Identification of heat tolerant wheat lines showing genetic variation in leaf respiration and other physiological traits uri icon

abstract

  • A total of 140 diverse spring wheat lines were characterized for agronomic and physiological traits under hot field conditions, and a subset of thirteen were selected for dark leaf respiration studies (R-d). These genetic resources included synthetic-derived lines, landraces, landrace-derived lines, bread wheats, and durum wheats. Initial phenotyping showed that better heat-adapted genotypes (best yielding) exhibited high early biomass (assessed by normalized difference of vegetative index, NDVI), high grainfilling rates, and low canopy temperatures. As for other studies R-d increased as temperature increased (within the range of 15-40 degrees C), and decreased with plant age. Correlations between R-d and leaf temperature ranged between 0.50 and 0.85. R-d was negatively associated with yield when recorded at 30-35 degrees C during anthesis and grainfilling. Comparisons between wheat groups showed that synthetic-derived materials expressed lower leaf respiration rates and larger yields than the other groups at warm temperatures.

publication date

  • 2017
  • 2017