Intergenerational benefits of microbial priming on performance of finger millet against parasitic- nematodes

Abstract

Finger millet (Eleusine coracana L.) is an important staple grain crop that contributes significantly to food security and income. It’s grown in semi-arid areas. However, the production of finger millet is constrained by conditions of low soil fertility and root- knot nematodes (Meloidogyne javanica). Beneficial soil microbes provide an alternative and potentially sustainable option for farmers, showing promise in enhancing plant growth and resistance, and these benefits can be pass down through generations creating intergenerational effects. The broad objective of this study is to contribute towards increased finger millet yields through intergenerational priming effects of efficacious Bacillus amyloliquefaciens, Purpureocillium lilacinum, and Trichoderma asperellum. Finger millet plants were grown for two generations. In the first generation, finger millet plants were inoculated with the respective microbes, and their growth and yield parameters evaluated. Seeds harvested from these microbe- primed plants were then used to establish a second generation, which was grown without additional microbial inoculation. These second-generation plants were challenged with M. javanica to assess intergenerational acquired resistance and growth potential. The results indicated that seeds from B. amyloliquefaciens inoculated plants showed improved grain weight (p < 0.05) of 83.2% in the second generation. P. lilacinum resulted in grain weight increase by 41% while T. asperellum did not increase grain weight. Plants treated with B. amyloliquefaciens and P. lilacinum in the previous generation resulted in significantly reduced M. javanica infection in their progeny from 407.5 J2 (g soil) −1 to 222.5 J2 (g soil) −1 and 170 J2 (g soil) −1, respectively. This study demonstrates that microbial priming, particularly with B. amyloliquefaciens, not only promotes growth and yield but also induces acquired resistance to root-knot nematodes in finger millet. These findings offer promising insights into the development of sustainable and eco-friendly strategies for enhancing crop resilience and productivity through natural plant-microbe interactions. Microbial seed priming using Bacillus amyloliquefaciens and Purpureocillium lilacinum should be promoted to enhance finger millet growth and nematode resistance. Further multi-location and multi-season studies are needed to confirm field effectiveness and support adoption by farmers.