干旱胁迫对云南主栽马铃薯品种淀粉累积及产量构成的影响

Effects of Drought Stress on Starch Accumulation and Yield Composition of Main Potato Varieties in Yunnan

以云南主栽马铃薯品种合作88、青薯9号和丽薯6号为试材,以浇灌营养液为对照,浇灌浓度为2.5%、5.0%、7.5%和10.0%的PEG溶液,使土壤含水量分别为55%、45%、35%和25%,模拟轻度、中度和重度干旱条件,探究不同程度干旱条件下马铃薯块茎中淀粉积累量、淀粉合成关键酶活性以及产量构成因素的变化规律。结果表明,干旱胁迫下,马铃薯块茎总淀粉、直链和支链淀粉含量大体上呈降低趋势。不同程度干旱胁迫下马铃薯块茎淀粉合成关键酶活性变化趋势不同,主要受品种和干旱条件的影响。相关性分析表明,干旱胁迫下,AGPase和GBSS在合作88的淀粉组分合成中起重要作用,青薯9号的淀粉组分合成中AGPase、GBSS和SBE起重要作用,AGPase、GBSS、SBE和SSS均参与了丽薯6号淀粉组分的合成。产量构成分析表明,不同程度干旱胁迫对马铃薯品种之间产量构成的影响具有差异性,其中重度干旱胁迫对马铃薯的产量构成影响最大。

Taking the main potato varieties in Yunnan‘Hezuo 88’‘Qingshu No.9’and‘Lishu No.6’as test materials,and watering nutrient solution as the contrast,this experiment used watering PEG solution with concentrations of 2.5%,5.0%,7.5%and 10.0%,to make the soil water content as 55%,45%,35%and 25%,respectively,simulating mild,moderate and severe drought conditions;and studied the changing rule of starch accumulation amount in potato tubers under different degrees of drought conditions,activities of key enzymes in starch synthesis,and factors in yield component.The results showed that the total starch content in potato tubers,amylose and amylopectin contents by and large presented a reducing tendency under drought stress.Under varying degrees drought stress,key enzyme activities of potato tuber starch synthesis had different variation trend and were mainly affected by varieties and drought conditions.Correlation analysis showed that under drought stress,AGPase(glucose pyrophosphorylase)and GBSS(bound starch synthase)played a major role in synthesis of starch component in‘Hezuo 88’.While,AGPase,GBSS and SBE played an important role in synthesis of starch component in‘Qingshu No.9’.And AGPase,GBSS,SBE and SSS all took part in the synthesis of‘Lishu No.6’starch component composition.Yield components analysis showed that impacts brought about by different degrees drought stress on yield components had defference between potato varieties.Of which,severe drought stress had the greatest effect on potato yield composition.