Influence of Rhizobia Inoculation on Biomass Gain and Tissue Nitrogen Content of Leucaena leucocephala Seedlings under Drought

Forests

Gabriela Pereyra¹  Henrik Hartmann¹  Beate Michalzik³  Waldemar Ziegler¹  Susan Trumbore¹  Reynaldo Campos Santana² 

[1] Max Planck Institute for Biogeochemistry, Hans-Knöll-str. 10, 07745 Jena, Germany; E-Mails:Max Planck Institute for Biogeochemistry, Hans-Knöll-str. 10, 07745 Jena, Germany;;Institute of Geography, Faculty of Chemical and Earth Sciences, Friedrich-Schiller-Universität Jena, Löbdergraben 32, 07743 Jena, Germany; E-Mail:

关键词: symbiosis;    nodulation;    nitrogen fixation;    Rhizobium tropici;    Mesorhizobium loti;    reforestation;    ¹⁵N abundance;    agroforestry;   

DOI  :  10.3390/f6103686

来源: mdpi

【 摘 要 】

Anticipated increases in the frequency of heat waves and drought spells may have negative effects on the ability of leguminous trees to fix nitrogen (N). In seedlings of Leucaena leucocephala inoculated with Mesorhizobium loti or Rhizobium tropici, we investigated how the developmental stage and a short drought influenced overall biomass and the accumulation of carbon and N in plant tissues. In early developmental stages, the number of nodules and nodule biomass were correlated with total plant biomass and δ¹⁵N, and nodules and roots contributed 33%–35% of the seedling total N. Seedlings associated with R. tropici fixed more N and exhibited higher overall biomass compared with M. loti seedlings. Four and a half months after inoculation (140 days after inoculation, DAI), a short (15-day) drought inhibited seedling growth and caused a decline in total plant N, with the smallest decline in R. tropici seedlings. After 15 days of drought, i.e., 155 DAI, the nodules had accumulated proline, but the total amino acid concentration did not change. Our results indicate that N-fixation is independent of seedlings growth. In addition, R. tropici is a better choice than M. loti as a symbiont for Leucaena seedlings for forest restoration and agroforestry applications under increasingly drier conditions.

【 授权许可】

CC BY   
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