Effect of abscisic acid on some salt stressed Maize Inbreds

ABSTRACT

The effect of exogenous ABA treatment on eight maize inbred lines [Zea maysL.] differing in their salt tolerance, with regard to some yield-related traits was examined. Also, fingerprints for the two salt-tolerant and the two salt-sensitive inbreds using RAPD-PCR markers were identified. From 20 maize inbred lines, four were chosen as salt-tolerant genotypes [L123a, G251b, L113a and Rg25] and four as salt-sensitive genotypes [Rg5, G227b, Rg1 and G13]. These eight maize inbreds were treated with 10-5 M abscisic acid [ABA] under5000 and 7000 ppm NaCl conditions. The effect of exogenous ABA on salt tolerance was tested by estimating some yield-related traits [plant height, total root length, shoot fresh weight, shoot dry weight and root dry weight]. The two most salt-tolerant [L123a and G251b] inbreds and the two most salt-sensitive [Rg1 and G13] were selected for detecting some biochemical and molecular genetic markers associated with salt tolerance. SDS-PAGE banding pattern showed differential responses with respect to salt tolerance and ABA treatment, while esterase and peroxidase isozyme profiles were weakly or negatively correlated with salt tolerance and ABA treatment. RAPD-PCR analysis showed that four random 10-mer primers, out of six, succeeded in differentiating salt-tolerant [L123a and G251b] from salt-sensitive [Rg1 andG13] inbreds, some specific markers for maize inbreds across RAPD-PCR analysis were determined. Twenty-seven of 57 RAPD markers were found to be inbred-specific, phylogenetic relationships between these inbreds were studied on the bases of RAPD-PCR patterns. Dendrogram analysis showed that, the inbreds were divided into two main groups and the most dissimilar one was the most salt-sensitive