空心莲子草在我国的适应性及入侵机制

空心莲子草是入侵我国的重要杂草之一,它在我国能广泛传播和迅速蔓延,与其自身特有的形态生理适应性、强大的繁殖特性和竞争力,以及传入地缺乏自然控制机制密切相关.空心莲子草从其原产地过渡到新的侵入地的过程中,在生态环境适应方面发生重大变化,产生一系列的形态结构、生理过程,以求适应陆地生活条件.其表型可塑性使得空心莲子草有更宽的生态幅,可利用的潜在资源范围也随之扩展;强大的营养繁殖能力,使其迅速产生大量的后代,在失去自然天敌调控的情况下,尤为适应其侵入种的生长、繁殖、发展和传播,种群数量的激增又会加速其传播扩散速度,导致空心莲子草爆发成灾.在综述空心莲子草在形态、生理、繁殖的适应性特征及天敌因素和入侵特性的基础上,根据前人的有关论述,分析了空心莲子草在我国的适应性特征及入侵机制,指出了空心莲子草在我国适应性及入侵机制应着重研究的方向,提出了综合治理和充分利用空心莲子草的对策.

Discussion on adaptability and invasion mechanisms of Alternanthera philoxeroides in China

Alternanthera philoxeroides is regarded as one of the worst weeds in China because of its invasiveness,potential for spreading,and economic and environmental impacts.It is a especially troublesome weed and invades both land and water,and it is very difficult to control.When growing on land it displaces other more favorable plants such as crops or native vegetation,and can be harmful to animals.When growing in fresh water,it can cover the entire water surface.Weed mats can also reduce oxygen exchange,affecting water plants and animals and reducing water quality.A successful invasion of Alternanthera philoxeroides not only depends on its bio-ecological of invasion,but also concerns the lack of nature control very nearly.The study on the invasive mechanism of Alternanthera philoxeroides will be beneficial for the prediction and management of this weed.Alternanthera philoxeroides grows and spreads quickly and does great harm to plant and animal in China due not only to its adaptability in morphologic and physiological,to its strong progenitive and rival capability,but also to the absence of natural controlled mechanisms.Alternanthera philoxeroides threatened the production and life of local people,did a lot of damage to the ecological systems,and affected the biodiversity.The mechanisms of Alternanthera philoxeroide spreading rapidly in China were their strong reproductive ability,adaptation and resistance,along with strong competitive ability and specific character,also with the resistance to barrenness and pollution and short of local competently competitive organisms or natural enemies.The anatomical structure of the organ of Alternanthera philoxeroides has both terrestrial characters and aquatic characters and the direction to which it is to develop will be determined by the water conditions in its habitats.The morphologic,physiological,progenitive adaptability of Alternanthera philoxeroides are reviewed in this paper.Main research direction in genetic foundation of adaptability and invasion mechanisms of Alternanthera philoxeroides in China is pointed out.And the study on the heredity structure of alligator weed should be combined with its adaptability and phenotype plasticity in China,which be propitious to identify the essence of successful invasion of Alternanthera philoxeroides.In terms of integrated control and utilization countermeasure,five aspects advanced in the paper are as follows:(1) it is principal to completely realize the distribution and harms of Alternanthera philoxeroides in China and collect correlative information;(2) it is essential to shut off the invasion approaches of alligator weed;(3) it is one of the effective measures to correctly choose biological and chemical herbicide and reduce secondary pollution;(4) natural enemies may be introduced or bred;(5) the study on the innoxious utilization of Alternanthera philoxeroides is probably effective control strategies.For example,study on decomposed water Alternanthera philoxeroides to be used as basal manure for crops should be carried out,and the technology of the weeds to be used as the material to produce the edible fungi and used as herbal medicine should be studied.The study on invasion of Alternanthera philoxeroides has already drawn scientists' attention now.So the paper is very important to summarize the past results,and the management approaches and strategies of Alternanthera philoxeroides suggested in this paper are also used for references.