Braunberger P G, Miller M H, Peterson R L
Department of Land Resource Science, University of Guelph, Guelph, Ontario, NIG 2W1, Canada.
Department of Botany, University of Guelph, Guelph, Ontario, NIG 2W1, Canada.
New Phytol. 1991 Sep;119(1):107-113. doi: 10.1111/j.1469-8137.1991.tb01013.x.
The morphology of the colonization of maize (Zea mays L.) by the vesicular arbuscular mycorrhizal fungus Glomus versiforme (Daniels and Trappe) Berch was determined quantitatively to establish the stage at which colonization was limited in response to increased P nutrition. Harvests were taken 14, 19, 24 and 29 d after planting maize in a calcined clay medium to which nutrient solution containing 0.16, 0.8 or 2.4 mM P was added daily. The fraction of the root length containing arbuscules (FAC) 19 d after planting was 0.4 with 0.16 mM P, 0.3, with 0.8 mM P and 0.17 with 2.4 mM P. Corresponding shoot P concentrations were 1.5, 2.0 and 3.2 mg g . Increased shoot P concentration reduced the number of appressoria per unit root length, but this accounted for only a part of the reduction in FAC. Increased root length did not account for the effect of shoot P concentration on FAC. The length of arbuscular colonized root length (total root length × FAC) per appressorium was strongly reduced in response to increased shoot P concentration. It was concluded that the reduction in FAC was mediated primarily through an inhibition of intra-radical development.
对泡囊丛枝菌根真菌地表球囊霉（Daniels和Trappe）Berch在玉米（Zea mays L.）上的定殖形态进行了定量测定，以确定在磷营养增加时定殖受限的阶段。在煅烧粘土培养基中种植玉米后14、19、24和29天进行收获，每天向该培养基中添加含0.16、0.8或2.4 mM磷的营养液。种植后19天，含丛枝的根长度分数（FAC）在磷浓度为0.16 mM时为0.4，0.8 mM时为0.3，2.4 mM时为0.17。相应的地上部磷浓度分别为1.5、2.0和3.2 mg g。地上部磷浓度的增加降低了单位根长度上附着胞的数量，但这仅占FAC降低的一部分。根长度的增加并不能解释地上部磷浓度对FAC的影响。随着地上部磷浓度的增加，每个附着胞的丛枝定殖根长度（总根长度×FAC）显著降低。得出的结论是，FAC的降低主要是通过抑制根内发育介导的。
