Host - parasite interaction reveals inter - and intraspecific variation for Phelipanche species

1. A G R I C U L T U R A L U N I V E R S I T Y O F A T H E N S Lyra1, D., Economou1, G. and Kotoula-Syka2, E.1. Agricultural University of Athens Hellas2. Democritus University of Thrace Orestiada HellasE-mail: dionyssialyra@yahoo.com Host-parasiteinteractionrevealsinter- andintraspecificvariationfor Phelipanchespecies 2nd International Conference on«Novel and Sustainable Weed Managementin arid and semi-arid agro-ecosystems» 7-10 September Santorini Hellas

2. Introduction Results Material & Methods Discussion & Conclusions O. cumana Ph. aegyptiaca Theory building (Gianniantonio Domina 2005) Ph. ramosa O. crenata O. minor

3. Introduction Results Material & Methods Discussion & Conclusions Theory building Broomrapes as holoparasites depend on their host-plants for resources in order to secure their survival and perpetuation

4. Introduction Results Material & Methods Discussion & Conclusions O. crenata Ph. ramosa O. cumana Orobanche and Phelipanche species A varying degree of host-plant specificity Ph. aegyptiaca O. minor

5. Introduction Results Material & Methods Discussion & Conclusions What is host specificity?

6. Introduction Results Material & Methods Discussion & Conclusions Hosts Broomrapes HOST SPECIFICITY Seeds Root system 5-Deoxystrigol Stimulants Orobanchol 2‘-epi-Orobanchol

7. Introduction Results Material & Methods Discussion & Conclusions During host-parasite interaction, A VARIATION has been observed from both sides which has to do with………

8. Introduction Results Material & Methods Discussion & Conclusions 1st case …stimulants Broomrape species Hosts Solanaceae Cannabidaceae Compositae Cruciferae Cucurbitaceae HOST SPECIFICITY

9. Introduction Results Material & Methods Discussion & Conclusions 2nd case … variable response Broomrape populations Host HOST SPECIFICITY Pop. 1 Pop. 3 Pop. 2 Pop. 4

10. Introduction Results Material & Methods Discussion & Conclusions Hosts Broomrapes Broomrape seeds demonstrate different sensitivity in the biochemical stimulus derived from plant-host roots HOST SPECIFICITY Not all host plants do they exude substances with the same chemical composition The main research objective of our study

11. Results Introduction Material & Methods Discussion & Conclusions Why are we interested in studying population diversity? Populations are categorized according to the level of divergence between them Variability (morphological, genetical, physiological, spatial heterogeneity) Hybrids / Subspecies (Ph. ramosa / Ph. aegyptiaca) Races (O. cumana) Host-specificity is one of the driver of genetic divergence Impact on decision-making processes for Orobanche control

12. Results Introduction Material & Methods Discussion & Conclusions Sampling 2002-2004 Broomrape plants were collected from naturally parasitized tobacco and tomato crops

13. Results Introduction Material & Methods Discussion & Conclusions Tobacco Ph. aegyptiaca Ph. ramosa / Ph. aegyptiaca Ph. ramosa

14. Introduction Results Material & Methods Discussion & Conclusions Tomato Ph. ramosa

15. Introduction Results Material & Methods Discussion & Conclusions 20 Phelipanche ramosa populations 28 Phelipanche aegyptiaca populations

16. Introduction Results Material & Methods Discussion & Conclusions • 1st experiment • Hosts:2 rapeseed varieties (EXACT, CALIFORNIA) - tobacco • 3 Phelipanche ramosa populations • 4 Phelipanche aegyptiaca populations • 2nd experiment • Host: tobacco • 13 Phelipanche ramosa populations • 6 Phelipanche aegyptiaca populations • 3rd experiment • Host: tomato • 18 Phelipanche ramosa populations • 9 Phelipanche aegyptiaca populations

17. Introduction Results Material & Methods Discussion & Conclusions MEASUREMENTS • Germinated seeds • Formed tubercles Plastic bag assays were used to study hosts and holoparasite interactions in vivo

18. Introduction Results Material & Methods Discussion & Conclusions Statistical analysis * Data did not follow Normal Distribution * Kruskal – Wallis test / Nemenyi test * Box-Whisker plot Median Data range Outliers Mean Interquartile range

19. Results Introduction Material & Methods Discussion & Conclusions 1st experiment C a n o l a – To b a c c o

20. Interspecific variability Germination (%) Formed tubercles b Ph. ramosa Ph. ramosa b a a a a Ph. aegyptiaca Ph. aegyptiaca c b b a b a

21. Intraspecific variability (Phelipanche populations collected on tobacco same region-same year) f e e O. ramosa O. ramosa O. ramosa O. aegyptiaca O. aegyptiaca d d d d bc Germination (%) c c ab ab a c c b b a a a a O. aegyptiaca B r o o m r a p e p o p u l a t I o n s B r o o m r a p e p o p u l a t I o n s B r o o m r a p e p o p u l a t I o n s O. ramosa O. aegyptiaca c e O. ramosa O. ramosa O. aegyptiaca O. aegyptiaca d d b Formed tubercles b c c a ab bc a a a a a a a a a a B r o o m r a p e p o p u l a t I o n s B r o o m r a p e p o p u l a t I o n s B r o o m r a p e p o p u l a t I o n s CALIFORNIA EXACT TOBACCO

22. Ph. ramosa‘s seeds germinated more by tobacco • More host-specific • Ph. aegyptiaca’sseeds germinated more by canola • Less host-specific • Less tubercles on canola root system • More tubercles on tobacco root system results

23. Results Introduction Material & Methods Discussion & Conclusions 2nd experiment Tobacco

24. Interspecific Variability Ph. aegyptiaca Ph. ramosa a Phelipanchespecies b Germination (%) Ph. aegyptiaca Ph. ramosa a Phelipanchespecies a Formed tubercles

25. Intraspecific variability O. aegyptiaca O. ramosa Region 2 2004 Region 1 Collection year 2002 Region 2 2004 Region 1 2003 Germination (%) Ph. ramosa populations collected on tobacco different regions-different years O. ramosa O. aegyptiaca Region 2 2004 Region 1 Collection year 2002 Region 2 2004 Region 1 2003 Formed tubercles Phelipanche populations

26. results • Ph. ramosa‘s seeds germinated more compared to Ph. aegyptiaca’s seeds • The number of tubercles was not statistical different for both species • High variability among and within regions • High variability among and within collective years

27. Results Introduction Material & Methods Discussion & Conclusions 3rd experiment Tomato

28. Interspecific Variability Ph. aegyptiaca Ph. ramosa a Phelipanchespecies b Germination (%) Ph. aegyptiaca Ph. ramosa a Phelipanchespecies b Formed tubercles

29. Intraspecific variability Region 1 2004 Region 2 2004 Region 3 2003 Region 4 2004 Region 3 Collection year 2002 Germination (%) Ph. ramosa populations collected on tobacco different regions-different years O. aegyptiaca O. ramosa O. aegyptiaca O. ramosa Region 3 Collection year 2002 Region 4 2004 Region 1 2004 Region 2 2004 Region 3 2003 Formed tubercles Phelipanche populations

30. results • Ph. ramosa‘s seeds germinated more compared to Ph. aegyptiaca’s seeds • The number of tubercles was statistical different for both species • High variability among and within regions • High variability among and within collective years • Ph. ramosa seems to be more host-specific

31. Results Introduction Material & Methods Discussion & Conclusions Why were not many tubercles formed on canola root system by Ph. ramosa (1st experiment)? • Tobacco – a traditional crop • Canola – a newly introduced cultivation Why were not many tubercles formed on tobacco root system by Ph. ramosa, although germination was high (1st experiment)? • Tobacco variety • Second level of resistance Are Ph. aegyptiaca/Ph. ramosa highly host-specified species ? No

32. Results Introduction Material & Methods Discussion & Conclusions Where can population variability be attributed? Massive collections of seeds Weight Shape Size Seed coat Genetic material Physiological age Dormancy

33. Results Introduction Material & Methods Discussion & Conclusions Spatial heterogeneity Climate Landscape Topography Soil

34. Sasefharistopoli