Water productivity and growth parameters of Fawn-tall fescue and Tekapo-orchard grass under deficit irrigation in arid zones

Produtividade da água e parâmetros de crescimento de Festuca Fulvo-Tall e Capim-pomar Tekapo sob irrigação com déficit em zonas áridas

Abstract

This study aimed to determine the drought stress response of Fawn-tall fescue and Tekapo-orchard grass and investigate a drought stress resistance marker. Grass genotypes were grown under four Irrigation treatments I1 equivalent to 0.3 standard crop evapotranspiration (ETc), I2 equivalent to 0.65 ETc, I3 equivalent to 0.75 ETc, and I4 equivalent to 1.2 ETc. Plant height, fresh weight, dry weight were measured and the Water productivity (WP) were calculated. The results showed a reduction in the growth of both grass genotypes as the drought stress increased as indicated by the shorter plants and reduction in fresh and dry weight. However, the WP results showed that the Fawn-tall fescue endured the drought stress better than the Tekapo-orchard grass as indicated by the constant values of the plant WP across the tested irrigation treatments. The results was confirmed by the amplification of dehydrin genes where Fawn-tall fescue was found to be homozygous for dehydrin genes.

Keywords:
Fawn plant; Tekapo plant; water deficit; dehydrin; genetic variability; drought stress