Seed size influences the promoting activity of rhizobia on plant growth, nodulation and N fixation in lima bean

ABSTRACT: This study evaluated the activity of rhizobia isolates inoculated in large (18 mm) and small (11 mm) seeds on lima bean growth, nodulation and N fixation. Selected rhizobia isolates were compared with a reference strain CIAT899 and two controls without inoculation. Large seeds contributed for highest plant growth, nodulation and N fixation than small seeds. The isolates UFPI-59, UFPI-18 and UFPI-38 promoted the highest values of shoot and root dry weight, respectively. The isolates UFPI-32 promoted the highest values of nodule number, while UFPI-59 promoted the highest values of nodule dry weight. The isolates UFPI-38 and UFPI-59 promoted the highest accumulation of N. This study showed that seed size really influences lima bean growth, nodulation and BNF. Considering rhizobia isolates, UFPI-59, UFPI-38, and UFPI-18 contributed for plant growth, promoted better nodulation and effectiveness on biological N fixation.

摘要：本研究针对接种于大粒（18 mm）与小粒（11 mm）利马豆种子的根瘤菌分离菌株，评估其对利马豆生长、结瘤与固氮（Nitrogen Fixation）的影响。本研究将筛选获得的根瘤菌分离菌株与参比菌株CIAT899，以及两个未接种的对照组进行对比。相较于小粒种子，大粒种子可促使利马豆获得更高的植株生长量、结瘤水平与固氮效率。分离菌株UFPI-59、UFPI-18与UFPI-38分别可使植株地上部与地下部干重达到最高值。分离菌株UFPI-32可使根瘤数量达到最高，而UFPI-59可使根瘤干重达到最高。分离菌株UFPI-38与UFPI-59可使植株氮积累量达到最高水平。本研究证实，种子尺寸确实会对利马豆的生长、结瘤与生物固氮（Biological Nitrogen Fixation, BNF）产生显著影响。就根瘤菌分离菌株而言，UFPI-59、UFPI-38与UFPI-18可有效促进利马豆植株生长，优化结瘤效果并提升生物固氮效率。