Clonostachys rosea (syn. Gliocladium roseum) IK726 was originally selected as an effective biocontrol agent (BCA) against cereal seed borne diseases caused by Fusarium culmorum and Bipolaris sorokiniana. We have studi...Clonostachys rosea (syn. Gliocladium roseum) IK726 was originally selected as an effective biocontrol agent (BCA) against cereal seed borne diseases caused by Fusarium culmorum and Bipolaris sorokiniana. We have studied the efficacy of the antagonist against different pathogens in several crops and found that the antagonist also is able to control Alternaria radicina and A. dauci on carrot seeds and different cold-storage fungi in acorns. IK726 is also able to reduce severity of soil borne Pythium spp. in cabbage, carrot and sugar beet. In addition, growth-promoting effects of IK726 have been demonstrated in barley and tomato. In order to develop and improve application methods and control strategies, essential basic studies of ecology and the mechanisms of control of IK726 is needed and has led us to use various molecular tools. The UP-PCR technology is used for strain recognition and we have developed GUS and GFP-transformants that resembles the wildtype strain in ecological fitness parameters. Using either the GUS-transformant or UP-PCR we have found that IK726, when applied with seeds, reproduces and survives several months in the rhizosphere of field grown barley and carrot. The GFP-transformant is used to study the behavior and in situ interactions of the antagonist with pathogens and plants. Using the GFP marker, we have observed conidial germination, colonization and conidiogenesis in natural soil, in vermiculite and on carrot and barley seed and roots and on barley leaves. Moreover in situ interactions with Alternaria on carrot material have been studied. The modes of action of C. rosea are not well understood but enzymatic activity, mycoparasitism, substrate competition, antibiosis and induced resistance are thought to play a role. Barley treated with C. rosea IK726 has an enhanced chitinolytic and glucanolytic activity compared to the activity in non-treated barley in pot experiments with field soil. Identification of chitinases from IK726 and studies of their role in interactions with pathogens have t展开更多
Universally Primed PCR (UP-PCR) is a PCR fingerprinting method that has demonstrated its applicability in different aspects of mycology. These applications constitute analysis of genome structures, identification of s...Universally Primed PCR (UP-PCR) is a PCR fingerprinting method that has demonstrated its applicability in different aspects of mycology. These applications constitute analysis of genome structures, identification of species, analysis of population and species diversity, revealing of genetic relatedness at infra-and inter-species level, and identification of UP-PCR markers at different taxonomic levels (strain, group and/or species) . A further development of the UP-PCR technique is an UP-PCR product cross hybridisation assay that facilitates investigation of sequence similarity (homology) of UP-PCR products and grouping of strains into UP-PCR hybridisation groups. This separates the strains into entities with high genetic similarity (DNA homology) . UP-PCR has been used as an aid in taxonomy and species delineation, and to monitor biocontrol strains following their release into the environment by fingerprint characterisation of pure cultures and through direct detection in soil by amplification of UP-PCR-derived SCAR markers. The technique has been applied to Trichoderma strains in particularly with the aims of strain recognition and classification.展开更多
文摘Clonostachys rosea (syn. Gliocladium roseum) IK726 was originally selected as an effective biocontrol agent (BCA) against cereal seed borne diseases caused by Fusarium culmorum and Bipolaris sorokiniana. We have studied the efficacy of the antagonist against different pathogens in several crops and found that the antagonist also is able to control Alternaria radicina and A. dauci on carrot seeds and different cold-storage fungi in acorns. IK726 is also able to reduce severity of soil borne Pythium spp. in cabbage, carrot and sugar beet. In addition, growth-promoting effects of IK726 have been demonstrated in barley and tomato. In order to develop and improve application methods and control strategies, essential basic studies of ecology and the mechanisms of control of IK726 is needed and has led us to use various molecular tools. The UP-PCR technology is used for strain recognition and we have developed GUS and GFP-transformants that resembles the wildtype strain in ecological fitness parameters. Using either the GUS-transformant or UP-PCR we have found that IK726, when applied with seeds, reproduces and survives several months in the rhizosphere of field grown barley and carrot. The GFP-transformant is used to study the behavior and in situ interactions of the antagonist with pathogens and plants. Using the GFP marker, we have observed conidial germination, colonization and conidiogenesis in natural soil, in vermiculite and on carrot and barley seed and roots and on barley leaves. Moreover in situ interactions with Alternaria on carrot material have been studied. The modes of action of C. rosea are not well understood but enzymatic activity, mycoparasitism, substrate competition, antibiosis and induced resistance are thought to play a role. Barley treated with C. rosea IK726 has an enhanced chitinolytic and glucanolytic activity compared to the activity in non-treated barley in pot experiments with field soil. Identification of chitinases from IK726 and studies of their role in interactions with pathogens have t
文摘Universally Primed PCR (UP-PCR) is a PCR fingerprinting method that has demonstrated its applicability in different aspects of mycology. These applications constitute analysis of genome structures, identification of species, analysis of population and species diversity, revealing of genetic relatedness at infra-and inter-species level, and identification of UP-PCR markers at different taxonomic levels (strain, group and/or species) . A further development of the UP-PCR technique is an UP-PCR product cross hybridisation assay that facilitates investigation of sequence similarity (homology) of UP-PCR products and grouping of strains into UP-PCR hybridisation groups. This separates the strains into entities with high genetic similarity (DNA homology) . UP-PCR has been used as an aid in taxonomy and species delineation, and to monitor biocontrol strains following their release into the environment by fingerprint characterisation of pure cultures and through direct detection in soil by amplification of UP-PCR-derived SCAR markers. The technique has been applied to Trichoderma strains in particularly with the aims of strain recognition and classification.
