Hassan Mohammad K, McInroy John A, Jones Jarrod, Shantharaj Deepak, Liles Mark R, Kloepper Joseph W
Department of Entomology and Plant Pathology, Auburn University, CASIC Building, Auburn, AL 36849, USA.
Gulf Coast Research and Extension Center (GCREC), Fairhope, AL 36532, USA.
Plants (Basel). 2019 May 9;8(5):120. doi: 10.3390/plants8050120.
Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel (OP) amendments to (Bv) PGPR strains could increase soybean growth and nodulation by in greenhouse and field experiments to reduce variability. The treatments included untreated soybean seeds planted in field soil that contained Bv PGPR strains and non-inoculated controls with and without 0.1% () pectin or (1 or 10 mg/200 μL) orange peel (OP) amendment. In greenhouse and field tests, 35 and 55 days after planting (DAP), the plants were removed from pots, washed, and analyzed for treatment effects. In greenhouse trials, the rhizobial inoculant was not added with Bv strains and pectin or OP amendment, but in the field trial, a commercial inoculant was used with Bv strains and pectin amendment. In the greenhouse tests, soybean seeds inoculated with Bv AP193 and pectin had significantly increased soybean shoot length, dry weight, and nodulation by indigenous compared to AP193 without pectin. In the field trial, pectin with Bv AP193 significantly increased the shoot length, dry weight, and nodulation of a commercial compared to Bv AP193 without pectin. In greenhouse tests, OP amendment with AP193 at 10 mg significantly increased the dry weight of shoots and roots compared to AP193 without OP amendment. The results demonstrate that pectin-rich amendments can enhance Bv-mediated soybean growth promotion and nodulation by indigenous and inoculated .
促进植物生长的根际细菌（PGPR）在全球范围内越来越多地应用于农作物。虽然选定的PGPR菌株在可控的温室条件下能够反复促进植物生长，但其在田间的功效往往更具变异性。我们的总体目标是通过温室和田间试验来确定对慢生根瘤菌（Bv）PGPR菌株添加果胶或橙皮（OP）是否可以增加大豆生长和结瘤，以减少变异性。处理包括种植在含有Bv PGPR菌株的田间土壤中的未处理大豆种子以及添加和不添加0.1%（w/v）果胶或（1或10毫克/200微升）橙皮（OP）的未接种对照。在温室和田间试验中，种植后35天和55天（DAP），将植物从花盆中取出，冲洗并分析处理效果。在温室试验中，根瘤菌接种剂未与Bv菌株以及果胶或OP添加物一起使用，但在田间试验中，一种商业根瘤菌接种剂与Bv菌株和果胶添加物一起使用。在温室试验中，与未添加果胶的AP193相比，接种Bv AP193和果胶的大豆种子使大豆地上部长度、干重以及土著根瘤菌的结瘤显著增加。在田间试验中，与未添加果胶的Bv AP193相比，添加Bv AP193的果胶显著增加了一种商业根瘤菌的地上部长度、干重和结瘤。在温室试验中，与未添加OP的AP193相比，添加10毫克AP193的OP显著增加了地上部和根部的干重。结果表明，富含果胶的添加物可以增强Bv介导的大豆生长促进作用以及土著和接种根瘤菌的结瘤。
