dry matter accumulation and transport and yield.[Result]The total root length,average diameter,volume and dry weight of‘Yangmai 18’increased,while the total root length,average diameter and dry weight of‘Yannong 19’decreased in WL treatment at 7 d after anthesis.The total root length,volume and dry weight of the two wheat varieties decreased in WL and HL treatments at 14-28 days after anthesis.The influence of WL on root morphological indexes was greater than that of HL,and the influence of WL+HL on root morphological indexes was greater than those of WL and HL alone.WL and HL decreased SOD activity of two wheat varieties,but increased POD activity,MDA content and O_(2)^(·-)production rate of two wheat varieties.WL+HL had the greatest effect on SOD activity,POD activity,MDA content and O_(2)^(·-)production rute.The dry matter transport amount,transport rate and contribution rate to grain yield before anthesis increased in the stress treatment;however,the dry matter accumulation amount and the contribution rate to grain yield decreased after anthesis,and the WL+HL treatment had the greatest impact.Correlation analysis showed that there was a positive correlation between root morphological indicators and yield,among which root length was positively correlated with yield of‘Yangmai 18’,root volume and dry weight were positively correlated with yield of‘Yannong 19’,MDA content,POD activity and O_(2)^(·-)production rate had a significant effect on yield,but SOD activity had no significant effect on yield.The results of variance analysis showed that the influence of waterlogging on root morphological indicators reached a significant level,while the effect of warming on root morphological indicators was not significant.[Conclusion]Adversity treatment restricted root growth,and had different effects on root morphological indicators of different varieties;WL treatment had a greater effect on root system than HL treatment,but the aboveground dry matter transport was opposite,and HL had a greater effect on it than WL;compared with the control,WL+HL treatment had the greatest damage to the above-ground and below-ground parts of the plant.