Research output per year
Research output per year
Mahtab Omidvari, Gavin R. Flematti, Ming Pei You, Payman Abbaszadeh Dahaji, Martin J. Barbetti
Research output: Contribution to journal › Article › peer-review
Phoma black stem and leaf spot disease of annual Medicago spp., caused by Phoma medicaginis, not only can devastate forage and seed yield but can reduce herbage quality by inducing production of phytoes-trogens (particularly coumestrol and 49-O-methylcoumestrol), which can also reduce the ovulation rates of animals grazing infected forage. We determined the consequent phytoestrogen levels on three different annual Medicago species/cultivars (Medicago truncatula cultivar Cyprus, Medicago polymorpha var. brevispina cultivar Serena, and Medicago murex cultivar Zodiac) after inoculation with 35 isolates of P. medicaginis. Across the isolate × cultivar combinations, leaf disease incidence, petiole/stem disease incidence, leaf disease severity, petiole disease severity, and leaf yellowing severity ranged up to 100, 89.4, 100, 58.1, and 61.2%, respectively. Cultivars Cyprus and Serena were the most susceptible and cultivar Zodiac was the most resistant to P. medicaginis. Isolates WAC3653, WAC3658, and WAC4252 produced the most severe disease. Levels of phytoestrogens in stems ranged from 25 to 1,995 mg/kg for coumestrol and from 0 to 418 mg/kg for 49-O-methylcoumestrol. There was a significant positive relationship of disease incidence and severity parameters with both coumestrol and 49-O-methylcoumestrol contents, as noted across individual culti-vars and across the three cultivars overall, where r = 0.39 and 0.37 for coumestrol and 49-O-methylcoumestrol, respectively (P 0.05). Although cultivar Serena was most susceptible to P. medicaginis and produced the highest levels of phytoestrogens in the presence of P. medicaginis, cultivar Zodiac contained the highest levels of phytoestro-gens in comparison with other cultivars in the absence of P. medicagi-nis. There was a 15-fold increase in coumestrol in cultivar Serena but only a 7-fold increase in cultivar Zodiac from infection of P. medicagi-nis. The study highlights that the intrinsic ability of a particular cultivar to produce phytoestrogens in the absence of the pathogen, and its comparative ability to produce phytoestrogens in the presence of the P. medicaginis, are both important and highly relevant to developing new annual Medicago spp. cultivars that offer improved disease resis-tance and better animal reproductive outcomes.
Original language | English |
---|---|
Journal | Plant Disease |
Volume | 105 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2021 |
Research output: Thesis › Doctoral Thesis