Thermotolerance of Pearl Millet and Maize at Early Growth Stages: Growth and Nutrient Relations

Abstract

Thermotolerance of pearl millet (Pennisetum glaucum cv. ICMV-94133) and maize (Zea mays cv. Golden) was assessed at germination and vegetative stage. Final percentage of germinated seeds and rate of germination (number of days to 50 % germination) decreased due to high temperature (45 °C) similarly in the both species. In contrast, at the vegetative stage, high temperature (38/27 °C) caused a significant reduction in shoot dry mass of maize, whereas this attribute remained almost unchanged in pearl millet. Relative growth rate and net assimilation rate (NAR) increased significantly in pearl millet due to high temperature, but in contrast, in maize NAR was slightly reduced. Concentrations of N, P, and K in the shoots of both species increased at high temperature, but N accumulation was more pronounced in pearl millet than in maize. High temperature caused a marked increase in both shoot and root Ca 2+ concentration in maize, but it did not affect that of pearl millet. S concentration in the shoots of maize decreased significantly due to high temperature, whereas that in pearl millet remained unaffected. Shoot Na + concentration of both species was not significantly affected by high temperature. High temperature caused a significant increase in uptake of N, P, and K + in pearl millet, but the uptake of Ca 2+ , Mg 2+ , Na + and S remained unaffected in this species. In contrast, in maize, a significant increase in uptake of K + and Ca 2+ , and a decrease in uptake of N, S, Mg 2+ , and Na + were found at high temperature. Overall, maize showed lower tolerance to high temperature compared with pearl millet.

Heat shock increases oxidative stress to modulate growth and physico-chemical attributes in diverse maize cultivars

“…In wheat, maize and barley, there is a negative correlation between the plant yields and HT stress (Lobell and Field, 2007). The seed germination, seedling emergence and its establishment is extremely affected by HT in a number of plant species, for example, pearl millet and maize (Ashraf and Hafeez, 2004). High temperature changed the seed composition, seed protein expression profiles and reduced the seed germination and vigor, and thus appeared to determine the seed quality attributes (Egli et al, 2005).…”

Evaluation of Maize Hybrids for Tolerance to High Temperature Stress in Central Punjab

“…Being a C4 plant, maize is capable of utilizing solar energy more efficiently and can tolerate relatively high temperature (Ashraf and Hafeez, 2004) up to a crucial factor. High temperature has adverse effect on the growth and development of plants (Noohi et al, 2009) and the yield may be reduced by 101 kg ha -1 day -1 when the temperature reaches up to 35 0 C during pollination and grain filling stage (Smith, 1996).…”

Screening Of Different Okra Genotypes Against Heat Stress Okra to heat stress

“…Major effect of high temperature is on shoot length which reduced the first intermodal length resulting in death of plants (Hall, 1992). Heat stress caused significant declines in shoot dry mass, relative growth rate (Ashraf and Hafeez, 2004). Heat stress caused considerable damages including the burning of the leaves and twigs, wilting and burn spots on leaves and stem, leaf senescence (Vollenweider and Gunthardt-Goerg, 2005).…”