PEG模拟干旱胁迫处理对青稞幼苗生长和生理特性的影响

Impact of Drought Stress Induced by Polyethylene Glycol on the Growth and Physiological Characteristics of Hulless Barley Seedlings

为选育具有抗旱性的青稞品种及明晰其抗旱机制,以819份青稞品系(种)为材料,通过PEG模拟干旱胁迫,重点考察青稞种子的发芽率、株高、地上生长量、地下生长量、地上鲜干质量、地下鲜干质量等形态指标以及在胁迫环境下不同抗性材料的生理特性变化。结果表明:在21%质量分数的PEG 6000溶液胁迫处理下,不同青稞品系(种)的生长和生理特性具有显著性差异(P<0.05)。筛选出具耐旱特性的品系(种)15份:喜拉16、ZDM4372、ZDM4581、ZDM4312、ZDM4412、ZDM4521、ZDM4516、喜拉3号、ZDM4456、WDM01467、ZDM4568、ZDM4572、ZDM4267、ZDM4530、藏0559;对干旱敏感的材料15份:ZDM4279、ZDM4505、WDM04080、ZDM4401、迪庆黑元桂、藏1312、ZDM4367、ZDM4381、ZDM4397、ZDM4409、ZDM4445、北青1号、WDM00787、藏0976、2010区04。经过PEG 6000胁迫处理后,具有抗旱性的喜拉16号等材料的生长量要显著优于旱敏感材料,而胁迫处理后旱敏感材料体内的丙二醛(MDA)有显著的积累;过氧化物酶(POD)在受胁迫后,其含量均要高于对照组材料;过氧化氢酶(CAT)在经过胁迫处理后,在旱敏感材料中的含量要显著低于对照组材料,而在抗旱材料中则具有显著积累。

To lay foundations for breeding hull-less barley varieties(lines) with drought tolerance and to clarify the mechanisms underlying their drought tolerance, this study determined the impact of drought stress induced by polyethylene glycol 6000(PEG 6000)on the growth and development of hull-less barley varieties(lines). A total of 819 materials of hull-less barley varieties(lines) were evaluated for various growth parameters(seed germination rate, plant height, aboveground biomass, underground biomass,aboveground fresh and dry weights, and underground fresh and dry weights) under PEG 6000-induced drought stress. Fifteen of them were identified as drought-tolerant varieties, comprising Xila16, ZDM4372, ZDM4581, ZDM4312, ZDM4412, ZDM4521, ZDM4516,Xila3, ZDM4456, WDM01467, ZDM4568, ZDM4572, ZDM4267, ZDM4530, and Zang0559. Another 15 were identified as drought-sensitive varieties, consisting of ZDM4279, ZDM4505, WDM04080, ZDM4401, diqingheiyuangui, Zang1312, ZDM4367,ZDM4381, ZDM4397, ZDM4409, ZDM4445, Beiqing1, WDM00787, Zang0976, and 2010 District 04. Under the treatment with 20%PEG 6000, drought-tolerant varieties such as Xila16 showed significantly(P < 0.05) higher values in growth parameters than drought-sensitive varieties. These 30 varieties were selected for the experiment to determine their contents of malondialdehyde(MDA),peroxidase(POD), and catalase(CAT). MDA accumulation was remarkable in drought-sensitive varieties under the stress. POD content was significantly higher in the treatment with PEG 6000 than in the non-treated control. Under the PEG 6000-induced drought stress, CAT content significantly rose in drought-tolerant varieties, but significantly declined in drought-sensitive varieties in comparison with the control.