关键词: 遮荫, 美丽胡枝子, BADH 基因, 叶形态, 光合特性

Abstract: The aim of this study was to investigate the effects of shading on the transgenic Lespedeza formosa with expressing BADH. Two transgenic L. formosa lines and wild-type plants were selected as materials and were shaded. The betaine aldehyde dehydrogenase activity, glycinbetaine, chlorophyll, leaf shape, net photosynthetic rate, transpiration rate, light compensation point, light saturation point et al. were assayed in transgenic and wild-type plants under different irradiation regimes (light transmittance 100%, 75%, 34% and 11%).The result was as follows: 1) The T1 generation of transgenic L. formosa plants showed trait differentiation in leaf color. The proportion of green leaves and yellow leaves was 3 ∶1 and accorded with Mendelian Law separation. 2) Low light induced the expression of BADH gene and increased betaine aldehyde dehydrogenase activity. Higher glycinbetaine content was accumulated under low light. 3)The chlorophyll a and b concentrations, leaf length, leaf width, specific leaf dry mass, fresh mass per unit area of leaf, daily net photosynthetic rate, daily transpiration rate and apparent quantum yield in transgenic plants were significantly higher than those in wild-type plants under low light of light transmittance 34% or 11%. But chlorophyll a/b ratio, specific leaf area, light compensation point and light saturation point in transgenic plants were significantly lower than those in wild-type plants. 4)There was no significant difference between transgenic and wild-type plants in most of assayed indexes when plants grew in full nature light or light transmittance 75%. 5)The transgenic L. formosa with expressing BADH could more adapt to weak light than wild-type plants.

Key words: shading, Lespedeza formosa, BADH, leaf shape, photosynthetic characteristics