Comparative physiology of Australian commercial rice cultivars to salinity stress in controlled environment and the field

Abstract

Salinity intrusion into agricultural lands in rice-producing countries around the world has become a serious threat to food security. Currently, more than 960 million hectares of productive land is adversely affected by salinity and is expected to grow in the future. This problem is exacerbated by the projected increase in world population from the current 7.2 to 9.6 billion by 2050. The cultivated rice (Oryza sativa) tolerates 10 dSm-1. This study used morpho-physiological methods including gas exchange measurement, microelectrode ion flux estimation (MIFE) and agronomic measurements to screen salinity tolerance levels of two Japonica (Koshihikari and Reiziq) rice genotypes and one Indica (Doongara) genotype. In addition, this is the first time that four basic ion fluxes were measured using MIFE in both glasshouse and field conditions to screen rice for salinity tolerance. The effects of salinity stress on photosynthetic activities, ion fluxes and growth parameters of the three rice genotypes under glasshouse conditions and in the field were also examined. Variations in the response of the three cultivars to salinity stress were found, thus providing evidence that morpho-physiological basis of salinity stress tolerance can be applied to improve the salinity stress tolerance of this important crop. This may allow the exploitation of salt affected marginal lands and could positively contribute to global food security.

Date of Award	2018
Original language	English