阔叶丰花草与果园几种常见杂草的生理生态特性比较

Comparison of Physiological and Ecological Characteristics Between Borreria latifolia and Several Common Orchard Weeds

【目的】阔叶丰花草是华南地区果园生草的适宜植物,明确阔叶丰花草与果园几种常见杂草的生理生态特性。【方法】比较阔叶丰花草与常见杂草藿香蓟、白花鬼针草和牛筋草之间种子形态及发芽特征、根系特征、光合特征以及对草甘膦敏感性的差异。【结果】阔叶丰花草种子千粒质量为藿香蓟、白花鬼针草和牛筋草的1.8~25.8倍,同时阔叶丰花草的种子发芽率也较高,幼苗生长速度也较快。阔叶丰花草植株的根冠比比其他3种草低70.1%~79.3%,但在其根系中,直径为0~0.5 mm的细根所占比重(87.8%)较其他3种草高16.3%~21.6%。在4种草中,阔叶丰花草的光合强度最小,其净光合速率(Pn)分别比藿香蓟、白花鬼针草和牛筋草低22.9%、34.3%和64.3%;而其蒸腾速率(Tr)和气孔导度(gs)均介于牛筋草和其他两种草之间。阔叶丰花草对草甘膦的敏感性低于藿香蓟和白花鬼针草,其ED50分别为藿香蓟和白花鬼针草的3.75、1.79倍。【结论】阔叶丰花草具有幼苗快速生长、浅根系、低光合强度和耐草甘膦的特性。

【Objective】Borreria latifolia is suitable for green covering in the orchards of south China.The study is conducted to elucidate the physiological and ecological characteristics of B.latifolia and several common orchard weeds.【Method】The differences in seed morphology and germination characteristics,root characteristics,photosynthetic characteristics,and sensitivity to glyphosate between B.latifolia and three common weeds,Ageratum conyzoides,Bidens alba and Eleusine indica,were compared.【Result】The thousand seed weight of B.latifolia was 1.8-25.8 times than that of A.conyzoides,B.alba and E.indica.Meanwhile,seed germination rate of B.latifolia was greater than that of other weeds,and seedling growth of B.latifolia was also faster.The root-shoot ratio of B.latifolia was 70.1%-79.3%lower than that of other weeds.However,the diameter frequency(87.8%)of its root system in the range of 0-0.5 mm was 16.3%-21.6%higher than that of the other three weeds.Among the four species,B.latifolia had the lowest photosynthetic intensity,and its net photosynthetic rate(Pn)was 22.9%,34.3%,and 64.3%lower than that of A.conyzoides,B.alba and E.indica,respectively,while its transpiration rate(Tr)and stomatal conductance(gs)were lower than those of A.conyzoides and B.alba,but higher than those of E.indica.B.latifolia was less sensitive to glyphosate than A.conyzoides and B.alba,and the 50%effective dose(ED50)of glyphosate on B.latifolia was 3.74 and 1.79 times of A.conyzoides and B.alba,respectively.【Conclusion】The characteristics of B.latifolia are fast growth ability at the seedling stage,shallow roots,low photosynthetic rates and glyphosate tolerance.