PEG胁迫下西北不同蚕豆种子萌发期的抗旱性鉴定

Drought Tolerance of Different Fava Beans During the Germination Stage under PEG Stress in the Northwest China

【目的】利用PEG-6000胁迫对8份蚕豆品种的种子萌发、幼苗发根力和抗旱能力进行研究,为蚕豆抗旱种质资源鉴定评价及品种选育提供理论依据。【方法】采用不同渗透势:-0.09、-0.24、-0.43、-0.66、-0.85、-1.20MPa的PEG-6000溶液(质量分数为5%、10%、15%、20%、25%、30%)模拟干旱胁迫测定种子萌发指标,分析其变化规律。【结果】随着PEG-6000质量分数的增加,蚕豆种子的发芽率、发芽势、发芽指数、胚根长、胚芽干重总体呈下降趋势,低浓度的PEG胁迫对部分蚕豆品种种子萌发有一定的促进作用;随着胁迫程度的加剧,蚕豆种子的发芽率、发芽势、发芽指数显著降低,胚芽和胚根的生长受到抑制。【结论】15%PEG-6000浓度为合适的模拟干旱胁迫条件,PEG-6000质量分数越大,对蚕豆种子萌发和幼苗发根力的抑制作用越强。经隶属函数法分析蚕豆种子萌发期抗旱性强弱依次为:青海13号>尕大豆>临蚕9号>马牙>青蚕15号>临蚕6号>青海12号>青蚕14号。

【Objective】This study was carried out to explore the effects of Polyethylene glycol（PEG-6000）stress on seed germination,seeding root ability and drought resistance condition of eight cultivars of fava bean.【Method】Different osmotic potential of PEG-6000（-0.09,-0.24,-0.43,-0.66,-0.85and-1.20 MPa）were used to simulate drought stress.The indicators of seed germination were measured and change rules were analyzed.【Results】With the increase of PEG-6000 concentration,the germination rate,germination vigor,germination index,growth of plumule and germ dry weight of the fava bean seeds decreased generally.Low concentration of PEG improved seed germination of some fava bean variety materials.As the drought intensified,seed germination rate,germination vigor and germination index decreased and the growth of plumule and radical were inhibited.【Conclusion】The suitable PEG-6000 concentration for drought resistance identification was 15%.The larger PEG-6000 concentration was,the more severely the seed germination and seeding root ability of fava bean were influenced.The comprehensive evaluation on drought resistance of fava bean according to subordination function method indicated thatthe drought resistance ability were ranked as Qinghai 13 Gadadou Lincan 9 Maya Qingcan 15 Lincan 6 Qinghai 12 Qingcan 14.