Leaf Anatomy of Zea mays L. in Response to Water Shortage and High Temperature: A Comparison of Drought-Resistant and Drought-Sensitive Lines

1991 ◽  
Vol 152 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Zoran Ristic ◽  
David D. Cass
1982 ◽  
Vol 9 (2) ◽  
pp. 247 ◽  
Author(s):  
BD Cooke

Rabbits given an excess of air-dry food but only small amounts of drinking water had a lower food intake and lost more weight than those given food and water freely. They lost weight because they had less digesta in the gut and less water in the skin, and had catabolized more tissue. Their response to water shortage was similar to that seen in other grazing mammals. With low food intake, gut contents fell and the digestibility of food rose, while the daily mass of and water loss in faeces fell; the moisture content in faeces remaining the same. Dehydrated rabbits produced relatively small amounts of urine, up to 1.9 M urea, which was twice as concentrated as that of rabbits given water freely. The rabbits were not able to reduce their requirement for water to less than 55% of their total intake of food and water. As pasture species in mediterranean-type environments become relatively dry in summer and contain only 10 to 5% water, a shortage of water in natural pastures in those areas may, therefore, limit the amount of food which rabbits can use, and the ability of rabbits to survive in summer would, therefore, depend upon the availability of succulent, drought-resistant perennial vegetation.


1974 ◽  
Vol 54 (1) ◽  
pp. 71-78 ◽  
Author(s):  
R. B. HUNTER ◽  
L. A. HUNT ◽  
L. W. KANNENBERG

The open-pollinated corn (Zea mays L.) cult Gaspé Flint and three hybrids, Guelph GX122, Harrow 691, and Pioneer X306, were selected to examine the effects of photoperiod and temperature on the number of days to tassel initiation. The range of maturity of this material varied from extremely early to subtropical. The experiments, conducted in growth cabinets, examined photoperiods of from 10 to 20 h in 21/2-h increments. Constant day–night temperatures examined were 20, 25, and 30 C. Photoperiod and temperature affected number of days to tassel initiation. The response was not consistent for each genotype. As daylength increased from 10 to 20 h all but the earliest genotype, Gaspé Flint, took longer to reach tassel initiation. The latest hybrid, Pioneer X306, was affected relatively more by photoperiod. The delay in tassel initiation with longer photoperiods was apparent at all temperatures; however, the magnitude of the response was less at the high temperature. With longer photoperiods, there was an increase in the amount of vegetative growth and development prior to tassel initiation. This was apparent from the greater number of emerged leaves, the longer stem length, and the greater plant dry weight at tassel initiation.


2021 ◽  
pp. 146-151
Author(s):  
L. Priyanandhini ◽  
M. K. Kalarani ◽  
A. Senthil ◽  
N. Senthil ◽  
K. Anitha ◽  
...  

Maize (Zea mays L.) is the most important food and feed crop grown under diverse soil and climatic conditions. Among the cereals, demand for maize is increasing year after year, but fluctuation in climatic conditions especially the temperature extremes is the current and future threat in maize cultivation. Each degree Celsius increase in global mean temperature causes yield reduction up to 7.4 per cent in maize. The high temperature stress impact at the reproductive stage affects grain filling rate and duration. Adaptation of maize crop to future warmer climatic conditions requires a better understanding of physiological responses to elevated temperatures. With this view, a pot culture experiment was conducted at the Department of Crop Physiology, TNAU, Coimbatore during the summer season of 2020. Two maize inbreds viz., UMI 1230 and CBM-DL- 322 were taken for the study and exposed to high temperature stress treatments viz., T1 - ambient, T2 - ambient+4°C and T3 - ambient+6°C (44°C) for 10 days during the reproductive stage to assess the changes in biochemical and yield traits. The ambient+4ºC treatment revealed that the maize inbred line CBM-DL-322 recorded lower malondialdehyde content with over production of antioxidant enzyme activity (superoxide dismutase, catalase and ascorbate peroxidase). Cob weight and seed set parentage showed a negative correlation with both elevated temperatures. It is concluded that the maize inbreds line CBM-DL- 322 performed better at an elevated temperature at ambient+4°C and recorded more cob weight (57.09g) compared to UMI 1230 inbred (43.56g).


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