【作者】 李剑峰； 张淑卿； 师尚礼； 霍平慧；

【Author】 LI Jian-feng~(1,2) ZHANG Shu-Qing~(1,2) SHI Shang-li~(1,2) Huo Ping-hui~(1,2) (1.College of Grassland Science,Gansu Agricultural University,Lanzhou,730070;2.Key Laboratory of Grassland Ecosystem of Ministry of Education/Sino-U.S.Centers for Grazing land Ecosystem Sustainability, 730070)

【机构】 甘肃农业大学草业学院； 草业生态系统教育部重点实验室/中—美草地畜牧业可持续发展研究中心；

【摘要】 有效磷的缺乏是紫花苜蓿在缺磷地区栽培的限制因素,影响植株的生长和根瘤的形成。以砂培盆栽试验模拟低磷胁迫(仅提供磷酸钙)的栽培条件,分别以接种无溶磷能力的苜蓿根瘤菌12531,施入完全营养液(CK2)和不接种根瘤菌亦不施可溶性磷的处理(CK1)作为对照,评价溶磷苜蓿根瘤菌LW107(Rhizobium meliloti.)和溶磷红豆草根瘤菌RSW96(Rhizobium sp.)对金皇后苜蓿(Medicago sativa cv.Golden Empress)幼苗生长、结瘤和磷吸收的影响。结果表明,在仅提供难溶性无机磷的环境下,溶磷根瘤菌能促进苜蓿幼苗的生长、结瘤和生物量的积累。接种LW107的植株生物量较CK1和接种12531菌株的处理分别高出85.94%和36.78%,根瘤直径和根瘤同氮酶活性高出12531菌株57.3%和95.81%,植株全磷含量分别高出CK1和接种12531处理19.86%和10.27%,株高、根长和叶片数显著高于CK2(P<0.05);缺磷条件下,标准菌13531能侵染植株产生大量根瘤,但根瘤直径和根瘤固氮酶活性较低。在低有效磷环境下,溶磷根瘤菌对苜蓿幼苗的生长和结瘤的促进作用优于普通根瘤菌;在磷素充足时,植株自结瘤能力和根瘤的固氮酶活性高于缺磷条件下的植株。更多还原

【Abstract】 Available P deficiency is the main limiting factor that affects the formation of nodules as well as the growth for alfalfa cultivation in P poor regions.Experiments were designed to imitate low P stress(only phosphate calcium was offered) with sand culture and were inoculated with rhizobium 12531 which was incapable of solubilizing phosphorus.Treatments watered with full Hoagland’s solution were used as control group 2(CK2);treatments uninoculated with rhizobium and unapplied with soluble phosphorus were used as control group 1(CK1 ),and the effects of phosphorus solubilizing alfalfa rhizobium LW107(Rhizobium meliloti) and phosphorus solubilizing sainfoin rhizobium RSW96(Rhizobium sp.) on the growth,nodulation and biomass accumulation of alfalfa seedlings were assessed.The result indicated that the growth,nodulation and biomass accumulation of alfalfa seedlings were promoted on condition of hard solubilizing inorganic P be offered only. Biomass of seedlings that inoculated with LW107 was 85.94%and 36.78%times higher than CK1 and seedlings that inoculated with 12531,respectively;the nodules diameter and nitrogenase activity was 57.3%and 95.81% times higher than strain 12531;total P contents was 19.86%and 10.27%times higher than CK1 and treatments inoculated with 12531;and shoot height,root length and leaf number were found significantly higher that CK2 (P<0.05). On condition of P deficiency,standard strain 12531 was capable of infecting seedlings to produce mass nodules, but with lower mtrogenase activity and smaller diameter.Self-nodulation activity and nitrogenase activity of seedlings with sufficient P were found higher than those seedlings lack of phosphorus.更多还原