“The argentine wild Helianthus annuus L. genetic resource”.

CANTAMUTTO M; POVERENE M; PRESOTTO A; ALVAREZ D; LENARDON S , ; RODRÍGUEZ H; MARTÍN SÁNCHEZ J; FERNANDEZ MORONI I; GIOLITTI F ; GARAYALDE A; HAUCKE A; BELLIDO A; FRAYSEE M

Simposio; 8TH EUROPEAN SUNFLOWER BIOTECHNOLOGY CONFERENCE; 2010

Trakya Agricultural Research Institute Edirne, Turkey.

Wild H. annuus from Argentina provides resistant genes for Puccinia heliantii tolerant sunflower varieties released by the middle of the past century. Naturalized wild populations currently located between S 32.0° to S 37.2° latitude could be a valuable genetic resource to sunflower crop. To test this hypothesis, five wild populations were selected to represent different original environments in a common garden study. Their plants showed normal chromosome behavior at diakinesis. Two of those populations normally fertilized (>70%) the CMS PET1 A10 inbred line when pollen was applied daily. Fruit set was reduced (<30%) with one accession, collected in the more humid environment when pollen was applied at a 3-day frequency. Another one, collected in the driest environment, showed high fruit set (>60%) non differences with DK4000 at 3-day pollination interval. All wild populations restored more than 80% fertility of CMS PET1 HA89 and CMS PET1 A10 inbred lines at F1 generation, but none of them restored the CMS RES1 HA89, with H. resinosus cytoplasm. The fertility of a male sterile source from Las Malvinas population was partially restored (66%) by RHA274 line, but the restorers RPET2, R49, R432 and R307 failed to produce more than 10% of fertile progenies at F1 generation. Male fertility restoration over 95% was obtained using maintainer line B10 pollen. The fatty acid content differentiated one population from Entre Ríos, with saturated fatty acid over 107 g kg-1. Another population from La Pampa, with probable introgression of H. petiolaris, showed high level (> 50%) of resistance to Sunflower chlorotic mottle virus (SuCMoV). The five wild populations did not show tolerance to imazaphyr sprayed at 4-6 leaf stage at 2X doses (160g ha-1). The population collected in the southern and coolest point of the geographic distribution of wild sunflowers, showed high tolerance to low temperature (15/5°C, neutral day) at initial stages (<3 expanded leaves). Eleven morpho-physiological traits differenced the wild populations in their response to water stress. A population from Córdoba province, collected in a dry habitat, with an overall good performance to drought, showed higher germination (>80%) under water stress (-0.4 MPa) imposed by polyethylen glycol 6000. This population and another from southern Buenos Aires showed the lowest leaf temperature increase (<10%) and the highest foliar specific density under water stress (irrigation covering 50% of potential air demand) during R4 to R6 stages. It could be concluded that wild H. annuus naturalized in central Argentina can supply some useful traits for sunflower breeding.