Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During rang...Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan.展开更多
Merremia boisiana(Gagnep)van Ooststr.is a noxious fast growing woody vine and is able to grow overtop other plants,causing the death of plants underneath and forming monospecies stands.To formulate management response...Merremia boisiana(Gagnep)van Ooststr.is a noxious fast growing woody vine and is able to grow overtop other plants,causing the death of plants underneath and forming monospecies stands.To formulate management responses,we assessed its seed and vegetative reproduction efficacy through indoor and field experiments.The number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172,with an average of 80.80.Counting the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each infructescence.Seed vitality tests using red ink indicated that only 68.6%of hard testa and filled seeds were viable.The emergence rate of scarified hard testa seeds in the sand bed was 31.96%.Under imitated natural conditions,8%of hard testa seeds could germinate,and 9%still retained their germination potential in one year.Thus,seedlings should be monitored and removed in a timely fashion after any attempt of clearing.Moving soil or transplanting plant from infested patches should be strictly prohibited at least for several years.All considered,an infructescence contributed 0.3 seedlings.The investigation in the field found no seedlings either inside or at the perimeter of the patch,suggesting scant expansion by means of seed dispersal.Therefore,the elimination effort could be focused on a relatively restricted scale of patches.Of 630 cuttings of young shoots,old shoots and old lying shoots with or without growth regulators,there were only four(or 0.63%)established individuals.Air-layering shoots all died in two months.Poor cuttings and airlayering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely,and thus mechanical removal was safe.展开更多
旋花科植物金钟藤在中国华南地区已蔓延暴发成为"森林杀手",已引起各界的高度关注。该文对金钟藤的系统归隶、基名与异名、模式标本、分类文献,以及相关种进行考证和分析,澄清了一些误解和标本鉴定的错误,论证了金钟藤变种黄...旋花科植物金钟藤在中国华南地区已蔓延暴发成为"森林杀手",已引起各界的高度关注。该文对金钟藤的系统归隶、基名与异名、模式标本、分类文献,以及相关种进行考证和分析,澄清了一些误解和标本鉴定的错误,论证了金钟藤变种黄毛金钟藤在中国仅产于广西,而云南产的黄毛金钟藤实为铜钟藤,并把Merremia biosiana var.sumatrana van Ooststr.作黄毛金钟藤的新异名处理。展开更多
文摘Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan.
基金supported by the National Natural Science Foundation of China(Grant No.30370243)The National Nonprofit Institute Research Grant of CATAS-EPPI(No.2007hzs1J005).
文摘Merremia boisiana(Gagnep)van Ooststr.is a noxious fast growing woody vine and is able to grow overtop other plants,causing the death of plants underneath and forming monospecies stands.To formulate management responses,we assessed its seed and vegetative reproduction efficacy through indoor and field experiments.The number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172,with an average of 80.80.Counting the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each infructescence.Seed vitality tests using red ink indicated that only 68.6%of hard testa and filled seeds were viable.The emergence rate of scarified hard testa seeds in the sand bed was 31.96%.Under imitated natural conditions,8%of hard testa seeds could germinate,and 9%still retained their germination potential in one year.Thus,seedlings should be monitored and removed in a timely fashion after any attempt of clearing.Moving soil or transplanting plant from infested patches should be strictly prohibited at least for several years.All considered,an infructescence contributed 0.3 seedlings.The investigation in the field found no seedlings either inside or at the perimeter of the patch,suggesting scant expansion by means of seed dispersal.Therefore,the elimination effort could be focused on a relatively restricted scale of patches.Of 630 cuttings of young shoots,old shoots and old lying shoots with or without growth regulators,there were only four(or 0.63%)established individuals.Air-layering shoots all died in two months.Poor cuttings and airlayering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely,and thus mechanical removal was safe.
文摘旋花科植物金钟藤在中国华南地区已蔓延暴发成为"森林杀手",已引起各界的高度关注。该文对金钟藤的系统归隶、基名与异名、模式标本、分类文献,以及相关种进行考证和分析,澄清了一些误解和标本鉴定的错误,论证了金钟藤变种黄毛金钟藤在中国仅产于广西,而云南产的黄毛金钟藤实为铜钟藤,并把Merremia biosiana var.sumatrana van Ooststr.作黄毛金钟藤的新异名处理。
