摘要
为探究杂交狼尾草与美洲狼尾草的抗旱性能差异,在种子萌发期采用PEG-6000模拟不同干旱胁迫梯度(0 Mpa、-0.1 Mpa、-0.3 Mpa、-0.5 Mpa、-0.7 Mpa),并测定其发芽势、发芽率、发芽指数、根芽比等7项指标;在幼苗生长期利用盆栽控水法,设置4个水分梯度(田间持水量为80%、60%、45%、35%)对其过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛(MDA)、脯氨酸(Pro)、可溶性糖(SS)进行测定,并利用隶属函数法综合评价2种狼尾草属牧草抗旱性强弱。结果表明:干旱胁迫可明显抑制2种狼尾草属牧草种子的萌发,在-0.7 Mpa梯度时2种狼尾草属牧草的发芽势、发芽率和发芽指数均降至最低,其中发芽率分别较对照降低34.0%和17.4%。随着干旱胁迫程度加深,2种狼尾草属牧草的根芽比均显著上升并在-0.7 Mpa梯度时达到峰值(P<0.05),分别较对照提高1.19%和2.08%。在幼苗生长期随着干旱胁迫程度的加深,杂交狼尾草幼苗3种酶活性、SS含量、Pro含量均显著上升(P<0.05),美洲狼尾草幼苗SOD、POD酶活性和SS含量显著上升(P<0.05),CAT酶活性先升后降,Pro含量无显著变化。综上,干旱胁迫下2种狼尾草属牧草优先增加胚根长度,增强从环境中吸水能力,并通过提高3种酶活性,产生Pro和SS降低体内的损伤。基于13个指标利用综合隶属函数分析法得到:美洲狼尾草的抗旱性强于杂交狼尾草。
This study aimed to explore the differences in drought resistance between Pennisetum america⁃num×P.purpureum and Pennisetum americanum.During seed germination,various drought stress levels(0 Mpa,−0.1 Mpa,−0.3 Mpa,−0.5 Mpa,−0.7 Mpa)were simulated using different concentrations of PEG-6000.Seed germination indices,including germination potential,germination percentage,germination index,radicle-germ ratio,and other index were measured.During seedling growth stage,the experiment used the potted water control method with four different water levels(80%,60%,45%,and 35%of field capacity).The activities of peroxidase(POD),superoxide dismutase(SOD),catalase(CAT),and contents of malondialdehyde(MDA),proline(Pro),and soluble sugar(SS)were measured.Subsequently,the drought resistance of the two Pennisetums species was evaluated using the membership function.The results showed that drought stress had a significant inhibition effect on the germination of seeds of the two species.The germination potential,germination percentage,and germination index of both species were found to be the lowest under−0.7 Mpa drought stress conditions,with the germination percentage reduced by 34%and 17.4%compared to the control group(0 Mpa),respectively.As the drought stress increased,the radicle-germ ratio of both species significantly increased,reaching the maximum value under−0.7 Mpa drought stress(P<0.05),with an increase of 1.19%and 2.08%,respectively,compared to the control group.During the seedling growth period,the activities of SOD,POD,and CAT,as well as the contents of SS and Pro in P.americanum×P.purpureum seedlings,significantly increased(P<0.05)with the drought stress deepened.However,the activities of SOD and POD,along with the SS content of P.americanum seedlings,increased with deteriorating drought stress(P<0.05),while CAT activity initially increased and subsequently decreased,with no significant change in Pro content.In conclusion,under drought stress,both Pennisetums species exhibited preferential growth in radicle length and enhanced water uptake from the environment,reducing in vivo damage by increasing the activities of three enzymes and producing large amounts of proline and soluble sugar.The combination of thirteen indexes with the membership function analysis indicated that the drought resistance of P.americanum was stronger than that of P.americanum×P.purpureum.
作者
周洁仪
赵文武
杨杨
谢文辉
赵丽丽
ZHOU Jieyi;ZHAO Wenwu;YANG Yang;XIE Wenhui;ZHAO Lili(College of Animal Science,Guizhou University,Guiyang 550025,China)
出处
《中国草地学报》
CSCD
北大核心
2023年第8期50-59,共10页
Chinese Journal of Grassland
基金
贵州省科技计划项目(黔科合平台人才[2021]5636号
黔科合支撑[2021]一般155)
国家自然科学基金(32060391)。
关键词
杂交狼尾草
萌发期
苗期
隶属函数
抗旱性
Pennisetum
Germination stage
Seedling stage
Membership function
Drought resistance
