Endophytic fusarium solani exhibiting potential stress tolerance and enhances growth of maize in South Africa

Abstract

New technological approaches harness the potential of endophytic fungi as growth promoters, utilizing their bioactive compounds to protect against herbivores, insects, and various unfavourable abiotic stresses, including temperature, salinity, drought, and heavy metals. Zea mays (L.) is considered as a staple food source in many countries including South Africa. Endophytic fungi are natural growth promoters without causing any disease or symptoms of diseases. In the current study, nine endophytic fungi were examined for abiotic stress tolerance and were inoculated in the maize seeds prior to plantation. The construction of the phylogenetic tree was based on consensus sequences (ITS) using endophytic fungi produced three clades with four subgroups. Among the 9 endophytic fungi, only 3 fungal isolates (END 15, MHE 55, RNK 4) grew on 3% and 6% salinity PDA. Boeremia exigua was the only isolate that could withstand 6%. Fusarium solani (MHE 55) survived at low pH. Furthermore, Neurospora sp. (GG 9) and Fusarium solani (MHE 55) grew at 37 ºC. Greenhouse experiments were conducted to establish the growth promoting properties. The highest plant height was observed in the treatment which was inoculated with Fusarium oxysporum (GG 8) followed by Fusarium solani (MHE 55), reaching 46 cm and 44 cm respectively. The significant enhancement in plant height, root weight, fresh weight and leaf size, demonstrate the potential use of the selected isolate as a growth promoter for maize. In contrast Chaetomium (PG 9) and Alternaria (MHE 68) displayed none to limited growth promoting properties. To the best of our knowledge, this is the first report on the potential use of F. solani isolated from South African geranium as a growth promoter. As the world is aiming at a more sustainable and eco-friendly agriculture, the use of such endophytes will contribute to better crop production and protection, hence more food availability. Key words: Fusarium solani, Endophytes, Growth promotion, Maize, Stress tolerance, Boeremia exigua, Chaetomium, Alternaria