Screening of rhizobacteria from rhizosphere of healthy chili to control bacterial wilt disease and to promote growth and yield of chili

Abstract

Abstract. Yanti Y, Astuti FF, Habazar T, Nasution CR. 2017. Screening of rhizobacteria from rhizosphere of healthy chili to control bacterial wilt disease and to promote growth and yield of chili. Biodiversitas 18: 1-9. Bacterial wilt on chili cause by Ralstonia solanacearum. This disease is important, causing plant death and significant yield losses. Biological control is desirable because control with other methods gives variable results. One of the important group of biological agent is the plant growth promoting rhizobacteria (PGPR). This group can control plant pathogens and enhance the growth and yield through direct and indirect mechanisms. The aim of this research was to obtain indigenous rhizobacterial isolates from rhizosphere of healthy chili, which are effective to control bacterial wilt disease and to promote plant growth as well as to increase plant yields. The rhizobacterial isolates were collected from healthy chili rhizosphere in endemic area of bacterial wilt at Banuhampu Sub-district, Agam District, West Sumatra, Indonesia. Screening method of rhizobacterial isolates to control bacterial wilt was based on in planta technique. This technique was consist of three steps, as follow: (i) Screening of 43 rhizobacterial isolates to induce the hypersensitive reaction on Mirabilis jalapa. (ii) Screening of 42 rhizobacterial isolates (from first step) to increase growth of chili seedlings and (iii) Screening of 20 selected rhizobacterial isolates (from second step) to control bacterial wilt on chili. R. solanacearum were inoculated on the 6 weeks chili plants using Two strains of rhizobacterial isolates from chili rhizosphere (RZ.2.1.AG1 and RZ.1.3.AP1) showed high potential for disease suppression and also increased growth and yield of chili.

Indigenous endophyte bacteria ability to control Ralstonia and Fusarium wilt disease on chili pepper

“…One pure colony of indigenous endophyte bacteria (IEB) isolates was added to 25mL of Tryptic Soy Broth (TSB, HiMedia®) in culture bottle (50mL) and was incubated in rotary shaker for 24 hours. 1 mL preculture was transferred to 150 mL of sterile coconut water in Erlenmeyer flask for main culture and was incubated for 2x24 hours (Yanti et al 2017). Suspension of IEB isolates from main culture was diluted with comparison to McFarland scale 8 (Density estimated 10 8 CFU/mL).…”

“…Our Previous study had screened 9 best endophyte bacteria isolates, which has potential to plant growth promotion (Yanti et al 2017). However, the ability of these strain to control pathogens is not identified, yet.…”

Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum

“…and their in vitro inhibition zones might be due to the activity of lytic enzymes like protease and the synthesis of antibiotics, which are the most common characteristics associated with PGPR (Mazurier et al 2009). Based on properties of strains, only little direct activities showed being related to biocontrol activity, whereas from previous research (Yanti et al 2017), all isolates showed the best biocontrol activity with no R. solanacearum symptoms appears. Based on these results, it could be concluded that most of all strains had ability in controlling R. solanacearum via indirectly mechanisms such as Induced Systemic Resistance (ISR).…”

“…The Hypersensitive reactions were done by infiltrating the Mirabilis jalapa leaves with 10 8 CFU/mL, which was acquired by comparing McFarland solutions in the scale of 8. The infiltrated leaves were then incubated for 48 hours (Yanti et al 2017). The occurrence of necrosis on the M. jalapa leaves indicated the positive HR reactions of Bacillus, which was suspected as pathogens so that it could not be used further.…”

“…Those abilities are very useful for commercial applications because it will provide long shelf life (Niazi et al 2014 Wulff et al 2002), Xanthomonas euvesicatoria and Xanthomonas perforans on tomato (Roberts et al 2008), X. campestris (now axonopodis) pv. glycines on soybean (Salerno and Sagardoy 2003), Ralstonia solanacearum on chili (Yanti et al 2017), mulberry (Ji et al 2008, and tobacco (Maketon et al 2008).…”