The goal of this work was to analyze the phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf. subsp. rupestris to environmental factors ...The goal of this work was to analyze the phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf. subsp. rupestris to environmental factors also in consideration of global change. We used seedlings of the two subspecies originated from wild plants from the natural habitats in Sicily and cultivated in the Botanical Garden of Rome. Leaf morphological and physiological traits and growth dynamic were analyzed as well as the response to an imposed water stress experiment. The results underlined a higher relative growth rate in plant height (RGRH, cm·cm-1·d-1) in B. rupestris subsp. rupestris also attested by the highest plant height (H, cm), leaf area (LA, cm2), specific leaf area (SLA, cm·g-1), total leaf area per plant (TLA, cm2) and total plant dry mass (PDM, g plant-1). Moreover, the significantly highest net photosynthetic rates (A, μmol CO2 m-2·s-1) during the study period of this subspecies was related to the high Chlorophyll content (Chl, SPAD units). B. rupestris subsp. rupestris was also the most tolerant subspecies to imposed water stress showing the highest relative water content (RWC, %), A and water use efficiency (WUE, μmol·mmol-1).展开更多
Lucetta,a cultivar of Eustoma grandiflorum( Raf.) Shinners,was subjected to treatments of different light intensities( 100%,85%,70% and 55% of natural light intensity) and different light durations( 10-h natural light...Lucetta,a cultivar of Eustoma grandiflorum( Raf.) Shinners,was subjected to treatments of different light intensities( 100%,85%,70% and 55% of natural light intensity) and different light durations( 10-h natural lighting,12-h natural lighting,12-h natural lighting+ 2-h LED lighting,12-h natural lighting + 4-h LED lighting),and then its plant height,crown width,stem thickness,stalk thickness,total flower number,flowering period and growth situation were analyzed. The results show that E. grandiflorum( Raf.) Shinners is sensitive to the changes in light intensity. Under 85% of natural light intensity( 40 000-50 000 lux),E. grandiflorum( Raf.) Shinners grew faster,bloomed earlier with more flowers,and was taller,thicker,more robust,higher in yield,larger in pedicel length,and better in cut flower quality,without rosette phenomenon. Long-term exposure to low-intensity light would led to slow growth,thin stalk,delayed flowering,low yield and reduced cut flower quality in E. grandiflorum( Raf.) Shinners. The illumination duration of more than 12 h could promote the differentiation of flower buds,increase the plant height,increase the length of pedicels of E. grandiflorum( Raf.) Shinners. Extending the light duration by 2-4 h at night,that is,14-16 h of illumination was the most ideal illumination time for the growth of E. grandiflorum( Raf.)Shinners. A longer photoperiod could promote the growth and bring forward the blooming of E. grandiflorum( Raf.) Shinners. The longer the illumination time,the higher the plant. The optimum illumination time was between 14 and 16 h. When the illumination duration was shorter than 12 h,the growth of E. grandiflorum( Raf.) Shinners was retarded,and its flowering was also delayed.展开更多
文摘The goal of this work was to analyze the phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf. subsp. rupestris to environmental factors also in consideration of global change. We used seedlings of the two subspecies originated from wild plants from the natural habitats in Sicily and cultivated in the Botanical Garden of Rome. Leaf morphological and physiological traits and growth dynamic were analyzed as well as the response to an imposed water stress experiment. The results underlined a higher relative growth rate in plant height (RGRH, cm·cm-1·d-1) in B. rupestris subsp. rupestris also attested by the highest plant height (H, cm), leaf area (LA, cm2), specific leaf area (SLA, cm·g-1), total leaf area per plant (TLA, cm2) and total plant dry mass (PDM, g plant-1). Moreover, the significantly highest net photosynthetic rates (A, μmol CO2 m-2·s-1) during the study period of this subspecies was related to the high Chlorophyll content (Chl, SPAD units). B. rupestris subsp. rupestris was also the most tolerant subspecies to imposed water stress showing the highest relative water content (RWC, %), A and water use efficiency (WUE, μmol·mmol-1).
文摘Lucetta,a cultivar of Eustoma grandiflorum( Raf.) Shinners,was subjected to treatments of different light intensities( 100%,85%,70% and 55% of natural light intensity) and different light durations( 10-h natural lighting,12-h natural lighting,12-h natural lighting+ 2-h LED lighting,12-h natural lighting + 4-h LED lighting),and then its plant height,crown width,stem thickness,stalk thickness,total flower number,flowering period and growth situation were analyzed. The results show that E. grandiflorum( Raf.) Shinners is sensitive to the changes in light intensity. Under 85% of natural light intensity( 40 000-50 000 lux),E. grandiflorum( Raf.) Shinners grew faster,bloomed earlier with more flowers,and was taller,thicker,more robust,higher in yield,larger in pedicel length,and better in cut flower quality,without rosette phenomenon. Long-term exposure to low-intensity light would led to slow growth,thin stalk,delayed flowering,low yield and reduced cut flower quality in E. grandiflorum( Raf.) Shinners. The illumination duration of more than 12 h could promote the differentiation of flower buds,increase the plant height,increase the length of pedicels of E. grandiflorum( Raf.) Shinners. Extending the light duration by 2-4 h at night,that is,14-16 h of illumination was the most ideal illumination time for the growth of E. grandiflorum( Raf.)Shinners. A longer photoperiod could promote the growth and bring forward the blooming of E. grandiflorum( Raf.) Shinners. The longer the illumination time,the higher the plant. The optimum illumination time was between 14 and 16 h. When the illumination duration was shorter than 12 h,the growth of E. grandiflorum( Raf.) Shinners was retarded,and its flowering was also delayed.
