Rice adaptation pathways in response to heat stress at anthesis

Lafarge Tanguy, Julia Cécile, Ahmadi Nourollah, Dingkuhn Michaël. 2015. Rice adaptation pathways in response to heat stress at anthesis. In : International Plant Physiology Congress: "Challenges and Strategies in Plant Biology Research”. Indian Society for Plant Physiology. New Delhi : Indian Society for Plant Physiology-JNU, Résumé, 1 p. International Plant Physiology Congress: "Challenges and Strategies in Plant Biology Research”. 3, New Delhi, Inde, 11 Décembre 2015/14 Décembre 2015.

Note générale : Tanguy Lafarge est l'expert invité du Cirad

Résumé : Coping with heat stress involves different options that account for the ability of plants to escape (early anthesis time), avoid (panicle cooling through transpiration) or tolerate (presence of genes of interest) heat at flowering. First, variability in the time of day of anthesis was correlated with the mean of climatic variables calculated for the 7-day period before flowering, over four distinct seasons and four contrasted varieties. The best predictive variables (negative correlations) were Tmin and VPD, with high values of both being associated with early times. Second, depending on conditions, panicle temperature varied between 9°C below and 2°C above air temperature at 2 m. A significant positive correlation was obtained between spikelet sterility rate and maximum panicle temperature at flowering, whereas no correlation was obtained with air temperature. By extrapolation, this correlation predicted minimal sterility with a panicle temperature of 30 °C, and 50 % sterility with a panicle temperature of 33-34 °C. Third, a genome-wide association study of the sterility rate of 167 traditional and modern varieties (grown for six consecutive days at 37°C between 8 am and 2 pm at anthesis) detected 91 significant associations grouped into 12 independent regions located on eight chromosomes. The highest heat tolerance was detected for N22, an aus variety from India, and Peh Kuh, a traditional indica variety from Taiwan. Avoidance and tolerance appear as main genetic improvement pathways, whereas sensitivity of time of day of anthesis to air temperature and humidity seems already effective within the rice crop. (Texte intégral)

Mots-clés libres : Time of the day of anthesis, Panicle temperature, Panicle cooling through transpiration, Genome-wide association study

Classification Agris : F60 - Physiologie et biochimie végétales
F30 - Génétique et amélioration des plantes
H50 - Troubles divers des plantes

Auteurs et affiliations

• Lafarge Tanguy, CIRAD-BIOS-UMR AGAP (FRA)
• Julia Cécile
• Ahmadi Nourollah, CIRAD-BIOS-UMR AGAP (FRA) ORCID: 0000-0003-0072-6285
• Dingkuhn Michaël, CIRAD-BIOS-UMR AGAP (PHL)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/583522/)

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