Gamma rays induced mutagenesis in Limonium sinuatum

English. Limonium is belonging to the Plumbaginaceae family cultivated for dried or cut flowers. A combination of in vitro techniques and radiation induced mutagenesis has been used to improve morphological variations and colour type, in different ornamental plants. The aim of this study was to evaluate the induction of mutations in morphological characteristics of Limonium sinuatum. To study their radiosensitivity, shoots were exposed to different doses of gamma rays (10, 20, 30, 40 and 60 Gy) from a cobalt source. Dose rate were 0.89 Gy/min (Dose I) and 8,17 Gy/min (Dose II). Treated shoots were propagated in vitro and, after acclimatization to in vivo conditions, they were transplanted in pot filled with peat based medium and transferred into a greenhouse. After 75% of plants were flowering, observations such as plant height, number of leaves, flower colour, number and height of floral stems were recorded. Based on results, the radiosensitivity studied was 20 Gy. (Dose I). The 10 Gy (Dose I) affects the leaves number and the floral stem height. There were no significant differences between the treatments about the plant size, the number of floral stems and the flower colour. The 20 Gy (Dose I) treatment did not show differences respect to the control plants. The above findings showed that this technique has the potential for increasing the genetic variation in Limonium sinuatum

Italian. La commercializzazione del Limonium richiede una diversificazione del prodotto in termini di colorazione del fiore e di architettura della pianta. Pertanto, obiettivo di questo lavoro e' stato quello di ottenere, attraverso raggi gamma, mutanti interessanti per il mercato floricolo. Per la prova di mutagenesi fisica sono stati utilizzati germogli in vitro di L. sinuatum (cv Heavenly blue) irraggiati a dosi crescenti. La soglia di radiosensibilita' e' stata determinata in 20 Gy. Dopo il trattamento i germogli sono stati ambientati in vivo e coltivati in serra. Alla fioritura sulle piante sono stati eseguiti i rilievi fenologici. Le piante trattate con 10 Gy hanno mostrato differenze significative rispetto al controllo per numero di foglie e per altezza degli steli fiorali. Nessuna differenza significativa e' stata osservata tra il controllo e le piante trattate con la dose di 20 Gy