不同外源物质对盐、碱及干旱胁迫下草木樨种子萌发、幼苗生长及生理的影响

为筛选出促进盐、碱及干旱胁迫下草木樨种子萌发和幼苗生长的最佳外源物质及其处理浓度,采用培养皿滤纸发芽法,研究不同浓度赤霉素(GA)和褪黑素(MT)浸种6 h对盐、碱及干旱胁迫下草木樨种子萌发及幼苗生长的影响。结果表明,盐胁迫下,200 mg·L^(-1)的GA是促进种子萌发的最佳处理,50μmol·L^(-1)的MT是提高幼苗超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的最佳处理。在碱胁迫下,200μmol·L^(-1)的MT则使幼苗胚轴长出现最大值。在干旱胁迫下,100 mg·L^(-1)的GA使草木樨种子发芽率和胚根长出现最大值。隶属函数综合评价得出,缓解盐胁迫的最佳外源物质是GA,最佳处理浓度是200 mg·L^(-1),缓解碱和干旱胁迫的最佳外源物质是MT,最佳处理浓度分别是50和100μmol·L^(-1)。综上所述,MT和GA浸种能够在盐、碱及干旱胁迫下促进草木樨种子萌发和幼苗生长,研究结果可为提高草木樨对盐、碱及干旱胁迫的耐受能力提供参考。

Analysis on Maize EST Database under the Co-stress of Drought,Salt and Alkali

[Objective] The research aimed to construct maize cDNA library under the co-stress of drought,salt and alkali,and initially analyze the expression of gene which related to the cellular function.[Method] The total RNA of mixed tissue（leaf,stem and blossom bud） of maize YQ7-96 in the male and female differentiation period（12-leaf age） was extracted.By using SMART technology,cDNA library of pDNR-LIB vector was constructed.BlastX contrast and MIPS classification analysis of EST sequence were carried out by randomly picking the clone.[Result] 3 027 cDNA clones were picked out to sequence.The length of 94.45% EST was bigger than 400 bp,and 1 861 single gene clusters were obtained.The gene which maintained the normal physiological activity occupied 65.36%.The genes which involved in the intracellular transportation,signal transduction,cell defense and cycle,DNA metabolic process were respectively 9.26%,6.58%,2.63% and 3.16%.[Conclusion] Based on the successful construction of maize cDNA library under the co-stress of drought,salt and alkali,EST was sequenced,analyzed and classified.EST which related to the cellular function was screened.It laid the foundation for the following research.