An estimation of the effects of synthetic auxin and cytokinin and the time of their application on some morphological and physiological characteristics of Medicago x varia T. Martyn

Abstract

The aim of the experiment was to determine the effects of synthetic auxin and cytokinin and the time of their application on some morphological and physiological characteristics of Medicago x varia T. Martyn grown under controlled conditions. The experiment was to check whether an application of exogenous hormones during vegetative and generative stages of the plant had an effect on above-ground mass development, on nitrate reductase activity and on plastid pigments content. Experiment factor was synthetic auxin and cytokinin and the date of their application. Auxin was applied in the form of a synthetic indole-3-butyric acid, while cytokinin was sprayed as synthetic 6-benzylaminopurine. The control plants were treated with distilled water. Depending on the experimental variant, spraying was applied at the sixth true leaf stage and at the first flower bud stage. The research showed that the response of the alfalfa plants to the application of cytokinin and auxin was not uniform. It seems that the most effective was the application of a mixture of them both but only during the vegetative stage.Additionally, cytokinin caused an increase in plastid pigments content in alfalfa leaves. On the other hand, a mixture of auxin and cytokinin triggered the highest nitrate reductase activity in alfalfa roots and raised the ratio of total chlorophyll content to carotenoids. Synthetic auxin caused the decrease of the levels of most parameters compared to the control.

Metabolic and physiological changes induced by plant growth regulators and plant growth promoting rhizobacteria and their impact on drought tolerance in Cicer arietinum L.

“…The effect of PGRs and PGPRs treatment was more pronounced in the sensitive genotype compared to the tolerant genotype. Previous studies demonstrated that the drought-induced reduction in chlorophyll content and chlorophyll fluorescence led to a decrease in photosynthesis and overall plant growth [55, 56]. The combined treatment significantly enhanced the chlorophyll fluorescence and chlorophyll content values in the PGRs/PGPRs treated plants in both genotypes.…”

Comparative Study between Exogenously Applied Plant Growth Hormones versus Metabolites of Microbial Endophytes as Plant Growth-Promoting for Phaseolus vulgaris L.

“…All of the isolated endophytic fungi were found to promote the growth of O. sativa L. “Cempo Ireng” [ 70 ]. Concerning the effect of exogenously applied hormones on plant growth, spraying exogenous auxins and cytokinin such as IAA and 6-benzylaminopurine resulted in an asymmetrical response of the treated alfalfa plants during their vegetative growth, while their application as a mixture was most effective and increased the biomass of plant shoots; however, the clearest effect was for the rate of total chlorophyll to carotenoid content [ 71 ]. Some endophytic fungi isolated from maize and rice plants, such as Fusarium , Sarocladium , Aspergillus and Penicillium , have been confirmed to be determining factors in plant growth improvement [ 72 ].…”

Growth and accumulation of dry mass in squashes with fruiting induced by cytokinin and auxin

“…This same method (via leaves) stood out, when compared to the application via ovary, for all proportions, except for 0/100%. Sosnowski et al (2016) stated that the cytokinin applied during the vegetative stage induces the increase in the number of leaves, but diminishes their expansion. However, as seen in this paper, cytokinin in equal proportion with auxin, applied on the leaves, may promote a better relationship between the expansion and the number of leaves, with a direct action on the organ, when compared with the application via ovary.…”