Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil wate...Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil water supply, ramet pairs of the species were subjected to heterogeneous water supply by which either mother ramets or daughter ramets were in high or low soil water supply, respectively, in the Maowusu (Mu Us) Sandy Land of Nei Mongol. The results showed that the phenotypic characteristics of the individual ramets of C epigejos were greatly influenced by the heterogeneous water supply. The ramets treated with high water supply significantly produced more new rhizomes and more offspring (ramets), and accumulated more shoot biomass, and allocated more biomass to their shoots than those treated with low water supply. In comparison with the daughter ramets in homogeneous soil water supply, phenotypic characteristics, in terms of new rhizome growth, the production of new offspring, and the biomass allocation pattern, of the daughter ramets within the pairs of the species were not significantly changed, no matter that high or low soil water supply to mother ramets. The phenotypic responses of mother ramets to soil water supply were similar to those of daughter ramets. From these results, it is inferred that the interconnected ramets of C epigejos response phenotypically to their local soil water rather than to the soil water experienced by the interconnected ramets. The interconnected ramets of C epigejos might be independent of each other in water relationship, although they are physically interconnected with rhizome segments. The physiological independence of interconnected ramets might facilitate the risk spreading and thus enhance the genet survivorship under the frequent drought stresses in Mu Us Sandland.展开更多
Variations in Caladium humboldtii cv. ＇Phraya Savet＇ from in vitro culture were observed. Callus and small shoots were induced from unexpanded leaf segments cultured on modified MS medium supplemented with 2.69 p.M ...Variations in Caladium humboldtii cv. ＇Phraya Savet＇ from in vitro culture were observed. Callus and small shoots were induced from unexpanded leaf segments cultured on modified MS medium supplemented with 2.69 p.M l-Naphthalene acetic acid （NAA） and 17.76 μM N6-Benzyladenine （BA）. Shoots were transferred onto modified MS medium supplemented with 8.88 μM BA for shoot multiplication. Subsequently, roots were induced on MS without growth regulator. The regenerated plantlets were vigorously grown in glasshouse conditions. From 4 morphological groups （leaf color ratio, leaf color, petiole and leaf pattern）, the regenerated ＇Phraya Savet＇ caladium plants were divided into 6 types. The occurrence of variants was 52%. Most of the mutated plants were observed from only leaf color ratio （green ： white） and leaf shape. The most significance for commercial value from mutated clones was round leaf obtaining 20%. Characteristics of new clones from somatic hybridization between C humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ using thin cell layer technique from in vitro calli were investigated. Each thin cell layer of induced callus, about 0.5 - 1 mm thick, from both caladiums was alternately laid on the top of each other for 8 layers. Subsequently, the combination of thin cell layers was cultured and the regenerated plantlets were grown in glasshouse conditions. From 3 morphological groups （leaf pattern, leaf color and petiole）, the regenerated caladium plants were found dissimilarly to both original caladiums at 85 percent with 8 types of different characters. Somatic hybridization between C. humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ gave rise to a number of most hybrids with all conserving C. bicolor characters.展开更多
文摘Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil water supply, ramet pairs of the species were subjected to heterogeneous water supply by which either mother ramets or daughter ramets were in high or low soil water supply, respectively, in the Maowusu (Mu Us) Sandy Land of Nei Mongol. The results showed that the phenotypic characteristics of the individual ramets of C epigejos were greatly influenced by the heterogeneous water supply. The ramets treated with high water supply significantly produced more new rhizomes and more offspring (ramets), and accumulated more shoot biomass, and allocated more biomass to their shoots than those treated with low water supply. In comparison with the daughter ramets in homogeneous soil water supply, phenotypic characteristics, in terms of new rhizome growth, the production of new offspring, and the biomass allocation pattern, of the daughter ramets within the pairs of the species were not significantly changed, no matter that high or low soil water supply to mother ramets. The phenotypic responses of mother ramets to soil water supply were similar to those of daughter ramets. From these results, it is inferred that the interconnected ramets of C epigejos response phenotypically to their local soil water rather than to the soil water experienced by the interconnected ramets. The interconnected ramets of C epigejos might be independent of each other in water relationship, although they are physically interconnected with rhizome segments. The physiological independence of interconnected ramets might facilitate the risk spreading and thus enhance the genet survivorship under the frequent drought stresses in Mu Us Sandland.
文摘Variations in Caladium humboldtii cv. ＇Phraya Savet＇ from in vitro culture were observed. Callus and small shoots were induced from unexpanded leaf segments cultured on modified MS medium supplemented with 2.69 p.M l-Naphthalene acetic acid （NAA） and 17.76 μM N6-Benzyladenine （BA）. Shoots were transferred onto modified MS medium supplemented with 8.88 μM BA for shoot multiplication. Subsequently, roots were induced on MS without growth regulator. The regenerated plantlets were vigorously grown in glasshouse conditions. From 4 morphological groups （leaf color ratio, leaf color, petiole and leaf pattern）, the regenerated ＇Phraya Savet＇ caladium plants were divided into 6 types. The occurrence of variants was 52%. Most of the mutated plants were observed from only leaf color ratio （green ： white） and leaf shape. The most significance for commercial value from mutated clones was round leaf obtaining 20%. Characteristics of new clones from somatic hybridization between C humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ using thin cell layer technique from in vitro calli were investigated. Each thin cell layer of induced callus, about 0.5 - 1 mm thick, from both caladiums was alternately laid on the top of each other for 8 layers. Subsequently, the combination of thin cell layers was cultured and the regenerated plantlets were grown in glasshouse conditions. From 3 morphological groups （leaf pattern, leaf color and petiole）, the regenerated caladium plants were found dissimilarly to both original caladiums at 85 percent with 8 types of different characters. Somatic hybridization between C. humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ gave rise to a number of most hybrids with all conserving C. bicolor characters.
