Independence of Morphactin and Gibberellin Effects Upon Higher Plants

Inflorescence Initiation in Lolium Temulentum L. XIII. the Role of Gibberellins

“…When GA3 was applied as well as chlorflurenole, shoot apex length was restored beyond the level of the long-day controls, but the summit abnormality was still present in most plants. This suggests that the action of chlorflurenole is at least partly independent of GA3 action, as Mann et al (1966) and Tognoni, de Hertogh, and Wittwer (1967) have also concluded. These treatments are of interest, however, in that despite the apparent stasis of the summit of the apex due to chlorflurenole, the spikelets induced at pre-existing sites on the apex could reach the stage of floret differentiation when GA3 was added.…”

“…Chlorflurenole was found by Ziegler, Kohler, and Streitz (1966) not to affect gibberellin synthesis in Fusarium, but interacted with CCC and applied gibberellins in a way suggesting that it could be a competitive inhibitor of gibberellin action. However, subsequent work by Mann et al (1966) and Tognoni, de Hertogh, and Wittwer (1967) suggests that morphactins, like chlorflurenole, and gibberellins act independently. Abscisic acid, which can inhibit flowering in L. temulentum (Evans 1966;El-Antably, Wareing, and Hillman 1967), is known to interact with gibberellins in the control of bud dormancy (Eagles and Wareing 1964), ex-amylase production Varner 1966, 1967), and germination and growth of the radicle in lettuce (Aspinall, Paleg, and Addicott 1967).…”

Vegetative Propagation in Everbearing Strawberry as Influenced by a Morphactin, GA3, and BA 1

“…It may be that the rate of GA3 was insufficient to overcome the depressive effect of morphactin on the longitudinal growth. Mann et al (12) and Kohler (9) working with Citrus seedlings and Pisum sativum, found that GA3 does have a concentration-dependentcounteracting effect on the morphactin-induced inhibition of the shoot elongation growth.…”

Studies of Morphactin on the Growth and Auxin Distribution on Chrysanthemum morifolium Ramat1

“…Reports showed that this group of chemicals can be used as growth retardants (17), to induce parthenocarpy (14) and abscission (22,23), inhibit seed germination (6,16), destroy apical dominance (12), and affect photo and geotropic response (8,17). In some cases (8), it was shown that morphactin induced lateral branch development, even when treated specimens were not decapitated.…”

“…Both genetic and environmental factors may disrupt these processes and thereby reduce set. Genetic predisposition for a high proportion of embryo sacs with abnormal development or early degeneration was reported to be the cause of poor fruit set in 'Comice' pear (12), 'Constant' apricot (8) and 'Delicious' apple (10). A somatic mutant causing…”