干旱胁迫下芝麻籽粒品质及抗氧化能力变化分析

Variation Analysis of Seed Quality and Antioxidant Capacity in Sesame under Drought Stress

为探明干旱胁迫下芝麻籽粒品质及抗氧化能力的变化规律,揭示芝麻对干旱胁迫的响应机制,采用盆栽控水处理方法进行干旱胁迫处理,分析了12个芝麻品种的产量,粒色,籽粒粗脂肪、蛋白质、芝麻素、芝麻林素、总酚含量以及抗氧化能力等性状指标。结果显示,干旱胁迫处理下,12个品种的株高、果轴长、单株蒴果数、单株产量4个性状均较对照(正常灌溉)降低,其中单株产量降幅为2.31%~51.22%;粒色ΔE值为0.96~3.30,粒色较对照加深;粗脂肪和粗蛋白含量较对照相比变幅分别为-0.72%~4.03%和-5.77%~4.12%。同时,受干旱胁迫影响,11个芝麻品种籽粒不饱和脂肪酸中亚油酸(18∶2)含量增加0.44%~9.05%,油酸(18∶1)含量降低0.16%~6.40%;与对照组相比,干旱胁迫下12个芝麻品种籽粒总酚含量变幅为-21.92%~33.00%,总抗氧化能力(FRAP值)变幅为-24.88%~73.92%。差异显著性分析表明,环境因素(干旱胁迫)对芝麻千粒质量、粗脂肪含量和FRAP值有显著影响,对芝麻林素和总酚含量有极显著影响。同时,芝麻林素和总酚含量与籽粒抗氧能力呈极显著正相关。综上,干旱胁迫导致芝麻产量下降,籽粒颜色加深,有利于芝麻中亚油酸(18∶2)含量的积累;干旱胁迫主要影响籽粒中芝麻林素和总酚含量的积累,推测籽粒中芝麻林素和总酚含量可作为芝麻抗旱能力的评价指标。

In this article,potted simulated drought environment treatment was applied to explore the variation of the quality and antioxidant capacity of sesame seed under drought stress to reveal its response mechanism.12 sesame varieties were collected to analyse the drought effect on seed yield,seed coat color,and content of oil,protein,sesamin,sesamolin,polyphenol and antioxidant capacity.The results showed that the plant height,capsule stem length,capsule number per plant and plant yield of 12 varieties under drought stress were lower than those of the control(normal irrigation),of which the plant yield decreased by 2.31%—51.22%.Meanwhile,theΔE value of seed color varied from 0.96 to 3.30,and the seed coat color got dark compared with control.The variation extents of oil content and protein content compared with control were from-0.72%to 4.03%and-5.77%to 4.12%,respectively.At the same time,the content of linoleic acid(18∶2)of 11 secame varieties seed increased by 0.44%—9.05%,and the content of oleic acid(18∶1)decreased by 0.16%—6.40%because of drought stress.The polyphenol content of 12 sesame varieties seed increased by-21.92%—33.00%,while FRAP(ferrous reduction power value)increased by-24.88%—73.92%compared with control.The effects of environmental factor(i.e.,drought stress)on sesame of thousand seed weight,oil content,FRAP value were significant,while its effects on sesamolin content and polyphenol content were evidently significant.Moreover,the significantly positive correlation between sesamolin content,polyphenol content and antioxidant capacity was found.In summary,drought stress led to lower sesame yield and deeper grain color compared with the control.Nevertheless,it was conducive to the accumulation of linoleic acid(18∶2)in sesame.Drought stress mainly affected the accumulation of sesamolin and polyphenol in sesame.So we suggest that the contents of sesamolin and polyphenol can be used as evaluation indexes for the drought resistance of sesame.