Effect Of Water Stress And Exogenous ALA On Gladious Growth

Gladiolus is one of the four famous traditional cut flowers favorited by the people. Flowering time and the quality improvement are very important for cut gladiolus production. The effects of water stress on growth and development of gladiolus and relationship between water regulation and flowering control in field production are studied in present paper.The effects of exogenous ALA on gladiolus growth are observed, in order to provide theoretical basis for cut gladiolus production. The research results were as follows:1. The effects of soil moistures on gladiolus’s growth were different. Water stress from20%to30%of normal soil moisture inhibited seriously the growth of gladiolus. Water stress from20%to30%and45%to55%of the soil moisture reduced the chlorophyll content of gladiolus leaf, increased malondialdehyde (MDA) content, enhanced SOD and POD activity, increased obviously osmoregulation substances proline and soluble protein content.2. The effects of different soil moistures and different duration time on gladiolus’s flower time were different under normale management. The results showed that effect2of flowering regulation were more obvious when gladiolus plants were treated by water stress started45days before flowering, then continue watering and keeping soil moisture content at60%-80%.3. The external morphology, inflorescence and flower diameter, corm size, ratio of corm height and diameter, growth period of gladiolus were controlled by concentrations of ALA and types of treatment, root treatment or foliar spray. Among20mg/L,40mg/L,80mg/L and160mg/L ALA root treatment, the effect of80mg/L ALA was significant. Among20mg/L,120mg/L,220mg/L,320mg/L ALA foliar spray, the effect of220mg/L ALA was more obvious. Comparison of root and leaf treatment, the effect of former was better than the latter on plant growth and development of Gladiolus.4. Exogenous ALA had a great influence on chlorophyll content of gladiolus. The chlorophyll content, chlorophyll a, carotenoids and chlorophyll a/b ratio of gladiolus increased by means of root irrigation and foliar spray treatments, while chlorophyll b content had little change.80mg/L ALA root treatment could promote the chlorophyll concentration, and220mg/L ALA foliar treatment could promote the formation of carotenoids. 5. The test results of Pn, Tr, Gs, Ci showed that the gladiolus leaf had an different photosynthesis ability by different concentrations of ALA treatment.80mg/L root treatment,220mg/L foliar treatment were more effective on increase of net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs).80mg/L root treatment,320mg/L foliar treatment were more effective on decrease of the intercellular carbon dioxide (Ci) concentration.6. Enzyme activity of SOD and POD increased after Gladiolus leaves were treated by ALA, thereby inhibiting the production of MDA and then its content decreased, when80mg/L ALA root treatment was more effective on promotion of SOD enzyme activity and on decrease the oxidation damage of MDA on Gladiolus leaves.160mg/L ALA root treatment was more effective on promotion of POD enzyme activity. The osmotic adJustment substances were promoted by ALA treatment.160mg/L ALA root treatment was more effective on promotion of free proline and soluble protein content.