Verticillium wilt caused by Verticillium dahliae is a threatening disease of cotton, causing economic loss worldwide. In this study, nine endophytic Bacillus strains isolated from cotton roots exhibited inhibitory activity against V. dahliae strain VD-080 in a dual culture assay. B. altitudinis HNH7 and B. velezensis HNH9 were chosen for further experiments based on their high antagonistic activity. The secondary metabolites of HNH7 and HNH9 also inhibited the growth of VD-080. Genetic marker-assisted detection revealed the presence of bacillibactin, surfactin, bacillomycin and fengycin encoding genes in the genome of HNH7 and HNH9 and their corresponding gene products were validated through LC-MS. Scanning electron microscopy revealed mycelial disintegration, curling and shrinkage of VD-080 hyphae after treatment with methanolic extracts of the isolated endophytes. Furthermore, a significant reduction in verticillium wilt severity was noticed in cotton plants treated with HNH7 and HNH9 as compared to control treatments. Moreover, the expression of defense-linked genes, viz., MPK3, GST, SOD, PAL, PPO and HMGR, was considerably higher in plants treated with endophytic Bacillus strains and inoculated with VD-080 as compared to control.

Aims:The potential of endophytic Bacillus strains to improve plant growth and yield was evaluated. Methods and results: Endophytic Bacillus altitudinis HNH7 and Bacillus velezensisHNH9 were evaluated for their growth-promoting traits. In an in vitro plate assay, HNH7 and HNH9 exhibited proteolytic, amylolytic, lipolytic and cellulolytic activity.HNH7 and HNH9 were able to solubilize iron by producing siderophores but were unable to solubilize insoluble phosphate. PCR confirmed the presence of four growthpromoting genes viz. pvd, budA, asbA and satA in the genome of HNH7, while HNH9 also possessed the same genes except for budA. In a greenhouse experiment, HNH7 and HNH9 promoted the growth of upland cotton plants by upregulating the expression of growth-linked genes, EXP6, ARF1, ARF18, IAA9, CKX6 and GID1b.However, the expression of genes involved in ethylene biosynthesis, that is ERF and ERF17 was downregulated after treating the plants with HNH7 and HNH9 compared to the control. Furthermore, cotton plants treated with HNH7 and HNH9 exhibited a significantly higher rate of photosynthesis and stomatal conductance. Conclusion:HNH7 and HNH9 showed a promising potential to promote the growth of cotton plants.Significance and impact of study: Research on plant growth-promoting Bacillus strains can lead to the formation of biofertilizers.

Popcorn is considered as one of the oldest forms of field corn and mainly used as a snack food. In the time being, no local popcorn registered hybrids are available in Egypt and all country needs are imported hybrids. Therefore, there is a dire need to develop local popcorn hybrids. Using local and exotic germplasm, eighty-six promising yellow F1- hybrids were developed at Nubaria research station (30°54' N, 29°30' E) maize program, Field Crops Research Institute, ARC, Egypt. These hybrids were split into two groups (A and B); each one along with two exotic hybrid checks were evaluated under irrigation in 2019 at two environmentally different locations, one in north of Egypt and the other one in south of Egypt. Purpose of this investigation was to evaluate these promising hybrids for grain yield, number of days to mid-silk, plant height, resistance to late wilt disease and two quality traits i.e. popping volume and percentage of unpopped kernels. Randomized complete block design with 4 replications was used. All technical recommendations for maize production were applied. Highly significant differences were found among tested hybrids for all studied traits except number of wilted plants in trial A. Seven hybrids were selected, 5 from trial A and two from trial B. Hybrids # 11, 12, 17, 20 and 28 from trial A and 15, 33 from trial B. Results revealed that germplasm of Serbian origin was more beneficial to the national popcorn breeding program than other germplasm sources since most selected hybrids were of Serbian origin. Further evaluation of selected hybrids across multiple different locations is necessary before submission of selected hybrids to Variety Registration Committee.