皇竹草竞争抑制入侵植物假臭草的潜力

【目的】探索安全有效控制华南地区危害严重的入侵杂草假臭草Praxelis clematidea的方法,检验皇竹草Pennisetum hydridum是否具有竞争抑制乃至替代控制假臭草的潜力。【方法】设置一系列不同比例皇竹草与假臭草的混种盆栽试验,测定2种植物的竞争指数及形态特征。【结果】假臭草的竞争平衡指数为-0.97～-0.40,在所有比例的混种处理中均小于0,说明皇竹草始终处于竞争优势地位。皇竹草的单株生物量随着假臭草的种植比例增加而增加,从最低48.98 g增加至最高161.66 g;假臭草与皇竹草混种限制了假臭草的茎、叶的发育和生长,导致混种处理的假臭草单株总叶面积比单种假臭草减少43.4%～68.2%、单株总茎长减少49.4%～63.6%、单株分枝数减少46.1%～71.6%。【结论】皇竹草对假臭草有竞争抑制作用,具有替代控制假臭草的潜力。

Potential of Pennisetum hydridum for controlling invasive plant Praxelis clematidea

Objective To explore the method for safely controlling Praxelis clematidea, one of the most invasive plant in South China, and study the potential of Pennisetum hydridum to compete with and replace Praxelis clematidea.Method Pot experiment with a series of planting ratios of Pennisetum hydridum and Praxelis clematidea was conducted. Competitive indices and morphological traits of two plant species were measured.Result Competitive balance indices of Praxelis clematidea ranged from -0.97 to -0.40, lower than zero in all treatments with different planting ratios, indicating Pennisetum hydridum had a competitive dominance. The biomass per plant of Pennisetum hydridum increased from 48.98 g to 161.66 g with increasing ratio of planted Praxelis clematidea. Mixing two plant species suppressed growth and development of stem and leaf for Praxelis clematidea, and resulted in that total leaf area, total stem length and branch number per plant of Praxelis clematidea decreased by 43.4%-68.2%, 49.4%-63.6% and 46.1%-71.6% respectively compared with those in monoculture of Praxelis clematidea.Conclusion Pennisetum hydridum has competitive inhibition against Praxelis clematidea. It is a prospective candidate to control and replace Praxelis clematidea.