A lipopeptide-producing bacterium, Bacillus cereus (F-6), was isolated from the rhizosphere soil of a healthy vanilla (Vanilla planifolia) plant cultivated on a plantation under 21 years of continuous cropping with va...A lipopeptide-producing bacterium, Bacillus cereus (F-6), was isolated from the rhizosphere soil of a healthy vanilla (Vanilla planifolia) plant cultivated on a plantation under 21 years of continuous cropping with vanilla. A pot experiment was conducted to investigate the effects of the green fluorescent protein-tagged F-6 (F-6-gfp) and its bio-organic fertilizer (BIO) on vanilla plant growth and stem and root rot disease, using the same plantation soil. The application of BIO significantly increased the vanilla plant root, stem and leave dry weights;however, there was not a significant difference between the F-6-gfp-inoculated treatment and the control. Meanwhile, the BIO application also significantly reduced the severity of stem and root rot disease compared to the control. The rhizosphere soil population of Fusarium was approximately 10-fold smaller in the BIO treatment compared to the control treatment at 150 days after transplantation. The number of B. cereus F-6-gfp in the rhizosphere soil of the BIO treatment remained significantly higher than that of the F-6-gfp-inoculated treatment throughout the experiment. In conclusion, F-6-gfp successfully colonized the rhizosphere soil in the BIO treatment, promoting vanilla plant growth, reducing the disease severity index, and decreasing the Fusarium population number, helping to remove barriers to the continuous cropping of vanilla.展开更多
The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction po...The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction potential following a three-month treatment with 6-benzylaminopurine (BAP) and α-Naphthaleneacetic acid (NAA). Results indicated that the shoot apices were poor candidates for shoot induction whereas the stem nodal segments showed potential for shoot initiation at a rate of up to 6 shoots/explant. Stem nodal segments were the most responsive as shoots formed (55 shoots) directly following treatments with 1 mg/L BAP at half strength MS medium after the third subculture. In addition, more shoots were produced on solid medium treatments compared to the liquid medium treatments in two strengths of mediums tested. Regenerated plantlets derived from the 1 mg/L of BAP treatment were induced to root following a one month culture in growth regulator-free MS medium. There was 90% survival rate of the rooted plantlets after acclimatization in the greenhouse. The findings in the present study would be helpful for large-scale mass propagation of Vanilla planifolia using this simple and efficient protocol.展开更多
文摘A lipopeptide-producing bacterium, Bacillus cereus (F-6), was isolated from the rhizosphere soil of a healthy vanilla (Vanilla planifolia) plant cultivated on a plantation under 21 years of continuous cropping with vanilla. A pot experiment was conducted to investigate the effects of the green fluorescent protein-tagged F-6 (F-6-gfp) and its bio-organic fertilizer (BIO) on vanilla plant growth and stem and root rot disease, using the same plantation soil. The application of BIO significantly increased the vanilla plant root, stem and leave dry weights;however, there was not a significant difference between the F-6-gfp-inoculated treatment and the control. Meanwhile, the BIO application also significantly reduced the severity of stem and root rot disease compared to the control. The rhizosphere soil population of Fusarium was approximately 10-fold smaller in the BIO treatment compared to the control treatment at 150 days after transplantation. The number of B. cereus F-6-gfp in the rhizosphere soil of the BIO treatment remained significantly higher than that of the F-6-gfp-inoculated treatment throughout the experiment. In conclusion, F-6-gfp successfully colonized the rhizosphere soil in the BIO treatment, promoting vanilla plant growth, reducing the disease severity index, and decreasing the Fusarium population number, helping to remove barriers to the continuous cropping of vanilla.
文摘The present study describes a direct shoot regeneration-based micropropagation procedure for Vanilla planifolia. Two types of explant (i.e. shoot apex and stem nodal segment) were screened for their shoot induction potential following a three-month treatment with 6-benzylaminopurine (BAP) and α-Naphthaleneacetic acid (NAA). Results indicated that the shoot apices were poor candidates for shoot induction whereas the stem nodal segments showed potential for shoot initiation at a rate of up to 6 shoots/explant. Stem nodal segments were the most responsive as shoots formed (55 shoots) directly following treatments with 1 mg/L BAP at half strength MS medium after the third subculture. In addition, more shoots were produced on solid medium treatments compared to the liquid medium treatments in two strengths of mediums tested. Regenerated plantlets derived from the 1 mg/L of BAP treatment were induced to root following a one month culture in growth regulator-free MS medium. There was 90% survival rate of the rooted plantlets after acclimatization in the greenhouse. The findings in the present study would be helpful for large-scale mass propagation of Vanilla planifolia using this simple and efficient protocol.
