研究了不同长豇豆〔Vigna unquiculata W. ssp. sesquipedalis (L.)Verd〕品种幼苗在缺磷胁迫下的形态结构变化。结果表明:缺磷胁迫下,耐缺磷品种’芦花白’的叶片和海绵组织厚度增幅较大,栅栏组织厚度与海绵组织厚度的比值减小,气孔密度增幅较小;茎和茎导管直径增大,且比不耐缺磷的品种’二芦白’大;根直径变小,根量增加,这使其在缺磷胁迫下能保持较强的养分和水分吸收、输导能力和光合能力。缺磷胁迫下,长豇豆叶表皮气孔密度增大,气孔蒸腾加强,促进了水分和磷从根部向上运转及磷的被动吸收。不耐缺磷品种’二芦白’的气孔密度增加幅度较大,促进磷吸收运转的强度较大,为避免过多失水,栅栏组织厚度及栅栏组织与海绵组织厚度的比值增加较大,减弱了非气孔蒸腾的强度。

Changes of seedling anatomical structures of asparagus bean〔Vigna unquiculata W. ssp. sesquipedalis (L.) Verd〕 cultivars under phosphorus-deficiency stress were studied. Under P-deficiency stress, thickness of leaf and spongy tissue of`Luhuabai'(High P-deficiency-tolerance)plants increased more than that of `Erlubai' (LowP-deficiency-tolerance), densities of stomata increased less than `Erlubai', the ratio of thickness of palisade tissue and thickness of spongy tissue(P/S)decreased, diameter of stem and vessel increased and were larger than `Erlubai', root diameter decreased but root number increased. Thus there were stronger capability of absorption and translocation of nutrient, water and photosynthesis in `Luhuabai', then enhanced the tolerance to P-deficiency stress. Under P-deficiency stress, the increase of stoma densities enhanced transpiration, then enhanced translocation of water and phosphorus from root to shoot and passive absorption of phosphorus, that of `Erlubai' increased more, however, to avoid too much water-loss, thickness of palisade tissue and P/S increased more, thus non-stomata evaporation decreased.