Effects of phosphorus-deficiency stress on ethylene emission in Asparagus bean

صينى. 探讨乙烯在长豇豆幼苗耐缺磷胁迫中的作用。选用3个耐缺磷程度不同的长豇豆品种芦花白（耐缺磷）、香港青（中间类型）、二芦白（不耐缺磷），采用水培方式，设置供磷（＋P）和缺磷（－P）2个处理，研究其幼苗各部分在缺磷胁迫下乙烯产生量的变化。缺磷胁迫下长豇豆幼苗根系乙烯产生量升高，升幅芦花白香港青二芦白；老茎叶乙烯产生量升高，升幅二芦白香港青芦花白；最嫩完全展开叶乙烯产生量也升高，其中升幅芦花白二芦白香港青；嫩茎叶乙烯产生量有变化，但幅度较小。缺磷胁迫下长豇豆幼苗根系和老茎叶乙烯产生量升高可能导致植物根系和茎形态结构的变化，增强植物获取磷的能力和根系清除活性氧的能力，增强了植株对水分和养分的吸收运输能力，从而增强适应缺磷胁迫的能力。

إنجليزي. To probe the role of ethylene in asparagus bean [Vigna unquiculata W. ssp. sesquipedalis (L.) Verd] response to phosphorus-deficiency stress. Changes of ethylene emission in seedlings of 3 asparagus bean cultivars differing in tolerance to phosphorus-deficiency were studied in 2 treatments (+P and -P) in soilless-culture experiment. Ethylene emission in asparagus bean seedling increased under P-deficiency stress. The increase of ethylene emission in root of cv. Luhuabai (high P-deficiency-tolerance) cv. Xianggangqing (middle P-deficiency-tolerance) cv. Erlubai (low P-deficiency-tolerance). The increase of ethylene emission in older leaf and stem of cv. Erlubaicv. Xianggangqing cv. Luhuabai. The increase of ethylene emission in youngest fully-expanded leaf of cv. Luhuabai cv. Erlubaicv. Xianggangqing. There was a little increase of ethylene emission in younger leaf and stem. The results indicated that the increase of ethylene emission in asparagus bean root and older stem and leaf might induced morphological changes in root and stem under phosphorus deficiency stress, then enhanced the ability of phosphorus acquisition and free radical scavenging in root, enhanced translocation of nutrient and water, thus enhanced the adaptability of asparagus bean seedlings to phosphorus deficiency stress .