|Zhang, Jiuxu - TEXAS A&M UNIVERSITY|
|Starr, J - TEXAS A&M UNIVERSITY|
Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 21, 1995
Publication Date: N/A
Interpretive Summary: Treatment of cottonseed with latex sticker and biocontrol preparations of Gliocladium virens or Bacillus subtilis suppressed colonization of developing cotton roots by species of Fusarium and suppressed the incidence and severity of Fusarium wilt of cotton. The treatments did not affect the reproduction of Root Knot Nematode on the cotton root. These results may help to explain why treatment of cotton seeds with biocontrol agents often results in more vigorous plants with higher lint yields.
Technical Abstract: In a growth chamber at 25 C, the fungal antagonist Gliocladium virens colonized tap roots and secondary roots of cotton in non-sterile soil after seed treatment with preparations of G. virens. Colonization of tap roots by G. virens increased over time, and decreased with root depth. Seed treatments with G. virens strains G-4 and G-6 and with Bacillus subtilis strains GB03 and GB07 reduced the colonization of tap roots and secondary roots of cotton seedlings by Fusarium spp. Under greenhouse conditions, the same seed treatments suppressed the incidence and severity of fusarium wilt of cotton in soil infested with Fusarium oxysporum f. sp. vasinfectum and Meloidogyne incognita. Gliotoxin, produced by "Q-group" strains of G. virens, inhibited F. oxysporum f. sp. vasinfectum in vitro. The seed treatments with G. virens strain G-6 and B. subtilis strains GB03 and GB07 did not affect the reproduction of root-knot nematodes. The results of this study may help to explain why the treatment of cottonseed with biocontrol agents often results in more vigorous and higher yielding plants, and indicate that there is potential for using G. virens and B. subtilis as seed treatments to control fusarium wilt of cotton.