Morphological and photosynthetic characteristics of Ligularia stenocephala with shading

Key words: 
• botany /
• Ligularia stenocephala /
• shading /
• morphological characteristics /
• photosynthetic characteristics

Abstract: Ligularia stenocephala（Compositae），a perennial herb，is a potential ground-cover plant. Shading（0，55%，and 75%） was applied to L. stenocephala to determine a theoretical basis for morphological and photosynthetic characteristics in plantation and landscape application. Results indicated that relative growth rate was higher with 55% shading. The diurnal variation of net photosynthesis（Pn） in L. stenocephala with all shade conditions presented a double-peak curve with a midday depression for Pn at 13:00. For shading of 0，55%，and 75%，the light compensation points（LCP） were 13.20，15.10，and 8.63 μmol·m －2·s－1；the light saturation points （LSP） were 919.66，749.20，and 727.34 μmol·m －2·s －1；the maximum net photosynthetic rates were 13.20，15.10，and 8.63 μmol·m－2·s－1；and apparent quantum efficiencies were 0.040 1，0.046 0，and 0.046 3，respectively. The maximum Pn rate significantly（P＜0.05） increased，and LSP were significantly（P＜0.05） decreased with 55% and 75% shading，with shading of 75%，LCP were significantly lower than shading of 0 and 55%. This result indicated that L. stenocephala was adapted to weak light. Thus，L. stenocephala is a shade tolerant plant that can be planted under low light conditions. ［Ch，2 fig. 4 tab. 16 ref.］