不同继代时间对“甘农3号”紫花苜蓿愈伤组织的影响

Effects of different subculture times on the callus of Medicago sativa L."Gannong No.3"

为确定紫花苜蓿愈伤组织继代的最佳时间,本试验以“甘农3号”紫花苜蓿(Medicago sativacv.Gannong No.3)无菌苗下胚轴为外植体诱导愈伤组织,对不同继代时间下愈伤组织褐化及抗氧化酶活性进行综合评价。结果表明,愈伤组织的褐化程度随继代时间的增加而增加,且继代时间越长,苯丙氨酸解氨酶(PAL)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性越强;继代时间为10 d时,紫花苜蓿愈伤组织褐化率最低,相比对照显著降低58.8%(P<0.05);继代时间为15 d时,愈伤组织褐化率比对照显著降低50.0%(P<0.05),丙二醛(MDA)含量、PAL、POD和CAT活性均显著低于对照(P<0.05),且与继代10 d相比,差异均不显著(P>0.05)。因此,“甘农3号”紫花苜蓿愈伤组织培养的最佳继代时间为15 d。

The hypocotyl of sterile seedlings of Medicago sativa L."Gannong No.3"is used as an explant to induce callus to determine the optimal subculture time for Medicago sativa L.callus.The browning and antioxidant enzyme activity of callus are evaluated under different subculture times.The results show that the browning degree of callus and activities of phenylalanine ammonia-lyase(PAL),catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD)increase with the increasing of subculture time.When the subculture time is 10 d,the browning rate of callus is the lowest,significantly reduced by 58.8%compared to the control(P<0.05).When the subculture time is 15 d,the browning rate is significantly reduced by 50.0%compared with the control(P<0.05).Besides,the activities of malondialdehyde(MDA)content,PAL,POD and CAT are significantly lower than those of the control(P<0.05),and the difference is not significant compared with the subculture time of 10 d(P>0.05).Therefore,the optimal subculture time for cultivating callus of Medicago sativa L."Gannong No.3"is 15 d.