Effects of Hypoxia on Barley Growth at Seeding Stage

Abstract

Oxygen dificiency in barley root system (hypoxia) is an important problem of barley production in paddy field. Three different hypoxia tolerance barley genotypes, SMG1, FNBLS#140 and BRBRF9629, wee used to detemine the effects of hypoxia on growth, photosynthetic effciency, dry matter accumulation rate and partitioning coefficients of assimilate to the root of barley seeding, All genotypes were grown in stagnant agar nutrient solution (assimilate to the root of barley seeding. All genotyped were grown in stagnane agar nutrient solution 9as hypoxic condition) and aerated nutrient solution (as control) in plant growth chambers at Lampang Agricultural Research and Training Center during March-April 199. The results showed that hypoxia stress reduced plant growth, expecially root growth rate. All barley genotypes had also less dry matter partitioning of assimilate to their roots . Increasing photosynthetic rate for hypoxic adaptation was due to be highly leaf chlorophll efficiency. Among three genotypes, SMG1 had a consistent in photosynthetic efficiency under hypoxia. Thus it could be slightly lower shoot and plant groth aate. Whereas FNBLS#140 had low photosynthetic rate after 3-5 days of hypoxia, lower growth rates and dry matter partitioning of assimilate to the roots than SMG1. BRBRF9629 could not maintain photosynthetic rate after hypoxia. It caused to be the lowest growth rates and dry matter partitioning of its assimilate to the roots.