Effect of fruit load on 9,10-ketol-octadecadienoic acid (KODA), GA and jasmonic acid concentrations in apple buds

Effects of fruit load, shading, and 9,10-ketol-octadecadienoic acid (KODA) application on MdTFL1 and MdFT1 genes in apple buds

“…The presence of endogenous gibberellic acid (GA) from the seeds as well as the application of GA are known to inhibit flowering in apples (Ramírez et al 2004). In contrast to GA, endogenous KODA concentrations were high in the apical buds of trees whose rate of flower bud formation was also high (Kittikorn et al 2010). Therefore, KODA may be associated with flower bud formation in apples.…”

“…Chemicals KODA (9,10-ketol-octadecadienoic acid) was prepared as described previously (Kittikorn et al 2010 …”

“…Each apical bud was longitudinally dissected, and the rate of flower bud formation was determined with a stereomicroscope. In accordance with a previously reported method (Kittikorn et al 2010), buds in which the apical meristem was dome-shaped were counted as flower buds. The rate of flower bud formation was decided by the number of flower buds in 90 apical buds.…”

“…Endogenous gibberellins were extracted and quantified according to the procedure described by Kittikorn et al (2010). As an internal standard, 200 ng each of [ 2 H 2 ] GA 1 and [ 2 H 2 ] GA 4 was added to the 80% MeOH extracts.…”

“…Contrary to the functional role of TFL1, FT1 promoted flowering by altering the expression of other endogenous genes (Kardailsky et al 1999;Esumi et al 2007). Environmental factors such as fruit load and shading influence flower bud formation in apples (Rom 1996;Kittikorn et al 2010). However, there is no report on the relationship between environmental factors and the expression of genes that are associated with flower bud formation.…”