不同倍性大青杨的光合特性及叶片解剖结构比较

通过对二年生二倍体、三倍体和四倍体大青杨叶片结构和光合特性的研究,探讨不同倍性大青杨生长性状差异的原因。结果表明：不同倍性大青杨的净光合速率（Pn）、光饱和点（LSP）、光补偿点（LCP）等光合指标差异显著。三倍体的最大净光合速率（Pmax）高出二倍体21%。叶片厚度、表皮细胞厚度、栅栏组织厚度、栅栏组织与海绵组织厚度的比值,都是三倍体和四倍体大青杨比二倍体高,且均呈现增加的趋势。其中,四倍体大青杨表皮细胞最厚,上下表皮分别高出二倍体64%和17%。三倍体大青杨的栅栏组织厚度及栅栏组织与海绵组织厚度的比值最大,比值高出二倍体50%。通过叶片光合特性和解剖结构比较证明,三倍体和四倍体大青杨对光的适应性和光合作用能力强于二倍体。

Comparison of Photosynthetic Characteristics and Leaf Anatomy Structure of Different Ploidy Populus ussuriensis Kom.

In order to investigate the reasons for differences among various ploidy Populus ussuriensis in growth traits,the comparative study on leaf structure and photosynthetic characteristics of two-year-old diploid,triploid and tetraploid P. ussuriensis was examined. The results showed that net photosynthetic rate （Pn）,light saturation point （LSP） and compensation point （LCP） among different ploidy P. ussuriensis were significantly different. The value of the maximum photosynthetic rate （Pmax） from the triploid plant was 21% higher than that from the diploid. Triploid and tetraploid P. ussuriensis were significantly increased in thickness of leaf,epidermis,palisade tissue and the ratio of palisade tissue to spongy tissue than the diploid. The sizes of upper and lower epidermal cells of the tetraploid plant were the largest,the values of which were 64% and 17% higher than those of the diploid. The triploid plant had a maximum in the thickness of palisade tissue and the ratio of palisade tissue to spongy tissue. The ratio of palisade tissue to spongy tissue of the triploid plant was 50% higher than that of the diploid plant. With leaf photosynthetic characteristics and anatomical study performed,the results indicated that triploid and tetraploid P. ussuriensis had a better accommodation to light and photosynthesis compared to the diploid.