34-6 Identifying the Promising Drought Tolerant Genotypes Having High WUE Using Extreme Values of d 13C and d 18O Ratios.

See more from this Division: C02 Crop Physiology and Metabolism
See more from this Session: C-2/C4 Graduate Student Oral Competition - I

Monday, November 7, 2016: 9:15 AM
Phoenix Convention Center North, Room 225 B

Avjinder Singh Kaler, University of Arkansas, Fayetteville, AR and Larry C. Purcell, Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, AR
Abstract:
High water use efficiency (WUE) genotypes could be used to improve drought tolerance under water-limited conditions. However, increased WUE is often associated with reduction in transpiration (T), which is often accompanied by a reduction in biomass. In this research, the 13C:12C   13C) and 18O:16O  18O) ratios were used as surrogate measurement for WUE and T, respectively. From a panel of 373 MG IV accessions, five genotypes from extreme groups having either high or low  13C and for having high or low  18O were chosen based on their phenotypic values and marker effects, similar to methods used in genomic selection. The study’s objective was to identify the genotypes with high WUE associated with relatively high T, and hence, high rate of biomass production. Growth chamber and field experiments were conducted to evaluate the different extremes under well-watered and drought conditions. In the growth chamber experiment, transpiration data, based on gravimetrical measurements, and WUE were estimated. Measured WUE in this study was positively correlated to both  13C and  18O. In the field experiment, canopy wilting and temperature were recorded. In the growth chamber experiment, significant difference in extreme groups and genotypes within group were observed. The genotype group having high  13C and high  18O also had higher WUE. From the field experiment, extreme group and genotypes within group showed significant differences for canopy temperature and wilting. Genotype PI567572B had both higher WUE and also had slower canopy wilting.

See more from this Division: C02 Crop Physiology and Metabolism
See more from this Session: C-2/C4 Graduate Student Oral Competition - I