不同替代程度对葎草控制喜旱莲子草光合作用的影响

Effects of Replacement Control with Humulus scandens on Photosynthesis of the Invasive Plant Alternanthera philoxeroides

为了更好地阐释替代控制机制,开展了不同替代程度对葎草控制喜旱莲子草光合作用的影响。将葎草与喜旱莲子草按照4种比例进行种植(3∶3、2∶4、4∶2和0∶6),于2017年8月中旬对喜旱莲子草的光合作用参数进行测定,结果表明,4:2处理喜旱莲子草的净光合速率为单峰现象,净光合速率1 d内均较低,其余处理均为双峰现象,且0:6处理午休现象明显。于2017年6、8和10月晴朗天气对4种处理喜旱莲子草的净光合速率进行测定,3个月中,4∶2处理喜旱莲子草的净光合速率均为单峰现象,且最大峰值出现在10:00,随后逐渐降低。6月,4∶2处理喜旱莲子草的日均净光合速率和最大净光合速率均最大,8和10月4∶2处理的喜旱莲子草日均净光合速率和最大净光合速率较6月迅速降低,显著低于其他处理。对4种处理3个月的喜旱莲子草叶绿素进行测定,除6月2∶4处理喜旱莲子草的叶绿素含量显著低于其他处理外,8和10月各处理间叶绿素含量差异均不显著。

In order to better explain the mechanism of the replacement control to invasive plant,the effects of the native plant Humulus scandens (Lour.) Merr.on the photosynthesis of the invasive plant Alternanthera philoxeroides (Mart.) Griseb.were studied with the different replacement degrees.Four treatments were setted,3∶3,2∶4,4∶2,6∶0 and 0∶6 were planted in 4 proportions.The results showed that the net photosynthetic rate of 4 ∶2 treatment was single peak,and the net photosynthetic rate was lower in one day,and the other treatments were double peaks in the middle of August 2017.In June 2017,August and October,the net photosynthetic rate of 4 ∶2 treatment was one peak,and the maximum peak appeared at 10 ∶00,then gradually decreased.The maximal net photosynthetic rate and daily net photosynthetic rate of the 4 ∶2 treatment were both higer than other treatment June,which was significantly lower than that in August and October.The chlorophyll content of the lotus grass was measured.In the June 2 ∶4 treatment,the chlorophyll content of Alternanthera philoxeroides was significantly lower than the other treatments.In August and October,the differences of chlorophyll content were not significant.