Phytoplasma host range and symptom expression in the pasture legume Stylosanthes

S De la rue, R Hopkinson, S Foster, Karen Gibb

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    A field trial of 23 stylo taxa was assessed for susceptibility to stylosanthes little leaf (SLL) disease. The trial included Stylosanthes scabra cw. Seca, Siran, and Fitzroy, S. guianensis var. guianensis cv. Cook, S. hamata cvv. Amiga and Verano and "Stylosanthes seabrana" cvv. Unica and Primar, as well as seven unreleased cultivars from a CSIRO anthracnose resistance breeding program, and four unreleased introduced lines. Plants that had SLL symptoms were sampled on six occasions from March to August 1999 and tested for phytoplasmas, the presumed causal organism of this disease, using the polymerase chain reaction (PCR). All taxa were found to be susceptible to SLL disease except 5. hamata cv. Verano and "S. seabrana" cv. Unica. Varieties were ranked on disease incidence, with S. scabra varieties bred for anthracnose resistance having the highest incidence of the disease. These varieties also had significantly higher SLL incidence than that of the original introductions from which they were derived. Before testing, symptom profiles were recorded noting the presence of chlorosis, spike elongation, reddening of leaf tips and floral parts, and reduced leaf size (little leaf). Statistical analysis of the association of these characteristics with SLL disease showed that little leaf was the best disease indicator and that chlorosis and excessive reddening of leaf tips and floral parts were also associated with the disease. The presence of floral abnormalities was also recorded in the symptom profiles. At no time were normal flowers found on samples that had SLL, making this symptom a good indicator of SLL. However, not all plants with floral symptoms tested positive for phytoplasmas by PCR, probably because these symptoms are difficult to diagnose visually. Virescence and phyllody were the most common floral abnormalities and were found to be associated specifically with the phytoplasmas pigeon pea little leaf and sweet potato little leaf variant V4, respectively. An additional floral abnormality, termed abortion, was also observed in association with this disease. � 2003 Elsevier Science B.V. All rights reserved.
    Original languageEnglish
    Pages (from-to)327-334
    Number of pages8
    JournalField Crops Research
    Volume84
    Issue number3
    Publication statusPublished - 2003

    Fingerprint

    phytoplasma
    Stylosanthes
    host range
    forage legumes
    Phytoplasma
    signs and symptoms (plants)
    pasture
    leaves
    foliar diseases
    Stylosanthes scabra
    abnormality
    anthracnose
    chlorosis
    Pigeon pea little leaf phytoplasma
    disease incidence
    polymerase chain reaction
    Stylosanthes hamata
    Stylosanthes guianensis
    abortion (plants)
    sweet potatoes

    Cite this

    De la rue, S ; Hopkinson, R ; Foster, S ; Gibb, Karen. / Phytoplasma host range and symptom expression in the pasture legume Stylosanthes. In: Field Crops Research. 2003 ; Vol. 84, No. 3. pp. 327-334.
    @article{1db4e2b753c74612ad0fccbc2379716a,
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    abstract = "A field trial of 23 stylo taxa was assessed for susceptibility to stylosanthes little leaf (SLL) disease. The trial included Stylosanthes scabra cw. Seca, Siran, and Fitzroy, S. guianensis var. guianensis cv. Cook, S. hamata cvv. Amiga and Verano and {"}Stylosanthes seabrana{"} cvv. Unica and Primar, as well as seven unreleased cultivars from a CSIRO anthracnose resistance breeding program, and four unreleased introduced lines. Plants that had SLL symptoms were sampled on six occasions from March to August 1999 and tested for phytoplasmas, the presumed causal organism of this disease, using the polymerase chain reaction (PCR). All taxa were found to be susceptible to SLL disease except 5. hamata cv. Verano and {"}S. seabrana{"} cv. Unica. Varieties were ranked on disease incidence, with S. scabra varieties bred for anthracnose resistance having the highest incidence of the disease. These varieties also had significantly higher SLL incidence than that of the original introductions from which they were derived. Before testing, symptom profiles were recorded noting the presence of chlorosis, spike elongation, reddening of leaf tips and floral parts, and reduced leaf size (little leaf). Statistical analysis of the association of these characteristics with SLL disease showed that little leaf was the best disease indicator and that chlorosis and excessive reddening of leaf tips and floral parts were also associated with the disease. The presence of floral abnormalities was also recorded in the symptom profiles. At no time were normal flowers found on samples that had SLL, making this symptom a good indicator of SLL. However, not all plants with floral symptoms tested positive for phytoplasmas by PCR, probably because these symptoms are difficult to diagnose visually. Virescence and phyllody were the most common floral abnormalities and were found to be associated specifically with the phytoplasmas pigeon pea little leaf and sweet potato little leaf variant V4, respectively. An additional floral abnormality, termed abortion, was also observed in association with this disease. � 2003 Elsevier Science B.V. All rights reserved.",
    keywords = "Cultivation, Diseases, Plants (botany), Statistical methods, Tissue, Polymerase chain reaction (PCR), Crops, breeding, cultivar, disease resistance, legume, pasture, Cajanus cajan, Columba, Ipomoea batatas, Phytoplasma, Pisum sativum, Solanum tuberosum, Stylosanthes, Stylosanthes guianensis, Stylosanthes hamata, Stylosanthes scabra, Stylosanthes seabrana, Uncia",
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    De la rue, S, Hopkinson, R, Foster, S & Gibb, K 2003, 'Phytoplasma host range and symptom expression in the pasture legume Stylosanthes', Field Crops Research, vol. 84, no. 3, pp. 327-334.

    Phytoplasma host range and symptom expression in the pasture legume Stylosanthes. / De la rue, S; Hopkinson, R; Foster, S; Gibb, Karen.

    In: Field Crops Research, Vol. 84, No. 3, 2003, p. 327-334.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Phytoplasma host range and symptom expression in the pasture legume Stylosanthes

    AU - De la rue, S

    AU - Hopkinson, R

    AU - Foster, S

    AU - Gibb, Karen

    PY - 2003

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    N2 - A field trial of 23 stylo taxa was assessed for susceptibility to stylosanthes little leaf (SLL) disease. The trial included Stylosanthes scabra cw. Seca, Siran, and Fitzroy, S. guianensis var. guianensis cv. Cook, S. hamata cvv. Amiga and Verano and "Stylosanthes seabrana" cvv. Unica and Primar, as well as seven unreleased cultivars from a CSIRO anthracnose resistance breeding program, and four unreleased introduced lines. Plants that had SLL symptoms were sampled on six occasions from March to August 1999 and tested for phytoplasmas, the presumed causal organism of this disease, using the polymerase chain reaction (PCR). All taxa were found to be susceptible to SLL disease except 5. hamata cv. Verano and "S. seabrana" cv. Unica. Varieties were ranked on disease incidence, with S. scabra varieties bred for anthracnose resistance having the highest incidence of the disease. These varieties also had significantly higher SLL incidence than that of the original introductions from which they were derived. Before testing, symptom profiles were recorded noting the presence of chlorosis, spike elongation, reddening of leaf tips and floral parts, and reduced leaf size (little leaf). Statistical analysis of the association of these characteristics with SLL disease showed that little leaf was the best disease indicator and that chlorosis and excessive reddening of leaf tips and floral parts were also associated with the disease. The presence of floral abnormalities was also recorded in the symptom profiles. At no time were normal flowers found on samples that had SLL, making this symptom a good indicator of SLL. However, not all plants with floral symptoms tested positive for phytoplasmas by PCR, probably because these symptoms are difficult to diagnose visually. Virescence and phyllody were the most common floral abnormalities and were found to be associated specifically with the phytoplasmas pigeon pea little leaf and sweet potato little leaf variant V4, respectively. An additional floral abnormality, termed abortion, was also observed in association with this disease. � 2003 Elsevier Science B.V. All rights reserved.

    AB - A field trial of 23 stylo taxa was assessed for susceptibility to stylosanthes little leaf (SLL) disease. The trial included Stylosanthes scabra cw. Seca, Siran, and Fitzroy, S. guianensis var. guianensis cv. Cook, S. hamata cvv. Amiga and Verano and "Stylosanthes seabrana" cvv. Unica and Primar, as well as seven unreleased cultivars from a CSIRO anthracnose resistance breeding program, and four unreleased introduced lines. Plants that had SLL symptoms were sampled on six occasions from March to August 1999 and tested for phytoplasmas, the presumed causal organism of this disease, using the polymerase chain reaction (PCR). All taxa were found to be susceptible to SLL disease except 5. hamata cv. Verano and "S. seabrana" cv. Unica. Varieties were ranked on disease incidence, with S. scabra varieties bred for anthracnose resistance having the highest incidence of the disease. These varieties also had significantly higher SLL incidence than that of the original introductions from which they were derived. Before testing, symptom profiles were recorded noting the presence of chlorosis, spike elongation, reddening of leaf tips and floral parts, and reduced leaf size (little leaf). Statistical analysis of the association of these characteristics with SLL disease showed that little leaf was the best disease indicator and that chlorosis and excessive reddening of leaf tips and floral parts were also associated with the disease. The presence of floral abnormalities was also recorded in the symptom profiles. At no time were normal flowers found on samples that had SLL, making this symptom a good indicator of SLL. However, not all plants with floral symptoms tested positive for phytoplasmas by PCR, probably because these symptoms are difficult to diagnose visually. Virescence and phyllody were the most common floral abnormalities and were found to be associated specifically with the phytoplasmas pigeon pea little leaf and sweet potato little leaf variant V4, respectively. An additional floral abnormality, termed abortion, was also observed in association with this disease. � 2003 Elsevier Science B.V. All rights reserved.

    KW - Cultivation

    KW - Diseases

    KW - Plants (botany)

    KW - Statistical methods

    KW - Tissue

    KW - Polymerase chain reaction (PCR)

    KW - Crops

    KW - breeding

    KW - cultivar

    KW - disease resistance

    KW - legume

    KW - pasture

    KW - Cajanus cajan

    KW - Columba

    KW - Ipomoea batatas

    KW - Phytoplasma

    KW - Pisum sativum

    KW - Solanum tuberosum

    KW - Stylosanthes

    KW - Stylosanthes guianensis

    KW - Stylosanthes hamata

    KW - Stylosanthes scabra

    KW - Stylosanthes seabrana

    KW - Uncia

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    M3 - Article

    VL - 84

    SP - 327

    EP - 334

    JO - Field Crops Research

    JF - Field Crops Research

    SN - 0378-4290

    IS - 3

    ER -