Effect of exogenous polyamines on flower bud retention in pistachio (Pistacia vera L.) trees.

摘要

Alternate bearing, the occurrence of high yield 'ON' year followed by low yield 'OFF' year, is striking in pistachio (Pistacia vera L.) trees. Flower buds of pistachio are formed a year before bloom, but abscise during the years with heavy crop ('ON' year). The present study was conducted to examine the effects of various concentrations of polyamines, such as putrescine, spermidine and spermine, on flower bud retention of pistachio trees cv. Ahmad Aghaei. The results showed that exogenous application of polyamines significantly increased the flower bud retention, leaf chlorophyll content, leaf and floral bud nitrogen and leaf area. Among the three polyamines tested, the highest concentration (0.1 mM) of spermine was the most effective in increasing flower bud retention. There was a positive relationship between leaf and flower bud nitrogen content and flower bud retention.