M.A. Thesis:

Effect of foliar application of ۶-benzylaminopurine on growth characteristics of chickpea under salinity stress

In order to investigate the effect of foliar application of 6-benzylaminopurine (BAP) on root and shoot morphological characteristics of chickpea under salinity stress, a factorial experiment in a randomized complete block design with three replications was carried out in greenhouse of agricultural faculty, Islamic Azad University, Sabzevar branch. Experimental factors included four levels of salinity stress: 0 (control), 4, 8 and 12 dS/m and BAP concentration at three levels: 0, 5 and 50 mg/l. Foliar application of BAP was performed in two stages of complete plant establishment and one month after that. Results showed that salinity stress had no significant effect on average root diameter, but decreased plant height, root volume, total root area; total root length and root dry weight. The dry weight of the shoot was increased at 4 dS/m salinity and significantly decreased at 8 and 12 dS/m salinity levels. The foliar application of BAP had no positive effect on plant height and shoot dry weight in the absence of salt stress, but increased plant height and dry weight of shoot in salinity stresses of 4, 8 and 12 dS/m. The highest plant height was obtained with 5 mg/l BAP foliar application at 4 dS/m salinity and with 50 mg/l BAP foliar application at 8 and 12 dS/m salinity levels. In contrast, foliar application of 50 mg/l BAP produced the highest dry weight of shoot at 4 and 8 dS/m salinity levels. The highest dry weight of the shoot at 12 dS/m salinity level was obtained with foliar application of 5 mg /l BAP. The foliar application of 5 mg/l BAP significantly increased root volume; total root area and total root length in the absence of salt stress, but had no significant effect on average root diameter and root dry weight. Foliar application of BAP did not have a positive effect on reducing the effects of salinity stress on root growth, and even at different levels of salinity, reduced the volume, total area, total length and dry weight of root compared to non-foliar application conditions. According to the results, two foliar applications of 50 mg/l BAP are recommended to reduce the negative effects of salinity stress on the shoot growth of chickpea.

Keywords: Salt stress, cytokinin, morphology, foliar application, chickpea