外源6-BA对孕穗期低温胁迫后小麦旗叶生理、产量及品质的影响

Effects of exogenous 6-BA on flag leaf physiology,yield,and quality of wheat after low temperature stress at booting stage

春季低温通常发生在冬小麦孕穗期,导致小麦大幅减产。本研究选用低温反应敏感型小麦品种‘皖麦52’和低温反应迟钝型小麦品种‘烟农19’作为试验材料,在孕穗期将小麦盆栽置于人工气候室内进行低温处理(-2和0℃),低温处理结束后分别喷施浓度为10、20、30 mg·L^(-1)的6-苄氨基腺嘌呤(6-BA)溶液,以喷施等量蒸馏水作为对照,探讨孕穗期低温胁迫后喷施6-BA对小麦旗叶部分生理特性、产量和品质的影响。结果表明:与对照相比,外源喷施6-BA处理的小麦幼穗形态较为饱满,小花形态得到改善,穗下节间维管束数目增加;6-BA促进了小麦旗叶可溶性糖、可溶性蛋白和脯氨酸的积累;过氧化物酶和超氧化物歧化酶活性提高,丙二醛含量降低。外源喷施6-BA后小麦退化穗数减少,穗粒数和千粒重提高,籽粒蛋白质、湿面筋含量和沉降值增加。综上,外源喷施6-BA可以有效缓解低温胁迫对小麦旗叶和产量造成的影响。在本试验条件下,喷施6-BA溶液对烟农19的缓解效果要高于皖麦52,其中以喷施20 mg·L^(-1)的6-BA溶液对低温胁迫的缓解效果最好。

Low temperature(LT)in spring usually occurs at the booting of winter wheat,resulting in reduction of wheat yield.In this study,we used the LT-sensitive wheat cultivar‘Wanmai 52'and the LT-insensitive wheat cultivar‘Yannong 19'as experimental materials to conduct LT treatment(-2℃ and 0℃)at booting stage.After the LT treatment,we sprayed 6-benzylaminoadenine(6-BA)solutions with concentrations of 10,20,and 30 mg·L^(-1)respectively,with equal mass distilled water as control to investigate the effects of spraying 6-BA on the physiological characteristics,yield and quality of wheat flag leaves after LT stress at booting stage.The results showed that compared with the control,young ear of wheat treated with exogenous spraying 6-BA was fuller,the floret morphology was improved,and the number of vascular bundles under the spike was increased.6-BA application promoted the accumulation of soluble sugar,soluble protein,and proline in flag leaves.The activities of peroxidase and superoxide dismutase were increased,and the content of malondialdehyde was decreased.Exogenous 6-BA application decreased the number of degenerated spikes of wheat,increased the number of grains per spike and 1000-grain weight,as well as the contents of grain protein,wet gluten,and sedimentation value.In summary,exogenous 6-BA application could effectively alleviate the effects of LT stress on flag leaf and yield of wheat.Under the conditions of this experiment,the mitigation effect of spraying 6-BA solution on Yannong 19 was higher than that of Wanmai 52,and the mitigation effect of spraying 20 mg·L^(-1)6-BA solution on low temperature stress was the best.