狗牙根营养繁殖体对模拟水淹的生物学响应

Biological Response of Cynodon Dactylon Vegetative Propagates to Simulated Flooding

摘要:

研究了水淹条件下狗牙根(Cynodon dactylon)繁殖体的形态特征和生物量的变化及其水淹后的恢复状况。结果表明，水淹深度的增加会诱导植株茎快速增高，而叶片数则明显下降。水淹时间对植株叶片数、茎直径、茎与根长比的影响显著，而对分枝数、茎长、根长、茎节数不显著。植株地上部生物量和总生物量随着水淹时间的延长而显著减少，但地下部生物量的变化不显著。所有实验处理的植株水淹后都能存活且恢复生长。但水淹对恢复期植株的生长仍有影响，植株的茎长、根长、分枝数、直径、叶片数、叶长、宽度以及叶的长宽比都随水淹时间的延长而显著减少，但茎节数与叶片数的差异不显著。根、茎、叶生物量和植株总生物量也随着水淹时间的延长而减少。实验表明狗牙根繁殖体通过延长茎长、改变叶形和减少生物量等方式对水淹显示出较强的耐受能力。

Abstract:

The changes of Cynodon dactylon propagules under flooding were studied in morphology and biomass. Results showed that the stem length increased with increasing of flooding depth, whereas leaf number decreased obviously. Flooding duration had significant effects on leaf number, stem diameter, and ratio of stem length to root depth, but not on branch number, stem length, root depth, stem node number. The aboveground biomass and total biomass of plants decreased significantly with the prolongation of flooding time, but the underground biomass of plants changed little. Plants of all the treatments could survive and recovered after flooding. However, stem length, root depth, branch number, stem diameter, leaf number, leaf length, leaf width and ratio of leaf length to leaf width all decreased significantly with the increase of flooding duration during recovery, so did the stem, leaf, root biomass and total biomass. But node number and leaf number of plants showed no significant difference among treatments. It suggested that Cynodon dactylon had strong toleration to flooding by prolonging stem, changing leaf shape and reducing biomass.