外源激素IAA对不同玉米自交系耐深播特性的影响

Effects of Exogenous Hormone IAA on Deep Sowing Tolerance of Different Maize Inbred Lines

以玉米耐深播自交系N192和深播敏感自交系178为试材,在3 cm和15 cm播深条件下,施加2.0 mg/L的外源生长素(IAA)进行处理,研究外源IAA对不同耐深播玉米自交系中胚轴生长特性的影响。结果表明,施加外源IAA后,两个自交系的中胚轴、胚芽鞘及中胚轴和胚芽鞘之和均有所增加,中胚轴内过氧化物歧化酶活性(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性及木质素含量均呈上升趋势,且施加外源IAA的玉米自交系中胚轴组织细胞明显伸长,说明施加外源IAA可有效缓解深播对玉米幼苗的胁迫损伤。相关性分析和主成分分析得出,玉米自交系幼苗深播性鉴定评价指标中胚轴长、中胚轴和胚芽鞘之和、POD、SOD、CAT酶活性及木质素含量是主要评价指标,胚芽鞘长、胚芽鞘重、苗长可作为2级评价指标,根重可作为3级评价指标。

In order to study the effect of exogenous growth hormone(IAA)on mesocotyl growth characteristics of maize inbred lines(N192 and 178)with tolerance to deep sowing and sensitivity to deep sowing,exogenous growth hormone(IAA)of 2.0 mg/Lwas applied at 3 cm and 15 cm depth.The results showed that after the application of exogenous IAA,the mesocotyls,coleopheles and the sum of the mesocotyls and coleopheles of the two inbred lines increased,the activities of POD,SOD,CAT,and Lignin content in the mesocotyls increased,and the mesocotyls of the maize inbred lines with exogenous IAA extended significantly.The results indicated that exogenous IAA could effectively alleviate the stress damage of deep sowing to maize seedlings.Correlation analysis and principal component analysis were used to derive 3-level of evaluation indicators for the identification of deep-seededness in maize seedlings:the sum of mesocotyl length,mesocotyl and endosperm sheath;POD,SOD and CAT enzyme activity and the sum of Lignin content is the main evaluation index;Germinal sheath length,germinal sheath weight and seedling length can be used as secondary 2-level evaluation indicators,the secondary root weight can be used as a 3-level evaluation index.