Titanium dioxide nanoparticles model growth kinetic traits of some wheat cultivars under different water regimes

Abstract

Deficit irrigation affected drastically growth kinetics and leaves traits with variant degrees drawing the tolerance or sensitivity of four wheat cultivars which recorded from pre- to post-anthesis stage. The main susceptibility characters of hypersensitive cultivar Sohag 3 were reduction of photosynthetic efficiency (chlorophyll and photosynthetic rate), leaf greenness (low leaf area index; LAI), accelerated leaf aging (low biomass duration; BMD and leaf area duration; LAD), thinner and lighter leaves (high specific leaf area; SLA and high leaf area ratio; LAR) which dramatically reflected on low net assimilation rate; NAR and unit leaf rate; ULR, hence diminished absolute growth rate; AGR and relative growth rate; RGR, the vice versa was displayed by the most tolerant cultivar Seds 12. Intermediated response was manifested by cultivars Benisuif 5 and Sakha 93, since the former was close in response to cultivar Seds 12 and the latter showed the main characters of cultivar Sohag 3 but in lower degree. The photo-catalytic property of TiO2-NPs seemingly accomplished improvement of leaves and growth kinetics traits by fertigation the soil of wheat cultivars growing at different water regimes. TiO2-NPs fertigation promoted leaf characteristics through production of thicker and heavier leaves as well as promoting leaf longevity by enhancement of BMD and LAD. Thus, TiO2-NPs activated production of vigor and well-constructed leaves with higher chlorophyll and photosynthetic rate thereby, high LAI, hence higher values of RGR, AGR, ULR and NAR.