Effect Of Light Quality And Gibberellin On Ornamental And Relative Physiological Characteristics Of Gerbera Jamesonii

This study took Gerbera jamesonii“Zixia”as the experimental material,the effects of three different light quality?white,red,and blue?and four different concentration of GA₃?0,50,125,200 mg/L?on its vegetative growth,flowering characteristics,physiological characteristics of leaves and the enzyme activity associated with flower color were studied,the results of different treatments on physiology and flowering were analyzed,so as to explore the optimum light quality and GA₃ concentration for flowering characteristics.The results are as follows:?1?The vegetative growth of G.jamesonii was promoted from different aspects by treating with GA₃,red light and blue light.The flowering characteristics under red light were better than others,not only was the flowering period advanced,but also the plant height,the flower diameter,the number of flowers and the flowering duration were prolonged under the treatments of red light and GA₃,compared with the control,the plant height,the flower diameter and the number of flowers were increased by 18.66%,10.13%and 86.67%respectively,the flowering period was 16d earlier,and the flowering duration was extended21 d under the treatment of red light+GA₃50 mg/L,while the treatments of blue light promoted to sprout new leaves and increased the leaf area,but it may inhabit the formation of flower bud,resulting in a decrease in the number of flowers.?2?After treating with GA₃,red light and blue light,the content of chlorophyll a and chlorophyll b in the leaves of G.jamesonii were significantly increased?P<0.05?,and the chlorophyll accumulation was effectively maintained in the latter flowering period,and the photosynthetic capacity was enhanced.During the whole flowering period,the contents of chlorophyll a and chlorophyll b were higher than others with the treatments of red light+GA₃50 mg/L and blue light+GA₃50 mg/L,among them,the content of chlorophyll was the highest under the treatment of red light+GA₃50 mg/L,which increased by 127.50%compared with the control in latter stage of blooming?the period of P6?.?3?Under the different light quality and dissimilar concentration of GA₃,the accumulation of soluble sugar was significantly promoted,the activity of superoxide dismutase?SOD?was enhanced effectively?P<0.05?.In addition,the treatments of red light+GA₃50 mg/L,red light+GA₃125 mg/L inhibited the accumulation of soluble protein and the increase of malondialdehyde?MDA?content in leaves,alleviated the degree of membranous damage,while the treatments of blue light+GA₃125 mg/L and blue light+GA₃200 mg/L promoted the accumulation of soluble protein.All three treatments delayed the senescence of leaves from different aspects,provided sufficient nutrients for normal growth of flowers and leaves.?4?The accumulation of anthocyanin was induced,the coloring of petals was improved,the activity of phenylalanine ammonialyase?PAL?was increased,the reduction of the activity of polyphenol oxidase?PPO?was accelerated,and the degradation of anthocyanins was alleviated under the treatments of GA₃ and blue light,the treatment of blue light+GA₃50 mg/L showed the best results,compared with the control,the content of anthocyanin was increased by 79.89%,the activity of phenylalanine ammonialyase increased by 23.50%,the activity of polyphenol oxidase was decreased by 59.39%in latter stage of blooming?the period of P6?.In conclusion,the treatments of GA₃,red light and blue light can improve the nutritional condition of“Zixia”entirely,and the combination of light quality and GA₃ treatments were more effective than single factor treatments.Red light was beneficial to early flowering,increase the number and quality of flowers,blue light contributed to petal coloring,but caused fewer flowers and smaller flower diameter.By conmprehensive analysis,the treatments of red light+GA₃50 mg/L and red light+GA₃125 mg/L had the best effects,which can effectively delay the aging of leaves,prolong the viewing time and increase the ornamental value.