不同光照对广玉兰1年生移栽苗的生长影响

Effect of different light intensities on growth of 1-year Magnolia grandiflora transplants

通过设置4个不同的[光]照度(100%、75%、47%、25%)研究了广玉兰Magnolia grandiflora1年生移栽苗的生长情况。结果表明,在第四纪红色黏土上,广玉兰在不同的[光]照度下成活率较高,均达91%以上,以47%时最高,达95.83%;苗高总生长量表现为47%>75%>25%>100%,47%时净增长量最大;地径总生长量表现为47%>100%>75%>25%,同样,47%时净增长量最大;叶的生长大小相对一致;叶绿素含量、净光合速率、蒸腾速率的变化也相对稳定,无太大反差。综合评定结果表明,在第四纪红色黏土上,广玉兰移栽苗对不同[光]照度具有不同的可塑性和适应性,光强为47%时生长最好,适当的遮荫更能促进苗木的生长。

The growth of 1-year Magnolia grandiflora transplants was studied under four different light intensities （ 100% ,75% ,47% and 25% ）. The results showed that the survival rate of Magnolia grandiflora on quaternary red clay was higher under different light intensities, averaged above 91%. When 47 % light intensity was applied, the survival rate reached 95.83%. The increase of total height volume was in an order of 47% 〉 75% 〉 25% 〉 100% and under 47% light intensity,the net inerease was the highest. The invrease of total underground diameter volume was in an order of 47% 〉 100% 〉75% 〉25% and under 47% light intensity,the net increase was also the highest. The growth of leaves was relatively consistent and the chlorophyll content, net photosynthetic rate, transpiration rate were relatively stable. By comprehensive assessment the results showed that on quaternary red clay, Magnolia grandiflora manifested the different plasticity and adaptability under different light intensities. The 47% light intensity was the best and the proper shading would promote the growth of seedlings.